prevention of film holder light leaks

[rolee]

Hello everybody,

I am new to large format, shooting 4x5 for a year now. I shoot mostly alpine landscapes and the results of my negatives are very inconsistent. Until now I thought the problem was uneven development of the negatives but more recently I started to think of light leaks.

So I tested my film holders today - and I recognized light leaks with all of my seven film holders (4x5 Fidelity Elite holders).
In a dark room I put a flashlight into the bellows of my Intrepid 4x5 camera, inserted a filmholder and pulled out the dark slide. I could see light through the felt of the dark slide slot (at a certain angle), and even more when the slide was still a bit inside and bent (see pictures).



It seems not much, however, when the film holder points towards the sun when taking a photograph it obviously is enough to cause film fogging.

I bought the film holders used from two different sellers and they looked very good and not much used. Is it possible that even quite new holders cause light leaks? What do you do to prevent light leaks? Cover the film holder using a dark cloth when taking the picture?

Thanks!
Roland

[Leigh]

Hi Roland, and welcome aboard.

I use a method with my dark cloth that might help.
It certainly could be used to confirm the diagnosis. I use it all the time.

When I set up the camera, I attach the dark cloth to the top of the camera with a pair of clothes pins.
When done using it, I fold it up on top of the camera so I can load a filmholder.
Then I drop it down over the back of the camera, so it totally shields the holder.

Even if you don't do this all the time, it's a simple and cheap way to test your evaluation.

- Leigh

[Vaughn]

I pull and insert darkslides under the darkcloth. A little tougher with 8x10 and 11x14, but it is a habit now.

[Alan Gales]

I bought the film holders used from two different sellers and they looked very good and not much used. Is it possible that even quite new holders cause light leaks?

Have you ever heard of Murphy's law? Yes, it is possible.

You could always buy new film holders but most of us (me included) buy used holders. I buy ones that look as new as possible and haven't had any problems.

I did once buy some well used 8x10 film holders cheap for a friend that ended up having light leaks. It was weird. They leaked part of the time but not all the time.

You could drape your dark cloth over the film holder. I drape mine over my bellows when making an exposure just as an added precaution. I'd still repair or replace the leaky film holders you have. I've never done it but some on here have replaced the tape joints.

Welcome to the forum!

[Willie]

The "Morley Baer wrap". You to all the focus, compose and insert the film holder and wrap the bellows & back with the dark cloth so light is blocked out. Baer used an 8x10 many would have gotten rid of for years. Has light leaks in the bellows so he would wrap it with the darkcloth.

[Maris Rusis]

If I face a situation where the sun will shine straight down the dark-slide slot I attach the ground-glass back to the camera upside down. The film holder goes in from beneath and when the dark-slide is pulled down the slot sees the ground not the sky. Then the focussing cloth is wrapped around as added light proofing. If the rear standard of the camera is a long way forward to work with a wide angle lens and I can't push the film holder in from below then the entire camera can be tilted over (carefully!) 90 degrees. Again the dark-slide slot can be arranged to see the ground and not raw sunlight.

[Doremus Scudder]

A light leak from the light trap of a film holder makes streaks on the film, usually closest to the opening. It is random and non-image exposure and looks nothing like inconsistent exposure or development. It would really help to see a photo/scan of the negative(s) in question. Just take a smart phone photo of it held up to your computer screen or open window.

Yes, you may see light through the light trap from your test, but we can't tell from the description of your problem that you actually have negatives damaged from such a light leak.

Some pointers for preventing such leaks around the light trap:

It helps to keep the time the darkslide is out to a minimum. Pull the slide, make the exposure, replace the slide. For those times when you have to wait a long time for things in the scene to settle down (wind motion, etc.), then do cover the darkslide opening with something.

I try to cover the holder with something even when the darkslide is out for short times. I work a lot without a dark cloth, so use other things a lot. For example, if it's not windy, I'll simply pull the darkslide and then hold it over the light trap (I can balance it on the holder and camera back for vertical shots). I also hang my hat/cap over the darkslide opening to block stray light, especially when I need the darkslide as a lens shade. For those times when I know the darkslide will be out a long time, I have made a small cardboard cover for the top of the holder out of the bottoms of old film boxes. It's a press fit and stays on even in strong wind. Of course, the darkcloth will work well too if you're using one.

I've used Maris' trick of re-orienting the camera back so that the darkslide opening doesn't face the sun as well a time or two.

However, maybe a light-trap leak is not your problem at all; let's see the negative.

Best,

Doremus

[Pfsor]

Rolee,
as you are new to LF photography, don't condemn yourself to years of working with defective film holders. Bellows, cameras, film holders are all conceived to work properly in daylight without need of covering them with dark clothes and hoping it will work!
I have never needed to cover my cameras or film holders with anything while enjoying taking pictures. At most I take care of not pushing the dark slide sideways when pulling it from the film holder.
If your film holder doesn't work as it should repair it or get new ones, properly working. Anything else is just giving up on the pleasure of taking pictures with correctly working equipment.
If you want to have years of satisfactory photography start with good working equipment first - it is well worth it! Just my 2 cents.

[rolee]

Hello and thanks everyone for your comments! Up to now I refused to take a dark cloth with me. This will change now! Also turning the filmback 180° towards the ground is a good idea, thankyou.
When analyzing my negatives I realized that they turn out ok when the camera is not in direct sunlight when taking a picture.

In reply to Doremus' post, here is an unmodified scan from a recent negative. It was shot in portrait orientation, with the dark slide towards the sky. The light streaks are obviously near the dark slide slot.



I also made another test yesterday, loading my holders with paper instead of film and placing them in direct sunlight for 5 minutes (as paper is less sensitive). Then I developed the paper pieces.



1 - negative paper control
2 - positive paper control
3 - holder in the camera, darkslide out, slot towards the sun
4 - holder in the camera, bending and pulling darkslide in and out several times, slot towards the sun
5 - holder in the camera, darkslide out, pulling the holder a little away from the camera for 2 sec
6 - holder alone in direct sunlight, different positions, for 15 minutes
7 - holder alone in direct sunlight, pulled darkslide a little for 2 secs
Darkslide slot is on the bottom of each piece. I did not test every holder for every situation. But according to the light leak test with the flashlight they all are about the same.

So for me it seems clear where the problem comes from in my case -according to pieces 3 and 4. It makes a difference how straight you pull out the slide, and if you are in direct sunlight or not.

Pfsor, as my holders where near to new (at least they looked like it) I am wondering if even new holders are completely free of light leaks - especially when having the camera in direct sunlight.

[Pfsor]

Pfsor, as my holders where near to new (at least they looked like it) I am wondering if even new holders are completely free of light leaks - especially when having the camera in direct sunlight.

Yes, film holders are conceived in such a way that if properly working they can be used in direct sunlight without the need of covering them with dark cloth.
By the way, I never use dark cloth, (too bulky for me) and I rather use a home made hood (made of paper) in the case the sun is shining on the gg.