I have some questions...
Tina L. Green
2. A 300mm telephoto lens brings the object ______
times closer.
3. If your camera meter says that the correct exposure is 1/60 sec @ f16,
what would the effect on exposure be if you shot the picture at 1/125 @ f11?
4. All pics on a roll of film were overexposed. If the negatives were
overexposed by three stops and the ISO/ASA film speed dial was set wrong. It
should have been on 400 but it was set on another film speed. Can you tell
me what was the dial set and how do I know?
Thanks a bunch--these questions have me stumped!!!
Tina
news.ntlworld.com
"Tina L. Green" <ptb0...@mail.wvnet.edu> wrote in message
news:3def...@alpha.wvnet.edu...
> 1. Are wide angle lens great for head and shoulders portrait shots? yes
& no YES for a strange & intersting look OR no coz the background is still
gona be sharpish,,, the other thing is that the person is going to be
boss-eyed OR just have a not good look on thare face) just experement i gues
!. A 70MM to 135MM is perfect !
>
> 2. A 300mm telephoto lens brings the object 6 TIMES (well a 500MM is
10 TIMES closer)
> times closer.
>
> 3. If your camera meter says that the correct exposure is 1/60 sec @
f16,
> what would the effect on exposure be if you shot the picture at 1/125 @
>
> 4. All pics on a roll of film were overexposed. If the negatives were
> overexposed by three stops and the ISO/ASA film speed dial was set wrong.
It
> should have been on 400 but it was set on another film speed. Can you tell
OVEREXPOSURE means that the film has too much light & is all WEAK - so the
ISO (NOT ASA coz ASA is the american equivelent) must have been below the
films setting !.
>
> Thanks a bunch--these questions have me stumped!!!
> Tina
>
>
Just keep the passion for it & stick to it NO MATTER WOT the cost/money !
coz i have started a collage course & have been doing photography since 1997
& have not lost the passion for it !
BUT I HOPE THIS NEVER HAPPENS to u !
Al Denelsbeck
> 1. Are wide angle lens great for head and shoulders portrait shots?
No. The wider the angle, the more the lens acts like a Christmas
ornament, causing closer subjects to take up more of the frame, while more
distant subjects become reduced. This will result in large noses and small
shoulders. Also, wides have greater depth-of-field, meaning more of your
background can be in sharp focus at all but the smallest f-stops (like
f2.8), and thus the background has more opportunity to blend with your
subject, or be too distracting by being sharp. You can sometimes get
'acceptable' results while using not too wide an angle, but it's not the
best style lens to use.
Best is a short telephoto, somewhere around 80-120mm (for 35mm film),
for two reasons. The first is that it renders faces in the most pleasing
aspects, keeping noses proportional to ears and such. The second is that it
handles depth of field much better at most popular f-stops (from f2.8
through f22), allowing the entire face to be in focus but not the
background, so the subject stands out.
> 2. A 300mm telephoto lens brings the object ______
> times closer.
Um, than what?
For 35mm film, 50mm is considered 'normal', or closest to what our eyes
see and least distortive of the frame. Every 50mm added means about another
1x of magnification. So for 35mm film, 300mm means about a 6x magnification.
For APS, normal is closer to 40mm, so 300mm focal length is about 7.5x. For
digital, you have to know the size of the image area. Take the diagonal
measurement, add about 15% for overlap, and you have your 'normal'
magnification.
> 3. If your camera meter says that the correct exposure is 1/60 sec @
f16,
> what would the effect on exposure be if you shot the picture at 1/125 @
f11?
>
> 4. All pics on a roll of film were overexposed. If the negatives were
> overexposed by three stops and the ISO/ASA film speed dial was set wrong.
It
> should have been on 400 but it was set on another film speed. Can you tell
> me what was the dial set and how do I know?
Reciprocity! I'm gonna get a little long here, but this is valuable
information, and answers both questions.
Each numer on your camera relates to the other. It's the reason they're
so weird. For both shutter speed and film speeds, 'one stop' (or one EV)
change means the number either doubles or halves. For apertures, doubling or
halving the *number itself* results in *two stops* difference.
So, 1/60 to 1/1/25 on your shutter is one stop less (less time, so less
light). 1/250 is *two* stops less light than 1/60 (doubles, then doubled
again). 200 speed film is one stop faster than 100 speed (and needs less
light), 400 speed is two stops faster.
But apertures are slightly funky, and there's a reason for it. So f8 is
*two* stops less than f4 (smaller opening, less light). One stop is f4 to
f5.6. They don't quite match up right, due to areas of a circle and not
wanting to put more decimal places on your camera dials, so just get close.
Anything in between these measurements are half-stops, or occasionally
you can even get 1/3 stops on your camera (for instance, 400 film speed down
to 320 is 1/3 stop slower).
So, change any camera setting one stop, then change any other one stop
in the opposite direction, gives the exact same exposure. 1/125 at f8 is the
same exposure as 1/60 at f11 (one stop more shutter, one stop less aperture,
they even up).
So for question three, you have decreased shutter speed one stop
(faster, less light), but increased the aperture opening one stop (more
light), so there's no change.
For question 4, you need to know what constitutes 3 stops more light
than 400 speed film. If you overexposed, that means the camera thought the
film was slower (less sensitive to light). So you halve the film speed three
times, and get 50 speed. That's what the camera was set at.
I mentioned the reason for apertures being two stops per half/double, so
I'll cover that briefly. Apertures are actually just the back portion
(denominator, if you care) of a fraction, and the fraction relates to focal
length. So f4 is actually 1/4 of the focal length in the diameter of the
opening. And thus f16 is 1/16th. Ah, now you know why the bigger number
actually means less light! It's not really bigger, it's smaller.
