Macros

[Alan Browne]

http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/


--
"There were, unfortunately, no great principles on which parties
were divided – politics became a mere struggle for office."
-Sir John A. Macdonald

[dadiOH]

Alan Browne wrote:
> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/

Those are nothing short of EXCELLENT!!

--

dadiOH
____________________________

Winters getting colder? Tired of the rat race?
Taxes out of hand? Maybe just ready for a change?
Check it out... http://www.floridaloghouse.net

[PeterN]

On 3/16/2013 8:24 AM, Alan Browne wrote:
>
> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/
>
>
>

Really neat.
They are a classic example of really nice images, that would not do well
in a camera club competition. I wish I had taken them.

--
PeterN

[Usenet Account]

Curious why you say they would NOT do well in a camera club? Just
wondering?

--
This space intentionally left blank.

[PeterN]

Many judges would say: the hot spots are distracting; parts of the
creatures are outside the image area, etc.
Please note the above is not my impression, but is intended to be a
commentary of the weaknesses of camera club judging. I have often said
that Cartier-Bresson, would not do well in camera club competitions.


--
PeterN

[Rob]

Agree with your comments, camera club judges are full of themselves on
the night, nit picking, they can't correctly evaluate the elements of an
image and ridicule the content. As an example some time ago had a image
evaluated and the comment was the horizon was not straight, funny about
that it had lens curvature. Another example was architecture, where
verticals should be vertical or over over emphasised, looking up at a
tall building, the judge picked on one as not vertical which should have
been, but there were 2 others out of whack as well, but no criticism of
the fact but given awards!

I have even pointed out plagiarism of images and part images, to the
committee, ripped off the web, and they have condoned the use of such
images, to the extent where the image has been best in section. I was
being a pain in the arse to them.

I'm sure other images being presented in competitions, were not setup or
photographed by the author, as they didn't show a consistent standard of
such photographer compare with there other submissions.

What does amaze me is the judges will critique an image but can't
explain why or give their opinion how to rectify the perceived fault.

One particular night there was this judge who insisted using "Um" all
the time, this irritates me as its them catching up with their thoughts,
anyhow this was so annoying that I started to count the number of time
she used "Um" and the intervals between. Results basically, 700, at 20
second intervals, yep - over 3 hour period.
What a long boring night that turned out to be.

Camera clubs live in there own little world and stay in a rut.

[Tony Cooper]

The more I read about other people's views and comments about their
camera clubs, the more I feel that the camera club I belong to is
doing competitions the right way. I don't always agree with the
judge's critiques, or always agree with the first place choices, but
the judges do a good job of explaining why a photo is rated high or
low and what should have been done if the rating is low.

Maybe it's because it's a large club with an average attendance of 75
to 100 members so the pool to draw from for the in-house judges (two
in-house and one outsider for each competition night) or maybe it's
because the judges are given the submissions several days before the
competition night and thus have time to prepare their critiques.

The only real objection I have to the competitions is that submissions
are not required to be "fresh". So, instead of shooting to the
mandate, most members pull shots from their archives and the image
might have been taken several years ago.


--
Tony Cooper - Orlando FL

[Savageduck]

On 2013-03-16 05:24:44 -0700, Alan Browne
<alan....@FreelunchVideotron.ca> said:

>
> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pi
> ctures/

Great stuff!!

I have two apps for my iPad, 500px and the Guardian "Eyewitness" apps
and I have been immersing myself in some of the amazing images
presented in both.
500px provides shots of incredible quality in their app, including
these macros;
< https://dl.dropbox.com/u/1295663/FileChute/500px-001.PNG >
< https://dl.dropbox.com/u/1295663/FileChute/500px-002.PNG >

"Eyewitness" runs a continuous free gallery of 50 images, adding new
shot and removing the oldest each day. They offer a different access
for a subscription;
<
https://dl.dropbox.com/u/1295663/FileChute/Photo%20Jan%2025,%2010%2054%2034%20PM.png
>
<
https://dl.dropbox.com/u/1295663/FileChute/Photo%20Feb%2020,%201%2053%2033%20PM.png
>
<
https://dl.dropbox.com/u/1295663/FileChute/Photo%20Mar%2007,%205%2006%2027%20AM.png
>
...and
<
https://dl.dropbox.com/u/1295663/FileChute/Photo%20Mar%2013,%201%2024%2034%20AM.png
>


--
Regards,

Savageduck

[Savageduck]

...er
>
"Eyewitness" has a 100 shot continuous feed gallery.

--
Regards,

Savageduck

[Rob]

Your club must be doing something right to have so many in attendance
making for an interesting participation for its members

What you are saying seems quite good and the combination of judging
keeps the standard very high.

Giving judges submissions in advance is an excellent way as the judges
are not over whelmed by so much to comment on.

[Tony Cooper]

Yes, advance preparation is a good feature for judges. Entries are
submitted online one week in advance. They are then sent to the
judges in password-protected files and the judges review them at home,
grade them, and prepare their critiques. I notice, during the
critiques, that judges read from their pre-prepared notes. Scores are
an average of the three judge's individual scores. Each entry is
commented on by only one judge (rotating through the three), but the
other two can add a short comment if they want to.

All competitions are flawed in that all judges have personal biases
and preferences for certain elements in a photo. Judging is
subjective. But, the prize money for first place is a $25 gift card
from a sponsor, so it's not that big a deal other than the
recognition.

[PeterN]

If I took pictures like that, I would unretire in a New York minute.
Are they yours?

I have problems believing that they were taken with an iPad.



--
PeterN

[PeterN]

On 3/17/2013 12:50 AM, Rob wrote:

<snip>

>
> Camera clubs live in there own little world and stay in a rut.

Not all. Just some of the judges. My club has 60 members. On competition
nights we average about 40. On other nights, attendance varies, but
rarely less than 30. We have filed trips every Sunday. about 15 to 20
show up. Some just come for breakfast, where we get into discussions.
About two weeks ago two of our members gave a presentation of shooting
butterflies. Today, we went to a butterfly exhibit. (Yes it was
indoors.) On my recent trip to FL, I was kept busy almost every day,
shooting with members oaf my club.


--
PeterN

[Tony Cooper]

A second club I belong to has about 40-50 members. I joined them
yesterday for a field trip to a car show. I'll stop and take a shot
or two at a car show, but I'm not a big fan. Too many people standing
around the cars, the sun is never right for the shot I want, and I've
never been able to get my circular polarizer to do its thing.

I went for the social aspect. Eight of us had a meal together and
chatted about photography. This smaller club is more social than the
larger club I belong to, but the larger club also has field trips.

Here's why I don't like car shows:

http://dl.dropbox.com/u/64147677/2013-03-16-75.jpg

All the people, the background, and the signs in the window of this
Packard. I do shoot some close-up of bits and pieces of cars to avoid
the problem. This one's a 1939 Ford:

http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg

[Savageduck]

I wish!!
...but I certainly find them inspiring.

> I have problems believing that they were taken with an iPad.

Nowhere did I say they were taken with an iPad.
500px has an app for ipad, iPhone, & Android devices which gives you
access to their galleries.
< http://500px.com/apps >

...and The Guardian has their "Eyewitness" app with free and
subscription options ( I use the free version) which has a gallery of
100 shots. A new shot is added, and the oldest is removed daily.
< https://itunes.apple.com/app/the-guardian-eyewitness/id363993651?mt=8 >

On the iPad with the "Retina" display, the impact of those images is
quite amazing. What I posted were screen captures from my iPad.

If I recall, you have an iPhone, get the 500px app and do some
exploring. Obviously having the larger display of the iPad is nice, but
you will have access to their "popular", Editor's Choice", "Upcoming",
& "Fresh" galleries. Enjoy.


