View Full Version : Light leaks in film holders

Diane Maher
1-Sep-2010, 10:31
Do light leaks in film holders develop suddenly?

I just picked up some 8x10 Portra images from the lab and it seems like one of my Fidelity holders is suffering from a light leak on both sides along the long side of the neg. I'll do some scans and post some pics later. I bought the holder new in 2003 (or thereabouts) and it hasn't been abused.

I had used this same holder back in May during a workshop and haven't seen any evidence of light leakage on those negatives. I hadn't used it since then until last Sunday and POOF! there's a light leak. :confused:


Peter K
1-Sep-2010, 10:39
I just picked up some 8x10 Portra images from the lab and it seems like one of my Fidelity holders is suffering from a light leak on both sides along the long side of the neg.
You're sure there is no other reason as the holder? It sounds more like the lighttrap between holder and camera wasn't working properly because the holder was inserted in the camera the wrong way.


1-Sep-2010, 10:41
... I would like to see your scans. I just got back a bunch of 4x5 negs with issues that look like light leaks, but I'm not sure.

On my Chamonix, the back is relatively loose, so I have to be a little careful when pulling the dark slide - it could cause a leak, but I assume it would look like a haze on the neg...

1-Sep-2010, 10:46
The light trapping on the long sides of the holder is accomplished by the dark slide engaging a rabbet molded into the holder body; it would seem that short of extensively warping the holder (a closed up car in the sun in August, maybe?) there is not much that could suddenly change the light trapping.

On the other hand, if you accidentally exchanged dark slides with a holder of different make or vintage, the dark slide widths could be different enough to cause this.

Another possibility is that the back didn't seat properly, allowing a bit of light to shine across the narrow dimension. It seems unlikely, but perhaps the shape and density of the leak pattern will give you a clue.

Doug Howk
1-Sep-2010, 10:57
Diane, if it had only been one side/neg that had issue, then I too would suspect an improper seating of the film holder. With both, not so sure. Still, its good practice to "jiggle" the holder after seating just to be sure that it is in place. May also want to test with some inexpensive B&W film and that holder. Alot of people prefer would rather than plastic because of seating issues.

1-Sep-2010, 12:35
Did you drop the holders at any time..

Jerry Bodine
1-Sep-2010, 16:58

Not sure how your camera is constructed, but if you haven't already done so, check the light trap on the camera back itself. A few years back my 4x5 trannies came back from the lab with a number of them ruined by light leaks in the same corner of the frame. That made it easy to locate. Turned out my Sinar Norma back has a narrow strip of trap material (like velvet) cemented into a groove in the camera back, and this strip had become "unglued." I ordered a small roll of this material from Sinar as a replacement and re-glued it in place ... problem solved. It seems that repeated sliding of the holders in and out caused it to let loose. Unfortunately these were all shots from a strenuous one-week backpack trip - very disappointing!


Robert Vigurs
1-Sep-2010, 20:33
I use old wooden holders with the 2D. Ebay specials no less. The first time I used them I had some light leaks at the top where the slide goes in. Since then, I put them in a satchel after loading in the darkroom, and they stay there until used. I shade them with the dark cloth, wind permitting, then place them right back in to the heavy material satchel. They stay there until darkroom processing, and I have not had a leak since. Again, these are ebay specials. 3 for $22,

Jim Noel
2-Sep-2010, 15:00
Having and using an adequate size dark cloth will remedy problems caused by warped holders,and many other faults which cause light leaks.

The cloth should be large enough to wrap around the camera with ease. A good quality black T-shirt size XXL is excellent, and far better than the tiny dark cloths I see many people using. Just stretch the neck around the back of the camera.

The cloth is not just for focusing. Keep it wrapped around the camera at all times. If it is large enough, it can even help with light leaks.

My small dark cloth for use with 4x5 and 5x7 is 4x5 feet. The one I use for 8x10 and 7x17 is 5x8 feet. I do frequently use a black T-shirt with the 4x5 when I want to really travel light.

Jim Noel
2-Sep-2010, 15:01
It should have read, " can even help with bellows leaks."

2-Sep-2010, 15:58
The rule of thumb regarding dark slides is simple , if they are light tight they do not need to be wrapped in any thing , if they let in light they are not dark slides . they do develop leaks at times and the best way of checking is numbering the slides and developing in order . The most common leak is on the bottom edge which can be caused by bending back the end flap a tad too much . the effect of this is a line of light going up the long edge of the film generally wider at the point of the leak and reducing in size up the edge

Diane Maher
3-Sep-2010, 07:25
Sorry, it took me a while to get the scan up. Here is the scan. Both sides of the holder have similar issues. I am wondering if picking up the holder on the sides would cause this. Hmmm. Post number 666. :)

3-Sep-2010, 07:33
no x-ray involved? not that I know what x-ray damage looks like, but the leaks (or whatever they are) that I have on my recent negs are a splash in the corner with much more dramatic highlight and a fast fade out... will upload images soon

Jack Dahlgren
3-Sep-2010, 07:56
That looks like the film holder is not seating correctly. Remember it could come off the seal slightly when you are removing or inserting the darkslide even if it is seated when you are taking the shot.

