identify the light leak!!

[jamie c]

Attachment 33338

can you identify, or suggest where this light leak might be coming from?
do you think it is more likely the holder, or carrying box?

thanks for any advice.

also - don't judge the image! it is just a behind the scene documentation.

[Vaughn]

If this is an inconsistant problem (happens rarely, not always the same holder, etc), I would consider operator error as a probable cause. Specifically, pulling slightly back on the darkslide as one pulls it up and out of the holder before taking a photo, or as one inserts it after the exposure. Pulling back, especially if the camera back's springs are not robust, can allow some light to sneak in between the holder and the camera.

But I would do the old flashlight in the bellow test -- especially checking the back of the camera.

Vaughn

[Don7x17]

Look at the pattern of the light hitting the film --and note that there is an unaffected area next to the edge of the holder. That that it does not occur on the bottom (we cannot tell much about the top due to the lighter skies).

It looks like the light is coming from both the right and the left (leaving the shadow next to the dropoff next to the film edge).

It could be any of the following (in no particular order)
1) Holder is slightly smaller dimensionally than the seat behind the gound glass(where you put the holder)
2) Holder is warped.
3) bellows on both sides have pinholes
4) light trap leak (recall image is upside down). I'm surprised we don't see something in the way of streaks extending up from the bottom which I'd see before in a bad holder

Try illuminating the extended bellows in dark room to view pinholes (cover back with holder). Check around the holder behind the groundglass to see if there is light leak on the sides or warpage.

if that didn't find it....

In the field, try images under similar conditions of the image posted. Make one with the darkslide pulled as you did previously. On a second image, cover the groundglass/holder with darkcloth and pull the slide. Keep the holder covered.

[jamie c]

thanks for the help.

j.

[arca andy]

It looks like the camera was in direct sunlight when the photo was taken so maybe thats where in the inconsistance comes in.
I would guess either its the holder or maybe there is not enough force from the camera back to hold the darkslide into the camera correctly.
You could also check the little velvet/foam light seals of the camera if it has them.
But hey that means more mucking around with your LF which is not bad thing
Andy

[dsphotog]

The film edges indicate fogging had to occur while the film was in the holder, not during processing.

[Doremus Scudder]

My first vote would be for accidentally pulling the holder away from its seat at the top of the camera back when removing or inserting the darkslide. I always pinch the spring back to the camera back with one hand while pulling and inserting the darkslide (after having learned the hard way...)

However, do check the holder for light-trap leaks, etc. If this is a one-off, it's probably operator error as above.

Best,

Doremus Scudder