4 pictures on 1 4x5 sheet - Hole cut in dark slide?
Mike Jordan
been for what I'm thinking of doing.
Anyway, I was wondering if 4 pictures could be taken on one sheet of
4x5 film using two dark slides with a square cut out of a corner.
Put the slide in, take one picture exposing the top left side. Flip
the dark slide and take a picture of the lower left side. Put the
other slide in and take a picture of the top right side. Flip it and
take a picture of the lower right side.
The reason I'm thinking of doing this is to test my 4x5 lens and
shutter. I want to take 4 pictures and bracket the fstops to see
how accurate it is. I know I could use 4 sheets of film, but I
would like to develop one sheet and know that the developing time,
temp and other variables are the consistent. Then I can contact
print it at one time.
If 4 makes it kind of hard, would splitting the slide in half work
better?
Just wondering as I'm sitting here thinking of projects to do this
winter when I don't want to lug my cameras out in the rain.
Mike
--
Hillsboro, Oregon
Bouvier des Flandres - Herding & Working Dogs
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Jean-David Beyer
>
> I think I've seen it talked about in here, but it might not have
> been for what I'm thinking of doing.
>
> Anyway, I was wondering if 4 pictures could be taken on one sheet of
> 4x5 film using two dark slides with a square cut out of a corner.
> Put the slide in, take one picture exposing the top left side. Flip
> the dark slide and take a picture of the lower left side. Put the
> other slide in and take a picture of the top right side. Flip it and
> take a picture of the lower right side.
>
> The reason I'm thinking of doing this is to test my 4x5 lens and
> shutter. I want to take 4 pictures and bracket the fstops to see
> how accurate it is. I know I could use 4 sheets of film, but I
> would like to develop one sheet and know that the developing time,
> temp and other variables are the consistent. Then I can contact
> print it at one time.
>
> If 4 makes it kind of hard, would splitting the slide in half work
> better?
>
> Just wondering as I'm sitting here thinking of projects to do this
> winter when I don't want to lug my cameras out in the rain.
>
in the back that could be used for this, using ordinary dark slides. It
is really tough to remember how to move them so as to get 4 exposures on
a single sheet, though it certainly could be done if you wanted to do it
on a regular basis. If I did, though, I would just have used my roll
film holder and shot 120 or 220 film instead.
When I was doing a lot of film testing, I just measured how far the dark
slide had to extend to expose 1/2 the sheet with a machinist's square,
Then I could give x and 2x exposure by pulling the slide out 1/2 way and
giving an exposure and then pulling it all the way out and giving it an
identical exposure. While this does not allow for intermittancy effect,
it is good enough for routine film testing and you need not mess up a
dark slide.
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Ryan
dark slide cut in half that I use for getting two panoramic size
negatives (2"x5") on one sheet of film. It works well, but requires
some careful thought for composition and rembering the sequence.
I made some fine pencil marks on the ground glass to aid with
composition. You could do the same. Just more tricky that's all.
R.
On Sat, 20 Oct 2001 15:23:00 -0700, Mike Jordan <mjo...@europa.com>
wrote:
John Yeo
film. It is a sure fire way to KILL the light traps in the holder. the
light traps are made up of a few pieces of spring metal with felt glued on.
The spring metal is pointed downwards, toward the bottom of the holder, and
allows the slides to be inserted in one direction only. When you pull the
slide out, the edge gets caught on the spring metal and screws it up. I
eventually just gave up. Just thinking about it right now, it occured to me
that you could make slides with strips cut out of them lengthwise. That
way, there's no edge to get caught on the light trap.
FWIW, except for the problem with the light traps, the black paper worked
really well for masking out parts of the film. I guess it's called
posterboard. Thicker than regular craft paper, but wouldn't be cardboard.
I got it at the drugstore for $0.69 for a sheet 20"x24" It is much cheaper
than cutting up darkslides.
