Jump to content
Gareth Blackstock

D.I.Y testing stock for sensitivity and fogging?

Recommended Posts


I am coming up to a decent sized project and I need to test my store of expired stock. I am intending on taking a few feet from each roll, exposing them in a uniform way, sealing them, and send them off to be processed.

My big question is: how do I expose them all uniformly? Do I sit the lengths on a table in a dark room and let off a camera flash? Would that over expose the high ASA stock?

The lab I use is a small one and I think they do not have facilities or space to do such a test. Normally I shoot 100 feet as a test and send it off to discern the condition of the stock I have remaining, but I have around 13 different film stocks and I suspect a few of them.

I also accept there will be quality of image issues, but as the project is not a big budget one, we are happy to work with what we have.

Any thoughts would be helpful...

Cheers, gareth

Share this post

Link to post
Share on other sites

some labs will just do a test by taking a couple of feet from each roll and developing it.  slap it on the densitometer and see what the fog levels look like.  That of course  will not show how much speed loss you have. BUT the labs often will do this for a good customer at a low rate.  (if you are lucky even free)

if you have a camera available you might be able to shoot a slate with grey card and grey scale, at box speed. include a number to identify each batch you are wanting to check and leave some unexposed  film so they can do a densitometer check for fog as above.   if you can load in the dark and cut off your samples in the dark, you might still be able to only use a few feet.

talk to them about how they want you to pack the samples as they would probably prefer to splice them by their own methods.

your lab may have other ideas of course, you don't want to end up paying for a minimum processing chage for each sample.



Share this post

Link to post
Share on other sites


Thanks for the info, after chatting to the lab I reckon the best course of action is to expose each 5 foot length in camera, focused on a sample card, like your suggestion, in average light, ie 5.6 irrespective of ASA, or light the sample to get the same exposure, then load the lengths into light proof box and send it in processing. Its going to be quite process but I will get definite answers on my film stock.

Thanks again,


Share this post

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Ritter Battery

    Just Cinema Gear


    FJS International

    Media Blackout - Custom Cables and AKS

    Broadcast Solutions Inc

    Wooden Camera

    Paralinx LLC

    New Pro Video - New and Used Equipment

    Visual Products

    Tai Audio

    Abel Cine

    Metropolis Post

    Serious Gear

    G-Force Grips

    Rig Wheels Passport


    Gamma Ray Digital Inc

  • Create New...