Film base + fog readings

[Michael Jones]

I did a quick search and found several threads discussing b/w films with low base density + fog, but little empirical data. I was wondering if anyone has conducted testing, BTZS or otherwise, and has some results for base density+fog on B/W sheet film to share? I’d like to discover the clearest [traditional] film base reading. If you could describe the developer and agitation style, that would be a plus. Thanks.

Mike

[ic-racer]

Here are some typical values I have recorded:

Tmax 100 4x5 about 5min in Tmax Dev, in Expert drum 24C = 0.10
FP4+ 8x10 about 5 min in Tmax dev, in tray = 0.10
Arista 100 8x10 about 5 min in 1500 rotary drum 24C = 0.21

[dng88]

I thought it depends largely on your setup. If the dark room light leak a bit (I use rubbish bag as the dark cloth), it can go a bit higher than the figure ic-racer quoted. (I guess ic has a better darkroom than mine.)

[SamReeves]

Pretty much the same for me as well. Jobo CPP-2, D-76 1:1, 70°F:

Tri-X @ 6:00 0.12
Fompan 100 @ 6:55 0.10
Ilford HP5 @ 6:45 0.13

[Henry Ambrose]

Hi Mike,

No scientific testing here on my part but I suggest you look at Acros as a candidate for "clearness".

A couple of questions:

I don't know exactly what you mean by "traditional".

What's the desired result you're looking for once you find the answer?

Henry

[Marko]

Also, do you have a particular developer you're looking at? Rodinal, IME, seems to consistently give the clearest base, but not by much.

My lowest was FP4+ in Rodinal 1+50, agitation by inversion, fb+f = 0.07

Delta 100 in Rodinal 1+50, inversion, fb+f = 0.10

Tri-X 320 in D76 1:1 Expert drum, rotation fb+f = 0.11

HP5+ in D76 1:1, inversion, fb+f = 0.12

All at 68°F and same fixer.


Marko

[Andrew O'Neill]

HP5+ Pyrocat-HD 2+2+100 BTZS tube fb+f = .11

[Michael Jones]

This is great and exactly what I was wanted to know.

By " traditional" I meant "film," not inkjet or other process. I generally use Tri-X or HP5+ and pyro.

I'm looking for clearest base and then the b+fog to see the impact of developerment.

Anyone have any readings of Acros?

Thanks again.

Mike

[sanking]

This is great and exactly what I was wanted to know.

By " traditional" I meant "film," not inkjet or other process. I generally use Tri-X or HP5+ and pyro.

I'm looking for clearest base and then the b+fog to see the impact of developerment.

Anyone have any readings of Acros?

Thanks again.

Mike

B+F of Acros is very low, about log 0.06-0.08 with fresh film and normal development times.

Sandy