John
"Mike Jordan" <mjo...@europa.com> wrote in message
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Francis Roy
I have a collection of oddball photo "stuff" which includes a holder an
slides to give 5 images. It is somewhere in the attic/basement/garage
. I can't put my hands on it but I know I have it. I don't think it
was commercially available I think it was a home tinkerer type of
product. Just wanted to let you know it has been done.
Francis in VT
Michael Gudzinowicz
> I think I've seen it talked about in here, but it might not have
> been for what I'm thinking of doing.
>
> Anyway, I was wondering if 4 pictures could be taken on one sheet of
> 4x5 film using two dark slides with a square cut out of a corner.
> Put the slide in, take one picture exposing the top left side. Flip
> the dark slide and take a picture of the lower left side. Put the
> other slide in and take a picture of the top right side. Flip it and
> take a picture of the lower right side.
>
> The reason I'm thinking of doing this is to test my 4x5 lens and
> shutter. I want to take 4 pictures and bracket the fstops to see
> how accurate it is. I know I could use 4 sheets of film, but I
> would like to develop one sheet and know that the developing time,
> temp and other variables are the consistent. Then I can contact
> print it at one time.
>
> If 4 makes it kind of hard, would splitting the slide in half work
> better?
>
> Just wondering as I'm sitting here thinking of projects to do this
> winter when I don't want to lug my cameras out in the rain.
plastic sheet used for term paper binders or posterboard to fit between
the holder and camera back as a mask. Use the holder as a template, and be
sure that the mask does not extend over the ridge next to the film opening
near the dark slide insertion end. Cut a rectangle out of a corner of the
mask, and focus with it in place in front of the GG. After placing the
holder over it the mask, take care not to pull the holder out with the
darkslide since the ridge and groove in the camera back won't keep the
holder in place.
One downside is that you might develop some light leaks at the edges,
but for tests, it probably won't matter. The other problem is that
the test areas are off-axis, and focus on different areas of the
"subject". You can move the camera around, but it might be easier
to set focus at infinity and lock it down, take a meter reading of
a light box or the diffusion head off an enlarger, and push the
lens up against it to get even exposure across the field. You still
will get fall-off towards the corners, but the areas near the lens
axis should be comparable.
Since the f/stops are very likely to be accurate, there are all sorts
of ways to check shutter speeds using a tester, oscilloscope, sound
cards, hifi turntables, TV sets, etc.
Stephe Thayer
>
> Since the f/stops are very likely to be accurate, there are all sorts
> of ways to check shutter speeds using
> hifi turntables, TV sets,
Really? How does that work?
--
Stephe
Michael Gudzinowicz
> Michael Gudzinowicz wrote:
>
> > Since the f/stops are very likely to be accurate, there are all sorts
> > of ways to check shutter speeds using
> > hifi turntables, TV sets,
>
> Really? How does that work?
photograph the arc it makes. At 33 1/3 rpm, each 360 deg revolution takes
60/33.33 = 1.80 sec, or the rate is 200 deg per second. Each degree
corresponds to 5 milliseconds. The light can be moved closer to the center
so multiple exposure tests can be done on one sheet.
TV sets can be used with focal plane shutter cameras such as the Graphlex
and Speed Graphic. Look up the lines per scan, refresh rate and whether
the frames are interlaced or not. Common TVs in the US use 525 lines
interlaced at 60 Hz per frame, or 60 x 262.5 or 30 x 525 = 15750 lines per
second. Each line corresponds to 1/15750 sec = 0.000635 sec. The screen
is photographed with the shutter running horizontally, which gives a
diagonal band on film. The lines are counted to determine speed. If there
are differences between the left and right edges, then curtain travel
times or the fixed Graphic/Graflex slit travel speed varies. With a bit of
experience, one can look through the lensless back of a 35 mm SLR at the
TV screen and set the travel times/tension of older focal plane shutters.