--
Regards,

Savageduck

[Trevor]

"Rob" <mesa...@google.com> wrote in message
news:ki3hva$acq$1...@dont-email.me...

The real question is why you would bother then rather than get out and take
pictures for your own pleasure, and/or paying clients, rather than approval
from stupid camera club judges?

Trevor.

[Trevor]

"Tony Cooper" <tonyco...@gmail.com> wrote in message
news:folak8tnn1tq5140i...@4ax.com...

> The only real objection I have to the competitions is that submissions
> are not required to be "fresh". So, instead of shooting to the
> mandate, most members pull shots from their archives and the image
> might have been taken several years ago.

Why should that matter? A seperate comp for a joint walkabout shooting
session should cover that where people only get to shoot the same subjects
in the same time, for those who prefer that limitation. Frankly I find the
whole idea of such comps rather narcissistic and pointless, but each to
their own.

Trevor.

[Tony Cooper]

On Mon, 18 Mar 2013 13:14:00 +1100, "Trevor" <tre...@home.net> wrote:

>
>"Tony Cooper" <tonyco...@gmail.com> wrote in message
>news:folak8tnn1tq5140i...@4ax.com...
>> The only real objection I have to the competitions is that submissions
>> are not required to be "fresh". So, instead of shooting to the
>> mandate, most members pull shots from their archives and the image
>> might have been taken several years ago.
>
>Why should that matter?

The idea of a mandate is to encourage the photographer to find
something to shoot that he/she might not otherwise shoot and/or to
look at a scene to find something in it that he/she might not
otherwise see. It should expand the photographer's thinking.

Putting a time restraint on it, stirs the photographer to do the above
now instead of going through a couple of thousand archive shots that
might fit the mandate.

> A seperate comp for a joint walkabout shooting session should cover that
>where people only get to shoot the same subjects in the same time,
>for those who prefer that limitation.

To the best of my knowledge, there are no Aborigines that are members
of the camera club I belong to.

>Frankly I find the whole idea of such comps rather narcissistic and
>pointless, but each to their own.

That's OK. Those that aren't interested, or those who aren't willing
to have their efforts judged by others, are not pressed to join in.

[Trevor]

"Tony Cooper" <tonyco...@gmail.com> wrote in message

news:q01dk8ttdbr50v3hu...@4ax.com...

> On Mon, 18 Mar 2013 13:14:00 +1100, "Trevor" <tre...@home.net> wrote:
>>"Tony Cooper" <tonyco...@gmail.com> wrote in message
>>news:folak8tnn1tq5140i...@4ax.com...
>>> The only real objection I have to the competitions is that submissions
>>> are not required to be "fresh". So, instead of shooting to the
>>> mandate, most members pull shots from their archives and the image
>>> might have been taken several years ago.
>>
>>Why should that matter?
>
> The idea of a mandate is to encourage the photographer to find
> something to shoot that he/she might not otherwise shoot and/or to
> look at a scene to find something in it that he/she might not
> otherwise see. It should expand the photographer's thinking.

....in the direction of the mandate, rather than the direction of the
photographers choosing. Can't see the point, but if you are happy, sure
doesn't bother me.

>> A seperate comp for a joint walkabout shooting session should cover that
>>where people only get to shoot the same subjects in the same time,
>>for those who prefer that limitation.
>
> To the best of my knowledge, there are no Aborigines that are members
> of the camera club I belong to.

Am I supposed to laugh?

>>Frankly I find the whole idea of such comps rather narcissistic and
>>pointless, but each to their own.
>
> That's OK. Those that aren't interested, or those who aren't willing
> to have their efforts judged by others, are not pressed to join in.

Exactly, and neither are those who dislike the judges
motives/ability/comments/agenda, or any other reason/complaint given so far.

Trevor.

[Tony Cooper]

On Sun, 17 Mar 2013 23:15:45 -0400, Tony Cooper
<tonyco...@gmail.com> wrote:

>>Frankly I find the whole idea of such comps rather narcissistic and
>>pointless, but each to their own.
>

"Narcissism" is not a word that I would choose to describe the
motivation to participate in competitions. The narcissist is
interested only self, and is excessively vain or egotistical.

The narcissist would be adverse to entering competition because he or
she would not be willing to be judged by others and would assume that
anything he or she created would be superior to the submissions of
others by default.

The true narcissist *does* feel that competitions of this sort are
pointless, though, because he or she feels that his or her submission
is sure to win and therefore going through the motions of entering is
pointless.

Those of us who do enter competitions do so because a) we are proud of
our work, or, b) we want to hear/read how others see our work, or, c)
because we want recognition for our efforts, or, d) a combination of
those reasons.

[Rob]

On 18/03/2013 2:15 PM, Tony Cooper wrote:
> On Mon, 18 Mar 2013 13:14:00 +1100, "Trevor" <tre...@home.net> wrote:
>
>>
>> "Tony Cooper" <tonyco...@gmail.com> wrote in message
>> news:folak8tnn1tq5140i...@4ax.com...
>>> The only real objection I have to the competitions is that submissions
>>> are not required to be "fresh". So, instead of shooting to the
>>> mandate, most members pull shots from their archives and the image
>>> might have been taken several years ago.
>>
>> Why should that matter?
>
> The idea of a mandate is to encourage the photographer to find
> something to shoot that he/she might not otherwise shoot and/or to
> look at a scene to find something in it that he/she might not
> otherwise see. It should expand the photographer's thinking.
>
> Putting a time restraint on it, stirs the photographer to do the above
> now instead of going through a couple of thousand archive shots that
> might fit the mandate.
>
>> A seperate comp for a joint walkabout shooting session should cover that
>> where people only get to shoot the same subjects in the same time,
>> for those who prefer that limitation.
>

After a club outing about 2 months later a subject came up where an
image suitable for the comp, 4 images the same turned up, B&W as well.

> To the best of my knowledge, there are no Aborigines that are members
> of the camera club I belong to.

We have blue eye blonds who are aborigines, nowdays you can't tell :)

[Trevor]

"Tony Cooper" <tonyco...@gmail.com> wrote in message

news:pk3dk8h4cv51nqj8s...@4ax.com...

>>>Frankly I find the whole idea of such comps rather narcissistic and
>>>pointless, but each to their own.
>
> "Narcissism" is not a word that I would choose to describe the
> motivation to participate in competitions. The narcissist is
> interested only self, and is excessively vain or egotistical.

Yep, that's the motivation for many, a desire to be admired by others for
the talent they think they have.

> The narcissist would be adverse to entering competition because he or
> she would not be willing to be judged by others and would assume that
> anything he or she created would be superior to the submissions of
> others by default.

Right, they expect to win, and blame the judges when they don't.

> The true narcissist *does* feel that competitions of this sort are
> pointless, though, because he or she feels that his or her submission
> is sure to win and therefore going through the motions of entering is
> pointless.

Well that's one way to look at it I guess. But the true narcissist expects
to win and needs the admiration.

> Those of us who do enter competitions do so because a) we are proud of
> our work, or, b) we want to hear/read how others see our work, or, c)
> because we want recognition for our efforts,

Exactly my point. But go right ahead, I said straight up each to their own.

Trevor.

[Wolfgang Weisselberg]

Tony Cooper <tonyco...@gmail.com> wrote:

> The only real objection I have to the competitions is that submissions
> are not required to be "fresh". So, instead of shooting to the
> mandate, most members pull shots from their archives and the image
> might have been taken several years ago.

So you're basically saying you should have to re-shoot your
own best shoots if you want them to participate?

