Light Leaks? First time ever...

[johnmsanderson]

Hi Gang

Any thoughts on these? Shot on an 8x10 Arca. Never had these before and same camera for years. Bellows holes, perhaps?? No problems when I switch out to 4x5.

wtf.

171455171454171453

[xkaes]

Nice shots. BUMMER. Could be a bellows leak or film holder. Looks like a BIG leak. Test for bellows leak FIRST by putting a BARE light bulb in the rear at max extension in a darkroom. Cover the back with a dark cloth. Easy test. THEN move on to the film holders if you need. Pinholes are easy to fix -- if you can find them.

[chassis]

I’m going to say darkslide light seal leak. All images have leaking on the darkslide end of the image along the short dimension. Some of the leaks seems pretty massive or acute. What does a visual inspection of the film holders tell you?

[LabRat]

+ 1 on holder lighttraps... Insert slides straight in, and use focusing cloth over them while pulling/inserting slides, and check light traps in the dark by pulling slides on empty holders, placing the front of the trap area against a table edge (to block light), and shining a very bright flashlight from the inside of the film area, look through the open outside slot and look for tell-tale traces of light coming through, particularly near the edges...

Good luck finding your (Halloween) gremlin!!!

Steve K

[xkaes]

Were they all taken with the same holder? Then it's the holder. If not, then consider a bellows leak first. I hope you mark your holder and take notes, like many of us do, to track down these types of problems.

[chassis]

Another possibility is that the film holder is systemically not being inserted fully. I had this problem for a while in my early days with large format. Be sure to know when the film holder is fully seated in the camera back. If it is not , light leaks are possible at one end or the other, mainly along the short dimension.

[Jerry Bodine]

Do you habitually pinch the gg frame and rear standard frame together when pulling AND inserting the darkslide (without bending it) to keep the holder in contact with both frames? It may be that the springs that serve this purpose are weaker on the 810 than on the 45. Another good habit is covering the bellows with the darkcloth so pinholes cannot bite you.

[Doremus Scudder]

Do you habitually pinch the gg frame and rear standard frame together when pulling AND inserting the darkslide (without bending it) to keep the holder in contact with both frames? It may be that the springs that serve this purpose are weaker on the 810 than on the 45. Another good habit is covering the bellows with the darkcloth so pinholes cannot bite you.

+1 for this or for a filmholder seating problem unless the problem is all from the same holder. Chances of three holders having defective light traps like this is slim.

Doremus

[johnmsanderson]

Well I had three more holders that I had processed and marked which was which, out of 6 of those sheets only 1 had a leak:

171558

It's possible this holder was used for some of the others as well because they are all color negative. This one pretty much correlates with sun position -- even tho I did have the focusing cloth over the back of the camera.

I do have many pinholes in the bellows, but nothing seeming too great.

:mad:

[xkaes]

Given the position, it looks like a big leak (crack/split?) in the film holder -- which would not be covered by a dark cloth on TOP of the camera -- or a leak where the lower right corner of the bellows is attached to the camera body. Both are pretty easy to test -- and small pinholes are easy to fix (I'll try to remember to check my own -- one of these days!)

[Jerry Bodine]

A seriously leaking holder (crack/split) can cause a problem even before it's inserted in the camera, obviously.

[johnmsanderson]

I've inspected the holder and I don't see any cracks.

[David Lobato]

I also believe they are the film holders. Even the film rebates with ID markings were affected. I have taken a small LED light and the holder into a darkroom. Shine the light inside the film area and look on the exterior surfaces of the holder, and then the opposite with the light from outside and examining light leaks inside where the film is. Also check the dark slides. I've had very thin dark slide cracks that were very hard to notice, and use a flashlight behind the dark slide in a darkroom while you warp and bend it slightly.

If you don't find anything, do the same approach but with the 8x10 back and a film holder in a darkroom. Shine the flashlight into every corner and edge and look for stray light coming or going where it shouldn't be. Look for a small foreign object that may cause a tiny gap between the film holder and camera back.

When you find a bad dark slide, or film holder - mark it conspicuously, and throw it away or dispose it so that it never gets back into your work flow.

These methods have worked for me in crazed exasperation with light leaks.

[johnmsanderson]

Turns out it was my Harrison Film Changing Tent.

