Film shifting in holders

[Andrew O'Neill]

I put a very small piece of thin double-sided tape in the centre of the holder to keep film from shifting or bending. A blast of canned air presses the film onto the tape. I find this to really help with 8x10 film.

[Julio Fernandez]

Michael, you got it! Film can navigate a little within the holder and the gaps between the lips and the septum are often too large and out of spec, meaning that the film can readily move in 3D. One reputable brand of film holder I know fails the ANSI spec with regards to this gap, although otherwise this a very nice holder. If the film seems quite easy to load and unload the film holder is probably out of spec -even those may be the holders you love loading!!!. A larger gap in the loading channel allows the the film to travel and might also lessen sharpness as it allows for larger changes in the film's plane. Additionally, photogs should remember that films are an unbalanced construction. The emulsion responds differently to changes in humidity and temperature than the backing. Taking film from an area of low humidity (air conditioned home) to the more humid outdoors will cause the emulsion to expand and develop a convex curvature looking at it from the emulsion side. The opposite will happen if the change is the reverse. A concave shape will restrain the film's movements but a convex shape will not. Humidity changes while shooting will result in ghosts. Pre-conditioning the film to the environment will prevent the change from happening at the worse moment. Tapping the film in the direction that it will reside within the camera seems also a good idea.

[Andrew O'Neill]

Gee....am I the only one using double-sided tape??

[jarrod connerty]

Does this mean that one should tap the holder so that the film is settled towards the side that is closest to where one removes the darkslide, or towards the side that is closest to where one loads and unloads the film from the holder?

[Jan Nieuwenhuysen]

Jarrod, the idea is that you tap the holder to settle the film on 'the bottom' of the holder to prevent gravity from pulling the film down just when you are making the actual exposure. Which side of your holder is 'the bottom' depends on whether you take a portrait or landscape oriented shot. Just before you insert the holder, see what side of it will be under, in other words: will be 'the bottom'. Then gently rap that side of the holder against your palm a couple of times to make sure the film sits on that side of the holder. Insert the holder and make the exposure. Hope that's clear.

[jarrod connerty]

Thanks Jan, that's clear as something that's clear(I'm not very good with analogies). Cheers.

[QT Luong]

Note step 11 of

how to operate the LF camera. I've tried double sided tape once
for a shot that required a 15min exposure. The problem is that removing
the film from the holder afterwards is very tricky because the rails prevent you from lifting the film up.