Testing unknown films

[Greg]

A while back acquired many boxes of mostly 11x14 film from our State's surplus store for just a few dollars. Among them are:

PREMIUM HD NEGATIVE FILM
TYPOAQUE TR-DO film
KODAK BIOMAX
KODAK Special PX-2836
Kodak Precision Line
Agfa TP5F (lot of boxes of this film)
2 unlabeled (but the same looking) boxes

So now I have time on my hands to try out these films to see if any are even useable. Was thinking of cutting up sheets of the films to 8x10, and also cutting up 2 dark slides so that I could make 4 different exposures on each sheet of film.

Shoot 4 exposures on each sheet at ISOs of 1.0, 4, 25, and 100.

Punching/notching the edges of the films to know which is which after precessing. Also shooting 2 sheets of FP-4+ as a known standards to compare the results of the other films with. Do this twice with sheets my "unknown" films, then process one batch in Rodinal 1:25 for 10 minutes and the other batch in Rodinal 1:100 for 20 minutes. With processing 4 runs using my JOBO 3005 tank, should be able to get some useable results/data.

Would very much welcome comments and/or suggestions before doing this.

Thanks

[Vaughn]

It will keep you busy! The KODAK Special PX-2836 sounds like an RC paper...Google search came up with some one using it for lumen prints.

Contrast might be high in many -- great for low contrast scenes!

[Mark Sampson]

Kodak Precision Line films were 1990s replacements for Kodalith; labeled "Rapid Access" for machine processing. I've extensively used two of them: LPF7 on a 7-mil base for making negatives, and LPD7 for direct positives, two stops slower. They are both very high contrast films, and you will not achieve continuous tones with them. There were a number of film variations on that theme, all can be tray-processed (you won't need the RA chemistry). I don't recognize any of the others, though.

[ic-racer]

Cases like this, a sensitometer is handy. You can zero in on the exposure index, before you go to the field. So your spread of exposure index tests can be more like 1/2 or 1/3 stops apart. E-bay shows 93 sensitometers currently.
You can also zero in on development time too.

https://www.largeformatphotography.info/forum/showthread.php?155726-Shanghai-8x10-100-Film-Test

[Greg]

PREMIUM HD NEGATIVE FILM - looks to be the promising
TYPOAQUE TR-DO film - "expose on lightbox 1-2 minutes" - forget this box
KODAK BIOMAX - is double sided Radiograph
KODAK Special PX-2836 - Vaughn, yes it is paper. Lumen prints with grandkids
Kodak Precision Line - Mark, will use like 2566
Agfa TP5F (lot of boxes of this film) - also looks to be promising
2 unlabeled (but the same looking) boxes - paper, not film

ice-racer - you mean densitometer? Have one but next few days 65 degrees and sunny so prefer to get outside

thanks all

[ic-racer]

Yes, one would also need a transmission densitometer to read the control strips.