Lightleak or vignetting or sunshine

Mats_A · Mar 12, 2010

As I said in an earlier thread I tested an ICA 9x12 camera today. I had no film so I cut some Ilford MV Glossy paper to fit and took this image at 1 sec f 12,5. I used my DSLR as a lightmeter and it said 1/40 sec f13 on ISO 200.

I am surprised that there is any picture at all. My question is about the top of the tree that is much darker than the rest. I do not have much experience with large format or paper negatives so please bear with me.

Is it a light leak? Don't think so since the sky is not darker.

Is it vignetting? I did raise the front quite a bit to get the tree in the picture. If it is vignetting should not the sky also be darker?

Is it just the sun shining on the top of the tree? If so then the contrast of a paper negative is really something.

This is interesting. I need to get me some Foma 9x12 sheets.

r

John Koehrer · Mar 12, 2010

Not to be an old cranky pants, but if you're testing the camera start with a straight shot, don't introduce other variables.

Mats_A · Mar 12, 2010

John Koehrer said:
Not to be an old cranky pants, but if you're testing the camera start with a straight shot, don't introduce other variables.

There were no variables here. I did not have any film so I used paper.

r

Ian Grant · Mar 12, 2010

Into the light old uncoated lens, perhaps you ask too much.

It's an OK image but don't read to much from it, I have & do shoot with lenses of that vintage some a lot older, some slightly newer but they behave differently and you have to l,earn just how an individual lens performs.

Ian

leighmarrin · Mar 12, 2010

Might be a light leak from the felt light trap. I notice the top of the tree is unaffected, and this would be the furthest away from the light trap.

Do you have a small flashlight that holds only one AA or AAA battery? If so, put it inside the camera body, put in a plate holder, and sort of "roll" the camera until you think the lit flashlight is near the felt light trap at the top of the camera, pull out the dark slide and turn out the lights. You'll probably see light leaking through the light trap... This is a common problem with these great old cameras, but the felt strip on the camera body and plate holder can be replaced.

--Leigh in Santa Barbara, Calif.

Mats_A · Mar 12, 2010

leighmarrin said:
Might be a light leak from the felt light trap. I notice the top of the tree is unaffected, and this would be the furthest away from the light trap.

Do you have a small flashlight that holds only one AA or AAA battery? If so, put it inside the camera body, put in a plate holder, and sort of "roll" the camera until you think the lit flashlight is near the felt light trap at the top of the camera, pull out the dark slide and turn out the lights. You'll probably see light leaking through the light trap... This is a common problem with these great old cameras, but the felt strip on the camera body and plate holder can be replaced.

--Leigh in Santa Barbara, Calif.

I did a test with one paper for 45 min inside the camera with the darkslide removed. That paper was white when I developed it.
But was an other holder. I will try your suggestion. Sounds like an easy way to test it.

And I know this is an old uncoated lens that will newer be perfect. I am just fascinated that you can do so many things with cheap, old cameras.
And I will try to change the felt, purchase some proper film and continue to play with it.

This is fun!

r

John Koehrer · Mar 13, 2010

shimoda said:
Is it vignetting? I did raise the front quite a bit to get the tree in the picture. If it is vignetting should not the sky also be darker?

Front rise IS a variable and when you raise the front it could give you an uneven exposure across the negative.
Try it without the rise.

Doremus Scudder · Mar 14, 2010

Shimoda,

This looks like a bad case of flare to me. An uncoated lens (without lens hood) in that bright environment, shooting into the bright sky with (probably) lots of reflective snow, etc. just out of the picture is a good recipe for what you got. This would be compounded by the long exposure time needed for the paper you used instead of film.

It is definitely not vignetting, which would show as an unexposed arc, or portion thereof, at the top of the frame. The corners would be affected first, which is not the case with your shot. It could be caused by light falloff, but that would be more of a factor with a very short focal-length lens, which you don't seem to be using.

Try some other shots with a less-reflective subject, use a lens hood and bite the bullet and buy some film

Best,

Doremus Scudder
www.DoremusScudder.com

largeformat pat · Mar 14, 2010

I would agree, Flare. The darkest parts are washed out.
Pat

david_mizen · Mar 14, 2010

isnt the top of the tree just plain old over exposed (black on paper is excess light?) and the snow in the foreground is plain old under exposed (no detail = no light?) ???

wa1vgb · Mar 14, 2010

I am going to go with too much shift. The snow in the picture is white, so the image is displayed as a positive. Not enough exposure on the top.

Ian Grant · Mar 14, 2010

wa1vgb said:
I am going to go with too much shift. The snow in the picture is white, so the image is displayed as a positive. Not enough exposure on the top.

These camera's don't allow enough shift (actually rise) to cause that kind of problem and the lenses cause total vignetting of the corners, as the OP says the sky tone isn't darker, just the tree.

These lenses can be very prone to flare because they are uncoated when you read books from that era they recommend not to shoot into the light.

Ian

Lightleak or vignetting or sunshine

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