The oscilloscope method is simple. Put a phototransistor in a small black
box with an opening which can be covered by the lens and wire it in series
with a battery, a variable resistor to limit current and the scope leads.
Place the lens over the hole, and illuminate it with a bright light. Set
the scope so it is triggered by a voltage change, and fire the shutter.
The trace will follow the opening and closing of the shutter. The time at
the half-height of the polygon formed by the base, rise, peak and fall is
the average time. Leaf shutter speeds are calibrated wide open, but
exposure time may vary at other f/stops where the rise and fall are
smaller in proportion to the peak time. I use a scope with my leaf lenses.
The geometry (size and placement) has to be optimized for 35 mm use, but
leaf shutters don't present any problems.
Soundcard based testers are described on the web. I haven't used them.
John Yeo
picture looking directly down at it. Develop the negative and make an
enlargement. because the dot is moving, at slower speeds (less than 1/60 or
1/125), it will be a streak in the picture. Use a protractor to measure how
many degrees the dot traveled when the shutter was open.
x / .55 = degrees traveled / 360, where x is how many seconds the shutter
was open. The record player moves at 33 rpm, so that's one revolution
(360 degrees of rotation) every .55 sconds. For focal plane shutters, you
would have to make sure to snap the picture when the dot is moving paralel
to the slit.
I don't remember the specifics of the television method, but it only works
for focal plane shutters. The television refreshes the picture 30 times a
second with a line that moves downward. The focal plane shutter travels
from side to side, so when you take a picture of a television, you end up
with a bunch of diagonal lines. I think you count the number of lines, and
multiply that by 1/30 to figure out how long the shutter was open.
Something like that.
John
"Stephe Thayer" <ms_s...@hotmail.com> wrote in message
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John Yeo
"Stephe Thayer" <ms_s...@hotmail.com> wrote in message
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Argon3
I worked at a catalog studio where we had an extensive collection of these
ingenious devices. Most were for the 8X10 but the configurations were great
and it made bracketing some of the images much more economical. I wonder why
the current manufacturers don't make these split backs for their products. The
use of the panoramic format of 4X10 that has been a recent trend would be an
example. There's no need for a special 4X10 camera and holders - just an 8X10
Dorf with the split back to make two 4X10 exposures on one sheet of 8X10.
argon
Michael Gudzinowicz
> http://www.rit.edu/~andpph/text-shutter.html
Thanks for posting a URL for a page with a more detailed
explanation.
A simple circuit for a soundcard shutter can be found at:
http://www.geocities.com/Yosemite/2131/shspeed.html
The same circuit will work with an oscilloscope, or software converting a
soundcard to a scope. The components may be re-arranged to give the
sequence: 1. on/off switch, 2. battery, 3. 10K resisitor rather than 5K
and 4. phototransistor. In parallel with the phototransistor and 10 K
resistor, add another 10 K resistor and a flash synch connector. Both the
synch and phototransistor can trigger the circuit, and the relative timing
will be apparent in the trace. That permits one to adjust focal plane and
regular flash bulb shutter delays, and check electronic flash settings,
especially at high shutter speeds.
wim wiskerke
Gudzinowicz) wrote:
>Stephe Thayer <ms_s...@hotmail.com> wrote:
>
>> Michael Gudzinowicz wrote:
>> > Since the f/stops are very likely to be accurate, there are all sorts
>> > of ways to check shutter speeds using
>Soundcard based testers are described on the web. I haven't used them.
http://www.geocities.com/Yosemite/2131/shspeed.html
shutterspeedtester - Sebastian Laiblin. How to measure shutter-speed
with your soundcard and a $3-wiring.(Wie man mit einer Soundkarte und
einer 5,-DM-Schaltung Verschlusszeiten misst). In german and english.
http://24.0.232.44/cunningham/Tech/Shutter/ShutterTest.html
Measurement of Camera Shutter Speeds Using Household* Equipment.
