90mm Schneider 4x5 lens problem?

[ColonelKurtz]

Welcoming opinions on possibilities for the cause of this light leak on my 4x5 sheet film... It looks like it could be a lens issue, but I realize its very difficult to tell, and that the process of elimination, gear wise, will help narrow this down. Any input is welcomed and appreciated. Thanks

[Mark Woods]

Put the film back in the holder in the orientation it was when you shot the image. Set the bellows distance the same as it was when you shot it. This will indicate where the light exposed the film. You can then search in that particular area for the problem. If the problem isn't immediately noticeable, then use a directional light (or flash light) aimed at where the light leak is. You should be able to see the light on the film in the holder. If not, it may be that there was something compromising the light tight ability of the camera/film holder that was a one off. This would be particularly true if this is the only image ruined in this manner.

I hope this helps.

All the best,

[ColonelKurtz]

Thanks, Mark... I've checked everything as you recommended, and my only guess is the film was compromised at some point when it was not in the camera. Using a camera with a brand new bellows, and I checked with a flashlight, etc... Checked the film holders, as well. Can't find anything.

[Mark Woods]

Have you processed another sheet of film directly out of the box to see if it's the film and not the camera?

[ColonelKurtz]

I only made that one picture... A weather system passing through Angeles Crest (not far from you) 3 days ago gave me about a 10 minute window between downpours to make just that one picture. I'm going back up there on Saturday to try and try again.

[Mark Woods]

You really might want to process one sheet of film directly from the box to see if it's a film problem and not a camera problem.

[ColonelKurtz]

Will make sure I do that. Thanks for the tip.

[Mark Woods]

:-)

[ottluuk]

Condensation/fog on part of the front element, perhaps lit up from the rear by an unfortunate internal reflection?

I wouldn't rule out something like that if you can't trace it to a film or light leak issue.

[Doremus Scudder]

If this were a lens issue, I would think that any light leak this bad would be visible on the ground glass when composing the image. Since it is in the top right corner (o the side that the darkslide likely was) I would bet that the back was inadvertently pulled away from the camera body when pulling/inserting the darkslide. The remedy is to pinch the back to the camera body with one hand while pulling/inserting the darkslide.

If that's not the problem, then perhaps a loading/processing accident led to exposure. I can't see if the rebate is exposed by the leak or not, but if so, it likely happened out-of-camera and vice versa.

Do do the check Mark suggests with a flashlight or the like to check for leaks though.

Best,

Doremus

[Paul Ron]

extend the bellows all the way, put a bright light inside. in a dark room, look over the entire camera for light leaking out from the mounted lens, the filmback, and bellows.

[Jerry Bodine]

Colonel, you may get a response from someone suggesting use of a torch rather than a flashlight to look for light leaks ... don't do it, as the flames would probably do more damage than good. :D :D :D

[Robert Opheim]

I have had light leaks from sunlight directly coming through the dark-slide opening when the sun was in alignment with the film holder opening. Years ago a photographer that actively shot 8x10, and 11x14 in Seattle told me that you need to cover the rear of the film holder when you pull out the dark-slide. He used his dark cloth. Recently I have had a reminder of this with a 3/4 inch light leak on two exact shots.

[Bob Salomon]

I have had light leaks from sunlight directly coming through the dark-slide opening when the sun was in alignment with the film holder opening. Years ago a photographer that actively shot 8x10, and 11x14 in Seattle told me that you need to cover the rear of the film holder when you pull out the dark-slide. He used his dark cloth. Recently I have had a reminder of this with a 3/4 inch light leak on two exact shots.
You should also pull the dark slide out only as far as needed to uncover the film and not out of the slot to minimize the chance of fogging.
But did the op look at his diaphragm and make sure that all the leaves are in proper position?

[ColonelKurtz]

Thanks, Doremus. I did all checks, and the only thing I can think of is improper darkslide removal or re-insertion, which I very likely could have done. Will have to make sure I pinch the back to the camera body from here on out.

[ColonelKurtz]

@Jerry Bodine LOL. Its a brand new Chamonix view camera that I did check for light leaks on, and there are none...

[ColonelKurtz]

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Got a pretty much identical light leak on black and white film, so I'm thinking its the film holder. Since I didn't keep notes, I'm going to have to make the mistake at least one more time, before I find the suspect film holder, but the process of elimination will narrow this down.