-Wolfgang

[Tony Cooper]

This is about mandate shots, not necessarily the "best" shots in one's
archives. If you are going to participate in a competition with a
mandate, and all you are willing to put into it is a trawl through
your archives, I don't think you are entering into the spirit of
things. The mandate should encourage you to go out and find something
that fits.

If it was up to me, I'd announce the mandate three months in advance
and allow only photographs taken within that span. I'd also have
quarterly "Open" competitions where archive shots of any age would be
allowed. This would give the participants three months to find a
mandate submission for each of the eight "fresh" competitions and a
chance every three months to present their favorite archive shot.

Besides, what I think is my "best" shot of a (mandate) might be
bettered if I re-shoot the same scene.

[PeterN]

Then I misunderstood.

>
> ...and The Guardian has their "Eyewitness" app with free and
> subscription options ( I use the free version) which has a gallery of
> 100 shots. A new shot is added, and the oldest is removed daily.
> < https://itunes.apple.com/app/the-guardian-eyewitness/id363993651?mt=8 >
>
> On the iPad with the "Retina" display, the impact of those images is
> quite amazing. What I posted were screen captures from my iPad.
>
> If I recall, you have an iPhone, get the 500px app and do some
> exploring. Obviously having the larger display of the iPad is nice, but
> you will have access to their "popular", Editor's Choice", "Upcoming", &
> "Fresh" galleries. Enjoy.
>

Right now I am having difficulties with my iPhone. So I am not getting
any new apps, but thanks for the suggestions.


--
PeterN

[PeterN]

On 3/17/2013 3:31 PM, Tony Cooper wrote:
> On Sun, 17 Mar 2013 14:14:15 -0400, PeterN

>> <snip>
>>
>>>
>>> Camera clubs live in there own little world and stay in a rut.
>>
>> Not all. Just some of the judges. My club has 60 members. On competition
>> nights we average about 40. On other nights, attendance varies, but
>> rarely less than 30. We have filed trips every Sunday. about 15 to 20
>> show up. Some just come for breakfast, where we get into discussions.
>> About two weeks ago two of our members gave a presentation of shooting
>> butterflies. Today, we went to a butterfly exhibit. (Yes it was
>> indoors.) On my recent trip to FL, I was kept busy almost every day,
>> shooting with members oaf my club.
>
> A second club I belong to has about 40-50 members. I joined them
> yesterday for a field trip to a car show. I'll stop and take a shot
> or two at a car show, but I'm not a big fan. Too many people standing
> around the cars, the sun is never right for the shot I want, and I've
> never been able to get my circular polarizer to do its thing.
>
> I went for the social aspect. Eight of us had a meal together and
> chatted about photography. This smaller club is more social than the
> larger club I belong to, but the larger club also has field trips.
>
> Here's why I don't like car shows:
>
> http://dl.dropbox.com/u/64147677/2013-03-16-75.jpg

If you only take shots like that, I don't blame you. However, I am
surprised that you don't see a lot of good Street shots at a car show,
or any other street festival.

>
> All the people, the background, and the signs in the window of this
> Packard. I do shoot some close-up of bits and pieces of cars to avoid
> the problem. This one's a 1939 Ford:
>
> http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
>
>

Now that's more like it! That shot captures the essence of the car.
Nicely done.

--
PeterN

[PeterN]

Most of the members of my club do not shoot for the approval of judges.
We only submit images to the competition for the critique. I find that
third-party comments, where the people are not afraid to hurt my
feelings, can be quite helpful. Quite often they point out flaws that I
have not seen. The only other person who will give me honest opinions on
how crappy some of my images are is my younger daughter, and I can't
really impose on her all the time. She only works approximately 80 hours
a week.


--
PeterN

[PeterN]

Yes, that can be a good idea. However the commentary on older images can
be quite helpful too. Some people are extremely competitive, some to the
point of almost being aggressive. If these people needed for their ego,
it certainly takes nothing away from me for them to be A-holes. One of
the rules is that all postprocessing be done by the maker. We used to
have a member who was quite open about the fact that he was hiring
somebody to do his postprocessing.

We had another member who would accuse people of stealing his shot if
you walked near him with a camera while he was shooting. As a response
we had a special critique where we all went to one location and the
critique was based solely on shots taken at that time and place.


--
PeterN

[Tony Cooper]

Oh, I do. Like this:
http://tonycooper.smugmug.com/Other/Candids/i-nqnDgnx/0/L/2012-01-21-2G-L.jpg
http://tonycooper.smugmug.com/Other/Candids/i-RFB2zZP/0/L/2012-01-21-1G-L.jpg

At the show where the shot of the Packard was taken, I got this one:

https://www.dropbox.com/s/p3e709onjqayig9/2013-03-16-56.jpg

>> All the people, the background, and the signs in the window of this
>> Packard. I do shoot some close-up of bits and pieces of cars to avoid
>> the problem. This one's a 1939 Ford:
>>
>> http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
>>
>>
>Now that's more like it! That shot captures the essence of the car.
>Nicely done.
--

[PeterN]

While I understand your enthusiasm for street shots, I have little
personal appreciation of that genre.
That being said, I like the last shot. Too bad the little boy was not in
the upper right-hand corner. :-)

>
> At the show where the shot of the Packard was taken, I got this one:
>
> https://www.dropbox.com/s/p3e709onjqayig9/2013-03-16-56.jpg
>
>
>
>>> All the people, the background, and the signs in the window of this
>>> Packard. I do shoot some close-up of bits and pieces of cars to avoid
>>> the problem. This one's a 1939 Ford:
>>>
>>> http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
>>>
>>>
>> Now that's more like it! That shot captures the essence of the car.
>> Nicely done.


--

PeterN

[Savageduck]

What sort of "difficulties" are you having with your iPhone. We have at
least four iPhone users here who might be able to help.


--
Regards,

Savageduck

[PeterN]

It will only recharge from one charging cord.
My wife's iPhone has no such issue, so I know it's not that all of the
other chargers are bad. I took it into Verizon, and they sent me a new
phone. I have not yet returned the old, because I am not certain that
all privacy information has been deleted.

--
PeterN

[Savageduck]

That is odd.
The most frequent issue along those line I have heard of, but not
experienced myself is a bad USB cable. I have never heard of an iPhone
being restricted to a particular charger. I have multiple chargers and
USB cords for the iPhone, Ipad, several vintages of iPod and the
iPhone/iPod connection cable in the glovebox of my E350, all are
interchangeable. So i guess the issue is peculiar to your phone and
replacing it is probably the best solution.

Open the "Settings" app, go to "General", scroll down to "Reset" (it is
the last choice as you scroll down), select "Erase All Content and
Settings". Just don't do that until you have set up your new iPhone
after having backed it up to your PC or iCloud.


--
Regards,

Savageduck

[Elliott Roper]

In article <514da3d6$0$10759$8f2e...@news.shared-secrets.com>, PeterN

<peter.n...@verizon.net> wrote:

> >
> > All the people, the background, and the signs in the window of this
> > Packard. I do shoot some close-up of bits and pieces of cars to avoid
> > the problem. This one's a 1939 Ford:
> >
> > http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
> >
> >
> Now that's more like it! That shot captures the essence of the car.
> Nicely done.

Totally Ace! I don't think I have ever seen a better picture of an old
yank tank. As Peter N says - the essence! The bonnet (engine lid? sorry
I can't think of the right US English) up says car show, but everything
else says drive-in movie. I love it!

--
To de-mung my e-mail address:- fsnospam$elliott$$
PGP Fingerprint: 1A96 3CF7 637F 896B C810 E199 7E5C A9E4 8E59 E248

[PeterN]

Thanks.
I made an appointment with Apple, to see if they can solve the issue.
They advised me to back up the data before I come in. I have backed up
the data, but the new phnoe won't see it. Naturally, I am not doing
anything until the issue is resolved.


