Diagnosing a Light Leak

[sperdynamite]

I'm trying to diagnose light leaks. Do these look like they are camera back related or film carrier related? These leaks are almost always in this basic spot.

Thanks!


197264

[Vaughn]

Looks to be a light leak when the holder is in the camera and the darkslide removed. Possibly due to not drawing the darkslide straight up. If the darkslide is pulled slightly towards the back, some light might sneak in if the holder is slightly pulled away from the camera back.

If you put a holder in the camera, remove the lensboard, and in a dark room, stick a flashlight in the camera, see if any light shines from the top of the camera back. Pull the darkslide and try it again to see if it is the film holder. It helps if the holders are numbered and one can tell if it is the same holder having problems.

[Doremus Scudder]

I'm with Vaughn on this. Learn to pinch the back to the camera body with your free hand while pulling/inserting the darkslide.

However, a check like Vaughn describes for light leaks is a good idea. Some cameras have felt or foam as a light seal for the back. Some of this may be missing or degraded. If your camera is wood, check for warps too.

Best,

Doremus

[Bob Salomon]

I'm trying to diagnose light leaks. Do these look like they are camera back related or film carrier related? These leaks are almost always in this basic spot.

Thanks!

Don’t pull the slide out all the way and see if you still have the leak. Mark your dark slide at the point where the film area is fully uncovered to know how far to pull the slide out.
197264

[sperdynamite]

Is it at all possible that this leak came from a semi loose lens board?

[Mark Sampson]

I don't think so. If it were coming from that far away it would look more diffused. Note the relatively sharp edges almost parallel to the film edge. The light leak is probably very close to that spot. Of course a loose lens board should be tightened up anyway.

[sperdynamite]

I tried the trick with the flashlight and I can't see any leak no matter how I pull my darkslide out. I'm going to order some RC paper and do some tests next week. It's pretty baffling frankly. THe loose board is an issue I know I have with one lens, and I didnt get the leak on an image where I know I shot with the tight board. So that came to mind rather late admittedly, though I agree it does look more like a pinpoint leak.

The camera is a brand new Gibellini Bellatrix, and they've been great about it. The've offered to take it back under warranty and make sure everything is good to go, but I am currently just trying to avoid that whole process as I'd have to ship it to Italy.

[Fred L]

I'm wondering the the holder was seated properly ? Your image wasn't cut off so it may have gone in most of the way, but not enough to engage the rib lock. that's my guess...

[John Layton]

A couple more things you might try: one is to place your holders onto a known flat surface to see if any are warped. Another is to remove the lens board, insert a holder about halfway (preferably outdoors in bright light), wrap a dark cloth over your head, and peer into the camera as you continue to slide the holder into position. Give yourself a couple of minutes under the cloth to become dark-adapted. Now, check carefully for leaks around the holder's perimeter. Then try lifting the holder backwards from its entry side...and see how much back-pressure is needed to allow light to enter - then note, just as you begin to release the pressure, if the last bit of light is finally (and thoroughly) extinguished. Then slide the holder partway out, and then back in again...to see if every bit of light is extinguished.