Some of the black rubbery lightproof coating which is on the 2nd layer of the armholes section began flaking off and leaking light through.

Oh well!

[Doremus Scudder]

Glad you found your problem. Also, this is a good reminder for us to check every stage of the process when trying to diagnose a light-leak. I was stuck at the post-loading part...

Best,

Doremus

[xkaes]

Some of the black rubbery lightproof coating which is on the 2nd layer of the armholes section began flaking off and leaking light through.

I remember when, many years ago, I discovered the same thing happening to my first changing bag while out in the wilderness. It was a complete surprise to me, when I removed my hands and found them covered in large, black, rubbery flakes! But I was lucky because it was early in the morning and not very bright outside. For the rest of the hike, I changed my film at night, so I suffered no loss. I, of course, bought a new bag, but learned that they wear out from age and use, etc. Maybe some last longer than others, but I think I'll check mine -- TODAY!!!!

Thanks for the unintended tip/warning.

[johnmsanderson]

Glad you found your problem. Also, this is a good reminder for us to check every stage of the process when trying to diagnose a light-leak. I was stuck at the post-loading part...

Best,

Doremus


So much can go wrong with LF, but then again so much can go great.

[GMason]

Hi. My dear wife loaded and exposed some velvia to capture the fall colors on my father's mountain house.

However, something bad happened. On all the picture she took after loading and exposing the film.

Could you diagnose the cause of it? (I suspect unproper loading)

[Jerry Bodine]

I suspect you're right about improper loading, but there appears to be another issue as well. The first image shows on the left edge what looks like a film rail at the film's entry point - which indicates, since the image is right side up, that the holder was inserted into the film back from the bottom. This could indicate that the darkslide locks, if present, are loose and allowing the darkslide to open somewhat during handling prior to exposure; but I think it is more likely caused by loading the film under one rail but not the other rail. This would prevent proper closure of the darkslide into the flap. Both images seem to be affected by this same mishap. Also, in the second image at the top left, there is what looks like a partial shape of a pentagonal aperture opening resulting in overall lens flare (consistent with the direction of the tree's shadows). So the lens was not shaded during exposure. Both images suffer from the lens flare.

[ericantonio]

Turns out it was my Harrison Film Changing Tent.

Some of the black rubbery lightproof coating which is on the 2nd layer of the armholes section began flaking off and leaking light through.

Oh well!

Wow, that's good sleuthing!

[GMason]

I suspect you're right about improper loading, but there appears to be another issue as well. The first image shows on the left edge what looks like a film rail at the film's entry point - which indicates, since the image is right side up, that the holder was inserted into the film back from the bottom. This could indicate that the darkslide locks, if present, are loose and allowing the darkslide to open somewhat during handling prior to exposure; but I think it is more likely caused by loading the film under one rail but not the other rail. This would prevent proper closure of the darkslide into the flap. Both images seem to be affected by this same mishap. Also, in the second image at the top left, there is what looks like a partial shape of a pentagonal aperture opening resulting in overall lens flare (consistent with the direction of the tree's shadows). So the lens was not shaded during exposure. Both images suffer from the lens flare.

Thanks a lot. That's very helpful.

[xkaes]

I checked my "new" changing bag, today. Like the other ones I'm seen/used it has an inner and outer cavity -- it's a bag in a bag. The outer bag has a layer of black latex/rubber on the inside, but the inner bag lacks a latex/rubber layer. It is in that outer cavity where the latex/rubber deterioration occurs. You can only examine this layer by looking through the loading end -- not the arm ends. I have no idea if other bags are constructed differently.

But I checked my "newer" bag today, and everything looks great. Now it's time to check the oils in my car!

[Jerry Bodine]

Thanks a lot. That's very helpful.

PS: One more caution - FWIW, it looks like your format may be 5x7". This is not exactly the same size as 13x18cm film (the European version). 5x7 film is a bit narrower (maybe 1/8" less) than 13x18cm, so that the 5x7 film may not engage both rails of a 13x18 holder; and 13x18cm film will buckle if inserted into a 5x7 holder. But both holders have the same external dimensions and will fit in the same back.

[keptamon]

Hah! I am new at photography and I a have similar type light leak issue. Just read the whole thread to figure out the problem. Jerry Bodine@ advice looking solid. I will try to do it (https://theeffectiveguide.com/best-tactical-flashlight/) myself.