Peter K
3-Sep-2010, 08:15
no x-ray involved? not that I know what x-ray damage looks like,
Depends on the accelerating voltage a different color cast in the form of a shadow made by the subjects between the x-ray-source and the film.

al olson
4-Sep-2010, 05:57
From my experience chasing light leaks, I would rule out a brief separation of the holder from the camera back or an improperly seated holder. For these leaks the edge of the holder usually throws a shadow (typically around 3/8") where the exposed area is normal. The fogged area then thins out as it gets farther from the side where the holder was separated.

If it were separated for a longer time the whole transparency would be blotchy or blown out. In your case you have stripes.

Ordinarily, since your rebate is unaffected, it would appear that if the film were exposed, it happened while the film was in the holder.

Unless, it is a processing problem. Since the rebate is not exposed I would assume that even bad processing would leave it black. Note that neither the colors in the light stripes nor the dark stripes appear normal. Furthermore the stripes go across the negative in about the same density, which to me rules out a light strike from a brief holder separation. I would attribute the bad colors to exhausted chemicals or insufficient agitation.

Is this a dip 'n' dunk lab, or do they use an ATL or other processor?

I should add that I had a situation with black and white development where the lid on the Jobo tube was not tight and the chemicals leaked out. The rotary motion left streaks much as in your transparency.

4-Sep-2010, 06:23
no x-ray involved? not that I know what x-ray damage looks like, but the leaks (or whatever they are) that I have on my recent negs are a splash in the corner with much more dramatic highlight and a fast fade out... will upload images soon

I've not had obvious x-ray damage on any of my own films that I can detect. Even those that I know went through airport scanners a number of times.

But from images I've seen posted elsewhere the damage from x-ray seemed to undulate across the film.

But the bottom line is everyone's film is subject to x-ray damage these days from shipping and mailing. One never knows what packages will be heavily x-rayed and where during their travel. Bob G.

John Kasaian
4-Sep-2010, 09:17
Test the holder with some B&W photo paper. That should tell you a lot.

Diane Maher
4-Sep-2010, 12:17
I did not travel any distance with this holder and it hasn't been through an x-ray. John, I don't have any b/w photo paper or a way to satisfactorily develop it (no darkroom).

I think that the lab does dip n dunk, but I am not certain. :(

5-Sep-2010, 02:07
... Hope you don't consider this a thread hijack, Diane, but here's a bit of my light leaks

I think it's the holder, but on the other hand they are (mostly - I have more than these) in the corner where the dark slide goes in, and not the corner where the flap is...

But, all comments and suggestions are warmly received :)

PS: sorry for the cropping - the leaks are actually a bit more evident than what you see here. They are developed at HSL, so that should rule out the development issue. Another last thing to inform you about is, that I use a Chamonix 4x5 and it's back is very loose in order to accommodate all kinds of backs... so it could maybe happen if I accidently 'flap' the back a little out when pulling or inserting the dark slide...?


Bill Burk
6-Sep-2010, 16:18
I just solved a light-leak. I thought it would be clever holding my head under a black t-shirt and walking out in bright daylight inspecting everywhere for leaks but no luck I only saw absolute pitch black. I thought I'd try a laser. Nope nothing showing.
Then my wife handed me a brand new little night-vision green Photon Micro-Light. I put the developed negative in the suspect Grafmatic and shone the light all around until I saw the shadow that matched the fog. That gave me a bearing on the leak. I started running that micro-light around the camera at places that could have caused that shadow and sure enough - there it was - a green sliver.
Afterward I tried to find that same sliver by daylight and still couldn't see it. I don't know how bright those little LED's are - but apparently it is brighter than the sun. I recommend them for the purpose of finding light leaks. The Micro-Light is great because the tip of the LED sticks out and you can press it right up to things. I don't think the color matters that much but night-vision green sure worked.
I also had a leak in unexpected place: the shutter blades of a Bessa II didn't fully come together all the time. That was and remains a devil because it's intermittent.

8-Sep-2010, 14:33

The nearly uniform density loss across the width of the film, in bands with "normal" exposure in between, suggests fogging in the darkroom, or possibly before the film was used. It may not be enough to show up in the rebates, although the edge printing would probably look a little different in the fogged zones.

It would be interesting to make a scan, and then use Photoshop or the equivalent to adjust the density and color balance of the damaged zones. If set of adjustments is uniformly effective over the whole sheet, then it is highly unlikely that the problem is camera-related. It is hard enough to get perfectly uniform exposure when using a lens and shutter designed for the purpose; it just doesn't seem reasonable that a random light leak would do as well or better :)

If, after correcting out as much of the damage as possible, there is a pronounced gradient in the remainder, this may help you triangulate the location of potential leaks. But if the edge printing is altered by the fogging, then the camera and holder are pretty clearly ruled out.