--
PeterN

[Tony Cooper]

On Sat, 23 Mar 2013 10:35:11 -0400, PeterN

That whooshes me. The boy in the diaper? Why would it improve the
image if he was in the upper right corner?

>
>>
>> At the show where the shot of the Packard was taken, I got this one:
>>
>> https://www.dropbox.com/s/p3e709onjqayig9/2013-03-16-56.jpg
>>
>>
>>
>>>> All the people, the background, and the signs in the window of this
>>>> Packard. I do shoot some close-up of bits and pieces of cars to avoid
>>>> the problem. This one's a 1939 Ford:
>>>>
>>>> http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
>>>>
>>>>
>>> Now that's more like it! That shot captures the essence of the car.
>>> Nicely done.
--

[Tony Cooper]

On Sat, 23 Mar 2013 18:56:42 +0000, Elliott Roper <nos...@yrl.co.uk>
wrote:

>In article <514da3d6$0$10759$8f2e...@news.shared-secrets.com>, PeterN
><peter.n...@verizon.net> wrote:
>
>> >
>> > All the people, the background, and the signs in the window of this
>> > Packard. I do shoot some close-up of bits and pieces of cars to avoid
>> > the problem. This one's a 1939 Ford:
>> >
>> > http://dl.dropbox.com/u/64147677/2013-03-16-88.jpg
>> >
>> >
>> Now that's more like it! That shot captures the essence of the car.
>> Nicely done.
>
>Totally Ace! I don't think I have ever seen a better picture of an old
>yank tank. As Peter N says - the essence! The bonnet (engine lid? sorry
>I can't think of the right US English) up says car show, but everything
>else says drive-in movie. I love it!

Thank you. The bonnet, in the US, is the hood. You can't see the
hooter button, or horn button as we call it, any of the fenders
(wings), the gas (petrol) tank cap, the trunk (boot), or the muffler
(silencer). You can see the hood through the windshield (windscreen).
This was a 2-door coupe, not a saloon car or a shooting brake.

[Robert Coe]

On Sun, 17 Mar 2013 23:15:45 -0400, Tony Cooper <tonyco...@gmail.com>
wrote:

: On Mon, 18 Mar 2013 13:14:00 +1100, "Trevor" <tre...@home.net> wrote:
:
: >
: >"Tony Cooper" <tonyco...@gmail.com> wrote in message
: >news:folak8tnn1tq5140i...@4ax.com...
: >> The only real objection I have to the competitions is that submissions
: >> are not required to be "fresh". So, instead of shooting to the
: >> mandate, most members pull shots from their archives and the image
: >> might have been taken several years ago.
: >
: >Why should that matter?
:
: The idea of a mandate is to encourage the photographer to find
: something to shoot that he/she might not otherwise shoot and/or to
: look at a scene to find something in it that he/she might not
: otherwise see. It should expand the photographer's thinking.
:
: Putting a time restraint on it, stirs the photographer to do the above
: now instead of going through a couple of thousand archive shots that
: might fit the mandate.
:
: > A seperate comp for a joint walkabout shooting session should cover
: >that where people only get to shoot the same subjects in the same time,
: >for those who prefer that limitation.
:
: To the best of my knowledge, there are no Aborigines that are members
: of the camera club I belong to.

You've lost me in what seems to be a total non sequitur. Obviously I'm missing
something. Can you elaborate to dispel my confusion?

Bob

[David Hare-Scott]

Robert Coe wrote:

>>> A seperate comp for a joint walkabout shooting session should cover
>>> that where people only get to shoot the same subjects in the same
>>> time, for those who prefer that limitation.
>>
>> To the best of my knowledge, there are no Aborigines that are members
>> of the camera club I belong to.
>
> You've lost me in what seems to be a total non sequitur. Obviously
> I'm missing something. Can you elaborate to dispel my confusion?
>
> Bob

Australian Aboriginals were hunter-gatherers who would go on trips sometimes
to find food or for cultural reasons. This was termed 'going walkabout'.
In Oz a person who is missing or travelling with no particular destination
is said to be 'gone walkabout'.

D

[Robert Coe]

On Sun, 24 Mar 2013 11:39:07 +1100, "David Hare-Scott" <sec...@nospam.com>
wrote:

Thanks for the clarification. I sort of knew that "walkabout" was an
Australian term, but I wasn't aware of the implied reference to Aboriginals.

Bob

[PeterN]

The fountains make interesting leading lines, that would go straight to
the little oby. If you have CS6, try a content aware move.



--
PeterN

[Robert Coe]

On Sat, 23 Mar 2013 21:18:08 -0400, PeterN <peter.n...@verizon.net>
wrote:

: the little boy. If you have CS6, try a content aware move.

So what's he going to do? Perch on that palm tree?

Bob

[PeterN]

Right between the fountains. Of course, he might look a tad smaller so
as not to lose perspective.


--
PeterN

[Tony Cooper]

The term "walkabout" is an Australian Aboriginal term meaning a
"journey" in which an adolescent male goes out alone to live in the
wilderness for six months or so. They do so to trace the paths of
their ancestors. It's a rite of passage for Australian Aborigines.

That dispel the confusion?

[Tony Cooper]

On Sat, 23 Mar 2013 21:18:08 -0400, PeterN

I see. It could work, but I don't really like creating the scene. I
may make some minor alterations, but the photo has to stand as it was
for the most part. I cloned over a red stop sign that distractingly
peeked through the trees, but that's about as far as I'll go.

[Robert Coe]

On Sat, 23 Mar 2013 21:37:10 -0400, PeterN <peter.n...@verizon.net>
wrote:

Er... I believe those things in the upper right corner are more like flagpoles
than fountains. Are you sure we're looking at the same picture?

Or are you saying that the boy should go to the point on the patio that's
nearest the upper right corner (and between the flagpoles)? But now there's no
longer a fountain right in front of him, so the fact that he's looking down at
it makes no sense. Or do we just Photoshoppe another fountain in for him to
look at?

What on earth is the point? The picture is perfectly satisfactory with the boy
where he is. It violates no rule of composition, not even the revered Rule of
Thirds.

Hmmm. Looking back, I see a smiley on the original suggestion that I've been
ignoring. I've fallen for a joke, haven't I?

Bob

[Nige Danton]

"dadiOH" <dad...@invalid.com> wrote:
> Alan Browne wrote:
>> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/
>
> Those are nothing short of EXCELLENT!!

They are brilliant aren't they. Can anyone offer recommendations for a
guide (online or a book) as an introduction to the techniques and kit for
this type of photography? Currently have a D7000 and an 18-105 lens.

--
Nige Danton - Replace the obvious with g.m.a.i.l

[Tony Cooper]

On Sun, 24 Mar 2013 05:45:20 +0000 (UTC), Nige Danton
<nige....@nospam.com> wrote:

>"dadiOH" <dad...@invalid.com> wrote:
>> Alan Browne wrote:
>>> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/
>>
>> Those are nothing short of EXCELLENT!!
>
>They are brilliant aren't they. Can anyone offer recommendations for a
>guide (online or a book) as an introduction to the techniques and kit for
>this type of photography? Currently have a D7000 and an 18-105 lens.

I suggest you go to Digital Grin (www.dgrin.com) and follow the forum
on Macros. You'll see the good and the bad, and a lot of tips and
information. Check for new posting frequently.

Pay special attention to the contributions by "Lord Vetinari" and
follow the links to his website. There's no better macro shooting and
teacher around than Brian.

[PeterN]

Horses for courses

--
PeterN

[PeterN]

Nope. I was serious. I have no compunctions about manipulating any
image, if I think the image will be stronger.

