Light leak?

[Ash]

I'm getting a strange light leak on 4x5 film.

I received a few 4x5 holders with the Cambo and they were pre-loaded with film, so their origin is unknown, but I trust Jim can load film properly!

One holder has provided the same light leak on both sides now.

The leak:
doesn't stretch outside of the frame - unexposed area doesn't show any leak there
is broad and quite faint, a line but very fuzzy across the frame
about 1/3 along the film, on the side towards the loading mech (where the film slides in) - along the short side, not down the centre (top to bottom if film is landscape)


Appears to be clean light, not a ghost image, especially by it's shape.

I would have thought it was a camera fault, but the last time I got this leak, I was using a different camera, so unless I have the exact problem with 2 cameras, I'm lost!!


I guess it's the film holder DDS but not stretching to the unexposed edges is a mystery in that case!


Any ideas?

[Patrik Roseen]

I have a hard time trying to understand what your light leak looks like and where it is located.
Do you know the history of the filmsheets, where have they been before entering your filmholders?

Are the holders plastic or wood? (Woodholders could be bent)
I would check the loading flips for light leaks (check the gafferstape).

Look at the darkslide to see if it is non-flat. Maybe you have put the 'faulty' darkslide on both sides of the holder. If it is non-flat the light trap will not work as it is taken out and inserted.

The holder could be worn so that it no longer is flat against the camera back.

Go through your own handling. Maybe you have pulled out the filmholder slightly while pulling the darkslide.

You probably need to provide more info...picture?

Good Luck!

[Ash]

Hi Patrik, looking at the scanned neg, the initial leak I could see on the film doesnt appear noticeable at all, rather two long leaks along the length of the neg, which makes things worse I think!!

I'm not sure what is going on, but here is the awful neg scan. 400kb file, linked not embedded.

http://i2.photobucket.com/albums/y43...titled-3-3.jpg

I'll reshoot the photo now on Kodalith Ortho using the same holder and see what happens

[Louie Powell]

Is that a light leak, or is it uneven processing?

[Ash]

that neg is probably uneven developing... but the leak I saw previously looks too uniform for a paterson orbital to have been the problem

I'm developing the second neg now, and it looks like all is good with the holder after all... well I think so anyway.

[Colin Robertson]

Ash- the problem is your orbital processor. The streak you describe is caused by local overdevelopment under the 'blade' part of the lid. As you rotate the processor, the chemistry 'swishes' under the blade, and the extra agitation causes overdeveloping. Trust me- I went through this, trying to track down a non-existant light leak.
To prove this, either 1) tray develop a couple of sheets. If you still get streaks then okay, you have a light leak. If not . . it's the processor OR 2) process an unexposed sheet. It should come out absolutely clear. Any streaks or mottling MUST be processing related.

[Ash]

Colin, you must be right. The latest negs look good. One is underexposed quite bad, but I bracketed on both extremes, and the underexposed doesn't show signs of a light leak either.

If the problem lies with the paterson orbital, what method of development for 4x5 would you recommend. Bear in mind I got the orbital brand new for £10, so paying huge sums for another development system is gonna make me choke!

[kmack]

If you can't tray develop you may want to try the 'taco method' with a Paterson tank. Or you could make your own tubes. A quick search here or on APUG will get you all the info you need for either.

[Ash]

I'll look into those methods. Dust is my main enemy.

Here's a straight neg scan from the Ortho. No levelling in photoshop. It needs rotating though. (cropped scan since I have to splice 'strips' from the 35mm scanner lol)

http://i2.photobucket.com/albums/y43...5orthocopy.jpg

[Vick Vickery]

When are you gonna be the proud grandparent of the little leicas???? :-)