Efke 25 and XTOL

[JPD]

Here are my filter factors for Efke 25. I also included N development comps for them. The factors are to maintain a zone 3 density. Films respond differently. Please note that these have been field tested by yours truly. I've used them for years.

#47 6x give N+2/3 development
#58 4x N-1/3
#12 1.5x N+1/3
#15 1.5x N+1/2
#21 3x N+1/2
#25 4x N+2/3

Reciprocity... Development comp. is not necessary, as contrast remains the same for all curves.
1 sec none
2 sec none (you could give 1/6 stop but really not necessary)
4 sec give 1.2x (1/3rd stop)
10 sec give 3x more exposure
16 give 4x more
32 give 6x more
64 give 9x

When starting out with a new film, I using run these tests. When I learnt of its discontinuation, I bought a few boxes of 8x10. Now I only have one box left. Soon this data will be filed away, never to be seen again. A wonderful film!

Thank you. I have mostly used Efke 25 in 120 and shot them under different lighting conditions and sometimes using different filters, so I have just compensated for the filter factor from memory, taking the lower red sensitivity into account. I have a few rolls in 120 and 135 left in the freezer, and some sheet film in 9x12 and 6,5x9 that I'm saving for special occasions.

With 8x10 you could cover a wall with a print and still don't see the grain. Have you tried Adox CHS 100 II, and what do you think of it? It's also orthopanchromatic, but is more forgiving than Efke 25 & 50, and the grain is more like Efke 50 than the old Efke 100.

 

[Andrew O'Neill]

Thank you. I have mostly used Efke 25 in 120 and shot them under different lighting conditions and sometimes using different filters, so I have just compensated for the filter factor from memory, taking the lower red sensitivity into account. I have a few rolls in 120 and 135 left in the freezer, and some sheet film in 9x12 and 6,5x9 that I'm saving for special occasions.

With 8x10 you could cover a wall with a print and still don't see the grain. Have you tried Adox CHS 100 II, and what do you think of it? It's also orthopanchromatic, but is more forgiving than Efke 25 & 50, and the grain is more like Efke 50 than the old Efke 100.

Efke 25 is hard to critically focus in the enlarger!
I also use CHS 100 II, as well as CMS 20 II. The latter is a pain to use as finding a good developer other than Adotech is difficult. It's incredibly sharp, though. I do like CHS 100, though.

 

[braxus]

Efke 25 is one of my go to B&W films, as I still have a large stash of this film. Many of my past films were done in Xtol and it works very well with this film. I would use Xtol again if I was developing myself. I always shot the film at box speed of 25, regardless of lighting conditions. I have heard of using 50 ISO for daylight, but I never did that myself. Dont go below 25 ISO, as the warning for doing so with this film is true. It doesn't like being overexposed.

 

[Ai Print]

At some point I need to get to using my stash of this film, I think I have about 200 rolls of it in 120.

 

[Helge]

The whole thing with overexposing film of a certain age is overblown and misunderstood.

It’s for certain film, often after a test, only after it’s several decades old and only to get useable/interesting results. Not to get predictable and correct results.

When you generally get away with it, it’s often because there is still a lot of range and latitude left in film that is even a few decades old that has been stored well.
But you are really only just mistreating the material and would get better results by just exposing at box speed.
Maybe for development of B&W you can do minimal agitation or stand.

 

[Donald Qualls]

As I understand it, the origin of using a reduced EI for long-expired film is to get enough exposure to overcome the age (thermal, background radiation, chemical) fog. The fog acts as a pre-flash, and like a preflash, only exposure above the fog level will be visible after development. Since you can't know the fog level without testing, @Helge has it right -- it's really only a useful rule of thumb, not a genuine knowledge-based method.

 

[Helge]

As I understand it, the origin of using a reduced EI for long-expired film is to get enough exposure to overcome the age (thermal, background radiation, chemical) fog. The fog acts as a pre-flash, and like a preflash, only exposure above the fog level will be visible after development. Since you can't know the fog level without testing, @Helge has it right -- it's really only a useful rule of thumb, not a genuine knowledge-based method.

Moderate fog is really not much of a problem.
It’s quite easy to remove or attenuate. Either in development, in the darkroom or in post.