--
PeterN

[PeterN]

On 3/24/2013 1:45 AM, Nige Danton wrote:
> "dadiOH" <dad...@invalid.com> wrote:
>> Alan Browne wrote:
>>> http://memolition.com/2013/03/15/the-very-best-of-macro-photography-27-pictures/
>>
>> Those are nothing short of EXCELLENT!!
>
> They are brilliant aren't they. Can anyone offer recommendations for a
> guide (online or a book) as an introduction to the techniques and kit for
> this type of photography? Currently have a D7000 and an 18-105 lens.
>

In addition to Tony Cooper's comments, If you put an extension tube on
your lens, you will be able to move closer to the subject. The tradeoff
is that you will have a smaller depth of field, which you can use to
your advantage.


--
PeterN

[Nige Danton]

PeterN <peter.n...@verizon.net> wrote:

> In addition to Tony Cooper's comments, If you put an extension tube on
> your lens, you will be able to move closer to the subject. The tradeoff
> is that you will have a smaller depth of field, which you can use to your advantage.

Great, thanks for the suggestion. I'll have a look and see what's
available. I'll probably be back with more queries.

[Nige Danton]

Thanks very much i'll go and register.

[ruben safir]

On Sun, 24 Mar 2013 16:18:03 -0400, PeterN wrote:


> In addition to Tony Cooper's comments, If you put an extension tube on
> your lens, you will be able to move closer to the subject. The tradeoff
> is that you will have a smaller depth of field, which you can use to
> your advantage.

what is an extention tube?

Ruben
--
The Coin Hangout: http://www.coinhangout.com/home

[R. Mark Clayton]

"ruben safir" <do...@email.me> wrote in message
news:kjr7sp$q5k$7...@reader1.panix.com...

A short piece of tube that goes between the lens and the body and means that
the lens will focus on nearer objects.

[George Kerby]

On 4/7/13 2:40 AM, in article kjr7sp$q5k$7...@reader1.panix.com, "ruben safir"

<do...@email.me> wrote:

> On Sun, 24 Mar 2013 16:18:03 -0400, PeterN wrote:
>
>
>> In addition to Tony Cooper's comments, If you put an extension tube on
>> your lens, you will be able to move closer to the subject. The tradeoff
>> is that you will have a smaller depth of field, which you can use to
>> your advantage.
>
>
> what is an extention tube?
>
> Ruben

Oh, I am so not going there!

Google is your friend...

<http://bit.ly/10HPtYZ>

[ruben safir]

On Sun, 07 Apr 2013 11:46:26 +0100, R. Mark Clayton wrote:

> A short piece of tube that goes between the lens and the body and means
> that the lens will focus on nearer objects.

How does that geometry work? The longer the tube the greater the
magnification? no...

[Alan Browne]

On 2013.04.10 06:06 , ruben safir wrote:
> On Sun, 07 Apr 2013 11:46:26 +0100, R. Mark Clayton wrote:
>
>> A short piece of tube that goes between the lens and the body and means
>> that the lens will focus on nearer objects.
>
> How does that geometry work? The longer the tube the greater the
> magnification? no...

You're moving the focal plane further away so the image is "spread out"
resulting in a smaller area of the scene on the film or sensor. Of
course there is a penalty in the amount of light received (1/r^2) that
follows the increased focal length so exp. times are longer.

eg: 50mm pushed out 50mm (ext. tube length) becomes 100mm

A 50mm f/1.8 lens has an aperture of 27.8mm

So at 100 mm it becomes: 100/27.8 = f/3.6.

(Simply 50/100 * 1/1.8 = 1/3.6
or simpler: double the aperture number).


--
"There were, unfortunately, no great principles on which parties
were divided – politics became a mere struggle for office."
-Sir John A. Macdonald

[Trevor]

"ruben safir" <do...@email.me> wrote in message

news:kk3dj4$sds$5...@reader1.panix.com...

> On Sun, 07 Apr 2013 11:46:26 +0100, R. Mark Clayton wrote:
>
>> A short piece of tube that goes between the lens and the body and means
>> that the lens will focus on nearer objects.
>
> How does that geometry work? The longer the tube the greater the
> magnification? no...

A tube doesn't magnify anything. It does allow you to focus closer however,
which will give you a bigger image at the sensor *if* you move the lens
closer to the object.

Trevor.

[Alan Browne]

Since it changes the focal length (by virtue of moving the lens further
from the focal plane) it certainly does change the magnification.

[Elliott Roper]

In article <yImdneaV19jCqfXM...@giganews.com>, Alan Browne

<alan....@FreelunchVideotron.ca> wrote:

> On 2013.04.11 22:22 , Trevor wrote:

<snip>

> > A tube doesn't magnify anything. It does allow you to focus closer however,
> > which will give you a bigger image at the sensor *if* you move the lens
> > closer to the object.
>
> Since it changes the focal length (by virtue of moving the lens further
> from the focal plane) it certainly does change the magnification.

It looks to me that it is the same thing. With a bit of
misunderstanding thrown in for internet discussion street cred.

When you measure the focal length of a lens you measure the distance
from the focal plane to the 'centre' of the lens when it is focusing
parallel (collimated) rays of light. Adding an extension tube does not
change the focal length, it simply makes it impossible to focus
parallel rays of light. What the tube does achieve is a bit more
distance between the centre of the lens and the focal plane (sensor) to
give wildly diverging rays from extremely close objects a chance to
focus. Of course the image is bigger, you have just shoved the camera's
snout into the subject's face and put all your attention on a single
zit.

So if the focal length definition I made up is right, then so is
Trevor. If the focal length changes every time you focus the little
sniveller, then you have a hollow victory. Ain't Usenet fun?

--
To de-mung my e-mail address:- fsnospam$elliott$$
PGP Fingerprint: 1A96 3CF7 637F 896B C810 E199 7E5C A9E4 8E59 E248

[Alan Browne]

Thank you Elliott for the clear (enough) explanation.

I don't care about victory, but the truth is nice to find from time to
time.

Egged on by your explanation, I found this example on a website:

Quote:
Example: Step 1. Magnification

Let's pick EF50mm f/1.8 II. The table says the closest focus
distance for this lens is 0.45 meters (= ~17.7 inches), and
the maximam magnification is 0.15x. Using the above basic
formula:

x / 50 = 0.15

Solving for x, the derived maximum built-in lens extension is: x =
50 * 0.15 = 7.5mm

If you add Canon's 12mm extension tube to this lens, you will
achieve a maximum total extension of 7.5 + 12 = 19.5mm

Therefore, using a 12mm extension tube with EF50 1.8 II lens,
you can obtain a maximum magnification of:

19.5 / 50 = 0.39

a magnification of 0.39x [Filling the frame with an object of
actual size 58.2mm x 38.7mm]

EndQuote.

Since 0.39x is larger than 0.15x it is clear there is magnification, if
not FL. Added to this is the benefit of getting closer to the subject,
of course.

http://photography-on-the.net/forum/showthread.php?p=104627

[Elliott Roper]

In article <ivmdnfIQdJ7r8fXM...@giganews.com>, Alan Browne

<alan....@FreelunchVideotron.ca> wrote:

> On 2013.04.12 14:54 , Elliott Roper wrote:

<snip>

>
> Egged on by your explanation, I found this example on a website:

<snip>
> http://photography-on-the.net/forum/showthread.php?p=104627

That was an interesting link. The contributors to that thread were all
over the place. The guy that made most sense was the one who threw a
magic ruler into shot. (The ruler from Calumet that also spat out
exposure adjustment)

It's pretty close to my use of tubes. Mine are simple plastic things
with no wires or contacts (Fotodiox Macro Extension Tube Set). Cheap as
chips (without the chips). Slap a stack of 'em between lens and body
and set everything to manual -- a bit tricky for setting aperture with
an EF lens if you don't want it wide open. It kinda works for some
subjects. The folks with super macro lenses and ring flash things are
in a different league, but at least I have money left for booze.