But, if you double the diameter, you increase *area* of the opening by
four times. Easiest way to think of this is to use a square opening. A
square measuring one inch on each side is one square inch in area. But if
you add an inch to the width and to the height, doubling both (which also
doubles the diagonal measurement, closest to our diameter of an aperture),
you now have *four* square inches. That's why apertures change two stops
when halving/doubling their f-number.
Now you have not only the answers, but the ability to adjust your
exposure as needed from any given reference point, and change depth-of-field
to suit yourself, or increase shutter speed without making the pic too dark.
Most valuable thing to know about photography. As I said, that's called
'Reciprocity'.
Drop me a line, and I'll tell you where to send the check :-).
- Al.
--
Remove 'block' for direct reply.
Online photo gallery at www.wading-in.net
zeitgeist
> 1. Are wide angle lens great for head and shoulders portrait shots?
wide angle lenses would make the nose appear much larger, the ears smaller,
not at all flattering.
>
> 2. A 300mm telephoto lens brings the object ______
> times closer.
closer than what? than a 50mm lens? , I'd guess six time closer.
>
> 3. If your camera meter says that the correct exposure is 1/60 sec @
f16,
> what would the effect on exposure be if you shot the picture at 1/125 @
f11?
now come on, you can figure this one out, each step doubles or halves the
exposure, the second cancels the two changes out.
>
> 4. All pics on a roll of film were overexposed. If the negatives were
> overexposed by three stops and the ISO/ASA film speed dial was set wrong.
It
> should have been on 400 but it was set on another film speed. Can you tell
> me what was the dial set and how do I know?
>
each stop doubles the exposure, ISO doubles or halves each step. 3 stops,
400, 800 1600, oops wrong way. 400, 200 100, 50
of course film maxes out at three stops so it could be six stops or five as
well as three.
EricR
good image is subjective.
>times closer.
know what the formula is.
>3. If your camera meter says that the correct exposure is 1/60 sec @ f16,
>what would the effect on exposure be if you shot the picture at 1/125 @ f11?
As shutter speed increases so Aperture needs to (Numerically)
decrease, and vice versa. If I tell you the normal steps on a shutter
effectively reduce the previous speed by half, i.e. 1/60th allows half
the light that 1/30th does. Now baring that in mind, and the first
point I said, can you work out what aperture does? i.e f16 to f11
allows_______ light int the lens.
>4. All pics on a roll of film were overexposed. If the negatives were
>overexposed by three stops and the ISO/ASA film speed dial was set wrong. It
>should have been on 400 but it was set on another film speed. Can you tell
>me what was the dial set and how do I know?
How do you know they were overexposed by __3__ stops? If you knwo that
then you can calculate the ASA that was set on your camera. It works
the same as the shutter/aperture thing above.
50 = 3
100 = 2
200 = 1
400 = 0
800 = -1
1600 = -2
3200 = -3
I know I haven't answered directly, but you'll get more benefit from
learning the relationship between shutter and aperture.
"Give a man a fish and he will eat for a day. Teach a man to fish, and
he will smell of fish for a lifetime!
EricR
--
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Jim V
Answer to 1: A PORTRAIT LENS should be between 85mm and 120 mm to avoid distortion.
karl
a blurb to the exceptional answers that were given re: Question #3
1) you need to consider if what you are photographing is in motion or
not, and how steady your hand is. As you probably know, the longer the
lense stays open the more blur you get. If you are going to speeds
slower than 1/60 chances are you will need a tripod, and if you are
photographing action, you will need a quicker & bigger opening to let
enough light in and not get a blur (unless of course that is what you
are after)
2) There is a term that perhaps you know, called depth of field. If the
amount of depth you want in the picture is important, then you would
want to use a smaller aperature. Maybe somebody out there more
experienced than myself can tell you how to calculate that, I just go by
feel.
3) Most telephoto lenses are clearest/sharpest at a particular f-stop,
and you need to find out what that is for your lense. I understand, and
somebody please correct me if I am wrong, most will be in the f/11 area.
Hope that helps.
karl
Rob Walls
are not good for portraits.
I disagree. It depends on the distance you are from your subject and what
you have to say about the subject.
For example Arnold Newman's portrait of Igor Stravinsky, (you can view it
here: http://www.jacobsonbest.com/arnold_newman_1.htm) though shot on large
format is almost certainly taken with a wide-angle lens.
My favourite portrait lens is a 35mm medium wide-angle which is the ideal
lens for what I call "environmental portraits"...pictures of people within
their surroundings. Shooting with this lens at any distance over a metre you
will not get noticeable distortion.
--
Rob Walls
http://home.iprimus.com.au/rwalls
http://www.profotos.com/pros/profiles/index.cfm?member=82
Ozimages portfolio: http://www.ozimages.com.au/portfolio.asp?MemberID=47
"karl" <white...@telus.net> wrote in message
news:3DFAD38D...@telus.net...
John Garrison
"Rob Walls" <rwa...@iprimus.com.au> wrote in message
news:3e2e2...@news.iprimus.com.au...
No doubt the Stravinsky portrait is superb, and likewise taken with a short
lens. Perhaps the hesitency to use short lenses has to do with the kind of
portaits we are taking......the kind that puts the subject well into the
shot, and the background well hidden and what there is quite blurred with
short DOF. For this type a long lens is best. Few of us maybe would have the
particular kind of creativity to come up with another Stravinsky. I wouldn't
have I am sure. But now I know it can be done, and look good, at least.