Another one. (*) Note: "household" is defined herein to include a
computer with a sound card and a Radio Shack nearby. By J. Cunningham.
more diy: http://www.xs4all.nl/~wiskerke/html/diy.html
regards, wim
--
http://www.wiskerke.com
Stephe Thayer
> http://www.rit.edu/~andpph/text-shutter.html
>
>
Thanx!!
--
Stephe
Jean-David Beyer
I do not know if I was a typical Deardorff user or not, but I never used
those things. When I take the trouble to take a 4x5, tripod, etc., into
the field, I might as well shoot 4x5 film. If I wanted smaller images, I
would not bother with all that, but take a MF camera instead. Also all
my 4x5 lenses would be the "wrong" focal length for the 2x2.5" images.
If I were typical, then no one ever used the things, so they could save
the trouble and expense of including them.
Ron Wisner designs 4x5 and other size cameras. As far as I know, he does
not include these gizmos in any of his cameras. Perhaps he will tell us
why not.
--
.~. Jean-David Beyer Registered Linux User 85642.
/V\ Registered Machine 73926.
/( )\ Shrewsbury, New Jersey http://counter.li.org
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Kayaker
darkslides, as you suggest, and cut them. You can cut them with a good mat
knife and file the edges so they are smooth. I use a router and a jig I
made for doing a larger quantity of them. I assume you are not worried
about having the edges match up exactly or that they are perfectly clean.
With care and measuring you can come pretty close, though. Bender
Photographic sells modified darkslides for shooting two 2x5 shots on one 4x5
piece of film ($14.95... see www.benderphoto.com/2x5pa.htm ) But, you can
also buy blank darkslides and cut them in the way you suggest to get 4
shots. In my estimation this would be easier and preferable to other
methods of masking, but that's just my opinion. Good luck!
Jay Bender
Bender Photographic, Inc. http://www.benderphoto.com
Mike Jordan <mjo...@europa.com> wrote in message
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Keith Olivier
to your nearest laser cutting centre (will be at least one in every major
city) and they can then cut the required perforations without any fiddling,
mess or distortion. Alternatively they could cut a complete new darkslide
for you. Because the cutting process is very fast, the programming
generally takes longer than the job itself.
All that would be required afterwards would be smoothing the sharp edges so
as not to destroy your light trap on the sheetfilm holder.
Regards
Keith Olivier
St Martin, Germany
"Kayaker" <j...@bossig.com> schrieb im Newsbeitrag
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michael nielsen
If its only for exposure testing and not for keepers why not just insert an
uncut darkslide fully. Pull out an inch - expose, pull out an inch more -
expose again etc. Just like making a test strip in the darkroom.
Michael Nielsen
(relax guys this mail is about photography!)
"Keith Olivier" <keith.oliv...@t-online.de> wrote in message
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Kayaker
That kind of precision is definitely not necessary.... but, whatever.
Jay
Keith Olivier
of work is far cheaper than one might imagine, considerably cheaper than
machining for example.
Unless one is going to do everything yourself, you will end up paying for
someone elses time, which could easily cost upwards of $75 per hour. At
these sort of rates, laser cutting (or even water jet) is really cheap
considering how soon one has a perfectly finished product available.
If it is to be a fully DIY job, then I guess that the most appropriate
process may be to mark out the holes required, drill holes close to the
corners and then cut the openings with a jig saw equiped with an abrasive
blade (as opposed to blades with teeth) However, one will find that
particularly with sheetmetal, a laser (or water jet) allows things to be
done on a one-off basis which could not be done any other way.
In the end, it is up to the individual to decide. We can only offer choices
based on our experience.
Regards
Keith Olivier
"Kayaker" <j...@bossig.com> schrieb im Newsbeitrag
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Kayaker
the plastic ones you get nowadays. I think if you order replacement
darkslides, 4x5 or 8x10, they will be the new plastic ones. These can
easily be cut with a utility knife.
Jay