The real fun starts with focus stacking in Photoshop. One day I will
get it right without forking over untold money for a modern version
that does it automagically.

[Alan Browne]

On 2013.04.12 18:40 , Elliott Roper wrote:
> In article <ivmdnfIQdJ7r8fXM...@giganews.com>, Alan Browne
> <alan....@FreelunchVideotron.ca> wrote:
>
>> On 2013.04.12 14:54 , Elliott Roper wrote:
> <snip>
>>
>> Egged on by your explanation, I found this example on a website:
> <snip>
>> http://photography-on-the.net/forum/showthread.php?p=104627
>
> That was an interesting link. The contributors to that thread were all
> over the place. The guy that made most sense was the one who threw a
> magic ruler into shot. (The ruler from Calumet that also spat out
> exposure adjustment)

I noticed that with some admiration. Reminds me of the RZ67 focus
exposure adjustments.

>
> It's pretty close to my use of tubes. Mine are simple plastic things
> with no wires or contacts (Fotodiox Macro Extension Tube Set). Cheap as
> chips (without the chips). Slap a stack of 'em between lens and body
> and set everything to manual -- a bit tricky for setting aperture with
> an EF lens if you don't want it wide open. It kinda works for some
> subjects. The folks with super macro lenses and ring flash things are
> in a different league, but at least I have money left for booze.
>
> The real fun starts with focus stacking in Photoshop. One day I will
> get it right without forking over untold money for a modern version
> that does it automagically.

It ain't that automagically, just less completely manual - though there
may be some plugins ($) that do it better.

[Eric Stevens]

On Fri, 12 Apr 2013 12:20:47 -0400, Alan Browne
<alan....@FreelunchVideotron.ca> wrote:

>On 2013.04.11 22:22 , Trevor wrote:
>> "ruben safir" <do...@email.me> wrote in message
>> news:kk3dj4$sds$5...@reader1.panix.com...
>>> On Sun, 07 Apr 2013 11:46:26 +0100, R. Mark Clayton wrote:
>>>
>>>> A short piece of tube that goes between the lens and the body and means
>>>> that the lens will focus on nearer objects.
>>>
>>> How does that geometry work? The longer the tube the greater the
>>> magnification? no...
>>
>> A tube doesn't magnify anything. It does allow you to focus closer however,
>> which will give you a bigger image at the sensor *if* you move the lens
>> closer to the object.
>
>Since it changes the focal length (by virtue of moving the lens further
>from the focal plane) it certainly does change the magnification.

Umm - what is changed is not the focal length but the image distance.
The focal length is the image distance when the lens is focused at
infinity and remains constant.
--

Regards,

Eric Stevens

[Wolfgang Weisselberg]

Alan Browne <alan....@FreelunchVideotron.ca> wrote:
> On 2013.04.10 06:06 , ruben safir wrote:

>> How does that geometry work? The longer the tube the greater the
>> magnification? no...

> You're moving the focal plane further away so the image is "spread out"
> resulting in a smaller area of the scene on the film or sensor. Of
> course there is a penalty in the amount of light received (1/r^2) that
> follows the increased focal length so exp. times are longer.

> eg: 50mm pushed out 50mm (ext. tube length) becomes 100mm

> A 50mm f/1.8 lens has an aperture of 27.8mm

> So at 100 mm it becomes: 100/27.8 = f/3.6.

Actually, it's worse. That calculation of yours is only 100%
true for infinite distances (and close at longer distances).

An extension tube means you're getting really close ... as
otherwise you can't focus. Then the effective aperture is
smaller (depending on the magnification).

Similar with the crop factor: it's only true for long distances;
at close distances the crop factor fades away.

At least that's how I understand it.

-Wolfgang

[Alan Browne]

Sorted out about 6 hours before you posted.

[Eric Stevens]

On Sat, 13 Apr 2013 12:38:15 -0400, Alan Browne

<alan....@FreelunchVideotron.ca> wrote:

>On 2013.04.12 20:04 , Eric Stevens wrote:
>> On Fri, 12 Apr 2013 12:20:47 -0400, Alan Browne
>> <alan....@FreelunchVideotron.ca> wrote:
>>
>>> On 2013.04.11 22:22 , Trevor wrote:
>>>> "ruben safir" <do...@email.me> wrote in message
>>>> news:kk3dj4$sds$5...@reader1.panix.com...
>>>>> On Sun, 07 Apr 2013 11:46:26 +0100, R. Mark Clayton wrote:
>>>>>
>>>>>> A short piece of tube that goes between the lens and the body and means
>>>>>> that the lens will focus on nearer objects.
>>>>>
>>>>> How does that geometry work? The longer the tube the greater the
>>>>> magnification? no...
>>>>
>>>> A tube doesn't magnify anything. It does allow you to focus closer however,
>>>> which will give you a bigger image at the sensor *if* you move the lens
>>>> closer to the object.
>>>
>>> Since it changes the focal length (by virtue of moving the lens further
>>>from the focal plane) it certainly does change the magnification.
>>
>> Umm - what is changed is not the focal length but the image distance.
>> The focal length is the image distance when the lens is focused at
>> infinity and remains constant.
>
>Sorted out about 6 hours before you posted.

So I now see.
--

Regards,

Eric Stevens

[ruben safir]

I don't :( How can focal length not change when your adding physical
space.

[ruben safir]

If this is correct:

The focal length of an optical system is a measure of how
strongly the system converges or diverges light. For an
optical system in air, it is the distance over which
initially collimated rays are brought to a focus. A system
with a shorter focal length has greater optical power than
one with a long focal length; that is, it bends the rays
more strongly, bringing them to a focus in a shorter
distance.

from wikipedia. It would seem that a smaller focal lenght would give
higher magnification. So I'm confused.


Ruben

[ruben safir]

On Fri, 12 Apr 2013 16:20:06 -0400, Alan Browne wrote:

> Using the above basic
> formula:
>
> x / 50 = 0.15

what is this formulea (aside from a basic ratio and propoirtion problem)


Ruuben

[ruben safir]

On Sat, 13 Apr 2013 12:04:06 +1200, Eric Stevens wrote:

> The focal length is the image distance when the lens is focused at
> infinity and remains constant.

parrellel rays is not focused on infinity

[Eric Stevens]

On Fri, 19 Apr 2013 23:17:10 +0000 (UTC), ruben safir <do...@email.me>
wrote:

Focal length is defined as the distance behind the lens at which an
image at infinite distance is focussed. This is a an invariant
characteristic of the lens and does not change (unless its a zoom).
This is assigned the symbol 'F'.

Most people take photographs of objects at distances less than
infinity. The distance from the lens to the object is known as the
object distance. Call this 'A'.

The distance at which the image of the object is focussed behind the
lens is known as the image distance. Call this 'B'. This is always
larger than 'F'.

The image and object distances, and the focal length are related by
the equation:

1 1 1
- = - + -
F A B

If you are adding physical space, you are adding it to 'B' i.e. you
are moving the lens out and making 'B' larger. It follows from the
equation that you are making 'A' smaller at the same time i.e. you
obtain focus when the lens is closer to the object. But the point is
'F' does not change.
--

Regards,

Eric Stevens

[Eric Stevens]

On Fri, 19 Apr 2013 23:40:57 +0000 (UTC), ruben safir <do...@email.me>
wrote:

>On Sat, 13 Apr 2013 12:04:06 +1200, Eric Stevens wrote:
>
>> The focal length is the image distance when the lens is focused at
>> infinity and remains constant.
>
>
>parrellel rays is not focused on infinity

Correct.

