Testing Film Holders

[Fungus]

I just bought a bunch of used 4x5 film holders on eBay. What’s the best way to test these for light leaks?

[diversey]

Photo paper.

[gypsydog]

Buy a box of cheap CatLabs X80 film, load the holders and expose them to prolonged light, develop film keeping track of which holder it came from.

[popdoc]

Photo paper


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[Vaughn]

Number the holders, load with film, and start using them. Note any fogging when developing the film.

Holders have to be pretty beat-up to leak light...and unless you have a lot of time on your hands, I would not bother testing. But photo paper in bright light would be the way I'd go about it. But while you are at it, stick a new-to-you holder in the camera in the sun, stretch the bellows out, and leaving the lens closed, remove the darkslide for 15 minutes, and see how your camera is fairing.

[John Layton]

photo paper is not sensitive enough (IMHO)...gotta be film!

also see if the holders lie flat when placed on a flat surface with the ribbed spline hanging free over the edge. If perfectly flat...great! If not, then insert into film holder and look back into bellows (lens removed) under dark cloth while bright light shines obliquely towards back end of camera and make sure that film back spring tension is more than enough (reaching back to push the projecting end of the holder backward until light just starts to enter) to straighten out those holders!

[Tin Can]

If wood, warpage is common in not stored flat or UP

Be careful how any DDS is stored

[jnantz]

fungus

get some bookbinders tape, you might have to re-tape the hinges

[paulbarden]

Number the holders, load with film, and start using them. Note any fogging when developing the film.

Holders have to be pretty beat-up to leak light...and unless you have a lot of time on your hands, I would not bother testing. But photo paper in bright light would be the way I'd go about it. But while you are at it, stick a new-to-you holder in the camera in the sun, stretch the bellows out, and leaving the lens closed, remove the darkslide for 15 minutes, and see how your camera is fairing.

+1

[Alan Townsend]

fungus,

1. Examine and clean the holders using compressed air. If any are really sticky, soak in warm dish detergent/water, rinse and dry. Cull crummy ones.

2. Test with cheap xray or ortho litho films or enlarging paper. Place outside in shade and leave for ten minutes or so on each side. A little longer with paper. Process and check. Or just use them and see if they work OK.

3. Using a shim that is 3/16 inch thick (.1875 in.), check this critical dimension to ensure correct focus. Many newer film holders may be off. Older ones not so much. Put the shim against where the film goes, and make sure the front of the holder is in the same plane as the top of the shim using a straight edge and feeler gauge if you have one.

Lock, and load. I mean unlock, load, then lock and go shooting.