[Mark Woods]

Well, the problem is now known.

[ColonelKurtz]

Yep, the big auction site is a gamble, as ever. Although I do pull my dark slides all the way out, when making a photo. I'm going to not pull the dark slide completely out on these next 10 exposures (I've only got 5 film holders), and see if that makes a difference.

[Mark Woods]

Have you thought about putting the film holders in the camera without the dark slides and putting a flashlight over the opening to see if you can see any light? Might be a short cut to finding the culprit.

[ColonelKurtz]

Thought about that earlier. The problem is that I loaded all of my film holders again, a couple days ago, so now if the leak has already happened on the new film and I unload the film back into its box, and check the holders and don't see anything with a flashlight, I'll more than likely (without the kind of luck that wins lotteries, and knowing mine, it won't be) end up with 2 sheets of light leaked film, when I re-load it. I think I'll go and shoot all the loaded film, keep track of which scenes were in which holder, and just sacrifice a shot. I shot these unimportant photos to test my new equipment (new camera, lenses, film holders), so when I really get to work, I won't miss any shots... problem is I got out there and forgot to write down which holders contained which scenes. Won't be happening again.

[ColonelKurtz]

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Here are the photos, as they were shot in camera. I'm trying to figure out how the beginning of the burn (the sharp edge of the leak) could have started where it did, as there are no cracks on my dark slides.

[Jerry Bodine]

If both shots were done at the same time, one with color film & the other with b/w film (therefore two different holders), and the anomaly is nearly identical in both, it suggests the problem is not with the holders. If the anomaly was not visible on the groundglass, then the problem lies elsewhere. IIRC many years ago when I shot color film and experienced minor light leaks, the color of the leak was yellow on the tranny - not white - but I suppose a massive leak might be white.

[ColonelKurtz]

If both shots were done at the same time, one with color film & the other with b/w film (therefore two different holders), and the anomaly is nearly identical in both, it suggests the problem is not with the holders. If the anomaly was not visible on the groundglass, then the problem lies elsewhere. IIRC many years ago when I shot color film and experienced minor light leaks, the color of the leak was yellow on the tranny - not white - but I suppose a massive leak might be white.

Hey Jerry,
Yeah now that you mention it, nearly identical light leaks seem like they might be coming from something else other than the film holders, but out of about 10 sheets of film exposed, only 2 have showed leaks, and this is a brand new camera. Both shots were done at different times, between a reload or two, and the numbers of the numbered film holders were not written down to correspond with each scene, so as of now I don't know which film was in which holder. I won't be able to tell if its a film holder until I shoot through all 5 again, keeping notes. Since all 5 film holders are loaded with unshot film, as of now, one option is to unload the film holders in order, check them in camera in the dark with a flashlight, then reload each sheet of film into the exact holder it was in (if I don't find any light leaks with a flashlight). This will hopefully prevent exposing 2 sheets with light leaks instead of one.

[ColonelKurtz]

Update: Just checked every film holder in darkness, with a flashlight. I don't see any leaks, anywhere. I put both lenses on the camera body (closed) and checked to see if light was somehow getting through the aperture blades onto the film plane. Didn't see anything amiss there, either. I'm stumped. Will have to make the mistake again, but not the mistake of not keeping a detailed log. Will update this as soon as I know what the problem is. Thanks Again, everyone.

[Doremus Scudder]

I'm still betting on your pulling the back away from the camera body when pulling the darkslide. Making that same mistake twice is pretty easy and would look the same.

I'd number my holders if I were you, though, and keep track of which one was used when.

I know some don't pull their darkslides out all the way when making a shot, but I always do (covering the opening of the light trap asap with cap or darkcloth or whatever). Having 90% of a darkslide flapping in the wind when I'm trying to make a shot is not my idea of fun.

Best,

Doremus

[ColonelKurtz]

Doremus, I'm really hoping you're right, that it was "user error" and not a leaking film holder. I went back and re-scanned the 2 negatives (attached here, in position as if you were looking at the scene on the back of the ground glass) and saw that the light leak is not on either of the film's rebates, so this helps to support your theory. Until I find out, every shot gives me anxiety :( Great work at your site, by the way...

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[ColonelKurtz]

Update on this: I haven't had any more light leaks on film from any of my film holders, since I started pinching them to the back of the camera body whenever inserting or removing the dark slide. Thanks again, everyone...