Parallel rays are generated by an object at infinity. When you focus a
lens at an object at infinity the rays from that object to the lens
are parallel (until they hit the lens).
--

Regards,

Eric Stevens

[ruben safir]

On Sat, 20 Apr 2013 21:19:10 +1200, Eric Stevens wrote:

> This is a an invariant characteristic of the lens and does not change
> (unless its a zoom).

How does a zoom do this?

[ruben safir]

On Sat, 20 Apr 2013 21:19:10 +1200, Eric Stevens wrote:

> The distance at which the image of the object is focussed behind the
> lens is known as the image distance. Call this 'B'. This is always
> larger than 'F'.

Thanks

I'm struggling with the terminalogy.

Please define "bind the lens". Is that the optical image projected on
the sensor?

Ruben

[ruben safir]

On Sat, 20 Apr 2013 21:21:31 +1200, Eric Stevens wrote:

>>parrellel rays is not focused on infinity
>
> Correct.
>
> Parallel rays are generated by an object at infinity. When you focus a
> lens at an object at infinity the rays from that object to the lens are
> parallel (until they hit the lens).

How is that possible? An object 6 feet wide focused at inifinity can not
produce parallel light on the lens, otherwise the light would be too wide
to fit on the lens (and a pinhole camera would never work).

[Eric Stevens]

On Sun, 21 Apr 2013 22:26:57 +0000 (UTC), ruben safir <do...@email.me>
wrote:

>On Sat, 20 Apr 2013 21:19:10 +1200, Eric Stevens wrote:
>
>> This is a an invariant characteristic of the lens and does not change
>> (unless its a zoom).
>
>
>How does a zoom do this?

It's complicated. It does it by moving around internal components of a
complex lens assembly. I won't try and explain it but you might be
interested in looking at
http://graphics.stanford.edu/courses/cs178-10/applets/zoom.html
--

Regards,

Eric Stevens

[Eric Stevens]

On Sun, 21 Apr 2013 22:34:06 +0000 (UTC), ruben safir <do...@email.me>
wrote:

>On Sat, 20 Apr 2013 21:19:10 +1200, Eric Stevens wrote:
>
>> The distance at which the image of the object is focussed behind the
>> lens is known as the image distance. Call this 'B'. This is always
>> larger than 'F'.
>
>
>Thanks
>
>I'm struggling with the terminalogy.
>
>Please define "bind the lens". Is that the optical image projected on
>the sensor?
>

I can't help you with that one. I didn't write it and I can't find
where it was used. Can you explain further?
--

Regards,

Eric Stevens

[Eric Stevens]

On Sun, 21 Apr 2013 22:57:07 +0000 (UTC), ruben safir <do...@email.me>
wrote:

It would if the 6 feet wide object was an infinite distance away.
--

Regards,

Eric Stevens

[Trevor]

"Eric Stevens" <eric.s...@sum.co.nz> wrote in message
news:ie99n8tj0prr9so3l...@4ax.com...

> On Sun, 21 Apr 2013 22:57:07 +0000 (UTC), ruben safir <do...@email.me>

>>On Sat, 20 Apr 2013 21:21:31 +1200, Eric Stevens wrote:
>>>>parrellel rays is not focused on infinity
>>>
>>> Correct.
>>>
>>> Parallel rays are generated by an object at infinity. When you focus a
>>> lens at an object at infinity the rays from that object to the lens are
>>> parallel (until they hit the lens).
>>
>>How is that possible? An object 6 feet wide focused at inifinity can not
>>produce parallel light on the lens, otherwise the light would be too wide
>>to fit on the lens (and a pinhole camera would never work).
>
> It would if the 6 feet wide object was an infinite distance away.

Actually no, the light would be warped by the gravitational field of every
star system between the object and the lens! :-)

Trevor.

[Eric Stevens]

If you want to complicate matters even further, you should consider
the effects of 'dark matter'. :-(>
--

Regards,

Eric Stevens

[Wally]

On Sun, 21 Apr 2013 22:57:07 +0000 (UTC), ruben safir <do...@email.me>
wrote:

The rays are not parallel, but are nearly so... and behave effectively
like parallel rays when they hit the lens.

Here is a little math exercise for you: calculate the difference in
angle for the rays hitting the top and bottom of the lens. (Make
assumptions as necessary.)

W

[PeterN]

If you want to get theoretical, the gravitational influence of randomly
distributed objects might very well equalize each other. Therefore the
rays would remain parallel.
But, I think the notion of absolutely parallel lines wound run counter
the the theory of relativity.



--
PeterN

[Wolfgang Weisselberg]

ruben safir <do...@email.me> wrote:
> On Sat, 20 Apr 2013 21:21:31 +1200, Eric Stevens wrote:

>>>parrellel rays is not focused on infinity

>> Correct.

>> Parallel rays are generated by an object at infinity. When you focus a
>> lens at an object at infinity the rays from that object to the lens are
>> parallel (until they hit the lens).

> How is that possible? An object 6 feet wide focused at inifinity can not
> produce parallel light on the lens,

Of course it can. Since the view angle of the lens is greater
than zero, the object will record only at a single location.

Hint: Stars are much, much larger than our planet Earth, yet
they come as single dots. And they're not even infinitely
far away. But their rays are *very* *very* *very* close to
perfectly parallel when recorded by your lens.

> otherwise the light would be too wide
> to fit on the lens (and a pinhole camera would never work).

You only need an object-space telecentric lens. Which camera
lenses aren't.

-Wolfgang

[Wolfgang Weisselberg]

ruben safir <do...@email.me> wrote:
> On Sat, 20 Apr 2013 21:19:10 +1200, Eric Stevens wrote:

>> This is a an invariant characteristic of the lens and does not change
>> (unless its a zoom).

> How does a zoom do this?

By moving the center element of a Cooke triplet.

Of course that's only the first tiny step. You need to
replace the 3 lenses with other lens groups, but the basic
idea remains ...

http://www.lensrentals.com/blog/2011/09/lens-genealogy-part-2

-Wolfgang

[Wolfgang Weisselberg]

PeterN <peter.n...@verizon.net> wrote:
> On 4/22/2013 1:46 AM, Trevor wrote:

>> Actually no, the light would be warped by the gravitational field of every
>> star system between the object and the lens! :-)

> If you want to get theoretical, the gravitational influence of randomly
> distributed objects might very well equalize each other. Therefore the
> rays would remain parallel.

Actually, nope. It's the same as adding multiple random noise to
a signal or a random walk from a point.

-Wolfgang

[PeterN]

vielleicht etwas zu tun <> etwas tun

--
PeterN

[Wolfgang Weisselberg]

PeterN <peter.n...@verizon.net> wrote:
> On 4/29/2013 8:57 AM, Wolfgang Weisselberg wrote:
>> PeterN <peter.n...@verizon.net> wrote:
>>> On 4/22/2013 1:46 AM, Trevor wrote:

>>>> Actually no, the light would be warped by the gravitational field of every
>>>> star system between the object and the lens! :-)

>>> If you want to get theoretical, the gravitational influence of randomly
>>> distributed objects might very well equalize each other. Therefore the
>>> rays would remain parallel.

>> Actually, nope. It's the same as adding multiple random noise to
>> a signal or a random walk from a point.

> vielleicht etwas zu tun <> etwas tun

True but irrelevant.

Getting theoretical: The theory how random influences add is
well established. That they equalize each other is about as
likely as that they completely add to each other, i.e. both
bowing the light in the identical direction. That's both not
"might very well", unless you "might very well" win a million
dollars in the lottery ten times in a row. So I bow to your
immense luck and admit I was wrong.

-Wolfgang

[PeterN]

Ah! but are the gravitational fields random. According to Einstein, they
are not.


--
PeterN

[Wolfgang Weisselberg]

So you're basically saying that the gravitational fields are
ordered in such a way that photons from any random source stay
parallel, at least in a sizeable number of cases.

I'd like a single geometry designed by you where a bundle
of parallel light rays from a single direction are bend by
gravity sources in such a way that they remain exactly parallel.
You can freely place the gravity sources.

Kindly remember that any single gravity source will affect such
a bundle of exactly parallel rays differently, depending on the
mass of the gravity source and the (different!) distance from
the individual ray to the gravity source. In other words:
a bunch of parallel rays *will* be spread when it passes a
gravity source ...

Too hard?

-Wolfgang

[PeterN]

I I precisely understood how gravitational forces interact, I doubt I
would waste time responding to you.

--
PeterN

[Martin Brown]

Trouble is that stars for the most part tend to be heavily concentrated
in galaxies, cluster of galaxies and super clusters of clusters.

The net result is that you can get strong lensing effects of very
distant sources by galaxies or clusters between us and the source.
Einstein rings were predicted long before they were observed.

http://hubblesite.org/hubble_discoveries/science_year_in_review/pdf/2006/einstein_rings_natures_gravitational_lenses.pdf

Probably by far the prettiest one is the Hubble image of the horseshoe
ring around LRG 3-757 (sorry about the unromantic name for the latter)

http://nasa-image.blogspot.co.uk/2011/12/horseshoe-einstein-ring-from-hubble.html

That said most of the light rays from distant sources to an exceedingly
good approximation do remain parallel.

--
Regards,
Martin Brown

[J. Clarke]

In article <ki5src$6sp$1...@speranza.aioe.org>, tre...@home.net says...
>
> "Rob" <mesa...@google.com> wrote in message
> news:ki3hva$acq$1...@dont-email.me...
> >>> Curious why you say they would NOT do well in a camera club? Just
> >>> wondering?
> >>
> >> Many judges would say: the hot spots are distracting; parts of the
> >> creatures are outside the image area, etc.
> >> Please note the above is not my impression, but is intended to be a
> >> commentary of the weaknesses of camera club judging. I have often said
> >> that Cartier-Bresson, would not do well in camera club competitions.
> >>
> > Agree with your comments, camera club judges are full of themselves on the
> > night, nit picking, they can't correctly evaluate the elements of an image
> > and ridicule the content. As an example some time ago had a image
> > evaluated and the comment was the horizon was not straight, funny about
> > that it had lens curvature. Another example was architecture, where
> > verticals should be vertical or over over emphasised, looking up at a tall
> > building, the judge picked on one as not vertical which should have been,
> > but there were 2 others out of whack as well, but no criticism of the fact
> > but given awards!
> >
> > I have even pointed out plagiarism of images and part images, to the
> > committee, ripped off the web, and they have condoned the use of such
> > images, to the extent where the image has been best in section. I was
> > being a pain in the arse to them.
> >
> > I'm sure other images being presented in competitions, were not setup or
> > photographed by the author, as they didn't show a consistent standard of
> > such photographer compare with there other submissions.
> >
> > What does amaze me is the judges will critique an image but can't explain
> > why or give their opinion how to rectify the perceived fault.
> >
> > One particular night there was this judge who insisted using "Um" all the
> > time, this irritates me as its them catching up with their thoughts,
> > anyhow this was so annoying that I started to count the number of time she
> > used "Um" and the intervals between. Results basically, 700, at 20 second
> > intervals, yep - over 3 hour period.
> > What a long boring night that turned out to be.
> >
> > Camera clubs live in there own little world and stay in a rut.
>
>
> The real question is why you would bother then rather than get out and take
> pictures for your own pleasure, and/or paying clients, rather than approval
> from stupid camera club judges?

It's not a matter of "approval", it's a matter of soliciting the advice
of others to improve your own work. You're not obligated to take that
advice, but having it can be helpful.

[PeterN]

Spot on. Many photographic masterpieces, would not score well in CC
competitions. There are members who prepare images solely for CC
competitions. If that is what they want, than I say fine, but as you
correctly point out, there's a lot more to camera clubs than just
competitions. Here is an image that I like, but did not do well in CC
competition. But, I still like it.

<https://dl.dropboxusercontent.com/u/97242118/swooper.jpg>

--
PeterN

[Wolfgang Weisselberg]

And that *keeps* the rays *parallel*?

> The net result is that you can get strong lensing effects of very
> distant sources by galaxies or clusters between us and the source.
> Einstein rings were predicted long before they were observed.

> http://hubblesite.org/hubble_discoveries/science_year_in_review/pdf/2006/einstein_rings_natures_gravitational_lenses.pdf

Yep, but the rays aren't parallel --- can't be, otherwise
they must look like they came from the very same point (due
to the distances involved).

> That said most of the light rays from distant sources to an exceedingly
> good approximation do remain parallel.

Only for distances that are very short compared to the distance
from where they come.

But we were getting theoretical, not real-world 'close enough'.

-Wolfgang

[Wolfgang Weisselberg]

PeterN <peter.n...@verizon.net> wrote:
> On 5/6/2013 2:40 PM, Wolfgang Weisselberg wrote:

[...]

>>>>>> PeterN <peter.n...@verizon.net> wrote:

>>>>>>> If you want to get theoretical, the gravitational influence of randomly
>>>>>>> distributed objects might very well equalize each other. Therefore the
>>>>>>> rays would remain parallel.

[...]

>> So you're basically saying that the gravitational fields are
>> ordered in such a way that photons from any random source stay
>> parallel, at least in a sizeable number of cases.

>> I'd like a single geometry designed by you where a bundle
>> of parallel light rays from a single direction are bend by
>> gravity sources in such a way that they remain exactly parallel.
>> You can freely place the gravity sources.

>> Kindly remember that any single gravity source will affect such
>> a bundle of exactly parallel rays differently, depending on the
>> mass of the gravity source and the (different!) distance from
>> the individual ray to the gravity source. In other words:
>> a bunch of parallel rays *will* be spread when it passes a
>> gravity source ...

>> Too hard?

> I I precisely understood how gravitational forces interact, I doubt I
> would waste time responding to you.

If you precisely understood how gravitational forces
(and matter and space) interacts, you'd probably on the list
for the Nobel price.

If you "merely"[1] had a working understanding of how
gravitatonal forces act *and what that means* you'd be more
careful about "in such a way that photons from any random
source stay parallel", e.g. by making clear that they probably
won't stay perfectly parallel. ('probably' only because I
cannot guarantee that there can't be a setup where they *do*
stay parallel.)

-Wolfgang

[1] not that that is something small in any way

[PeterN]

But the origins of the gravitational are not random. You certainly are
free to speculate what would happen if they were, but I would rather
concentrate on the far less esoteric topic, of how to improve my images.

--
PeterN

[Wolfgang Weisselberg]

PeterN <peter.n...@verizon.net> wrote:
>>>>>>>> PeterN <peter.n...@verizon.net> wrote:

>>>>>>>>> If you want to get theoretical, the gravitational influence of randomly
>>>>>>>>> distributed objects might very well equalize each other. Therefore the
>>>>>>>>> rays would remain parallel.
[...]

> But the origins of the gravitational are not random. You certainly are
> free to speculate what would happen if they were, but I would rather
> concentrate on the far less esoteric topic, of how to improve my images.

Did I get that right? You're basically saying that the
objects are both random and not random?

-Wolfgang

[PeterN]

Np Read carefully


--
PeterN