Agfa APX 25 development time?

Bill Burk · Oct 14, 2017

I am planning to develop a roll of Agfa APX-25 and looking for time in D-76 1:1 (or stock) at 20-degrees C

For comparison of the problem I anticipate, I found Agfa APX-100 time 9.5 on the Massive Dev chart, but my tests revealed it required 19 minutes to reach 0.59 CI.

I chatted with PE about the finding and he suggested that a phenomenom, gelatin hardening, may be responsible for the much longer than expected development time.

So I expect to find any published time will be too short.

Has anyone recently developed any of this stuff and find out a good time?

For comparison, I developed a roll of Rollei Pan 25 in D-76 stock for 9:30 and was happy with the results, but that film was fresh.

Whatever I do, I'll include a sensitometry test strip and will evaluate the results, so I can tell you what the outcome was...

john_s · Oct 14, 2017

This is a screen shot of part of a page from Ilford Film Chemical Manual probably from 1995 judging by its printing code.

john_s · Oct 14, 2017

Sorry about the format of above post. The ID-11 time probably a good guide to D-76.

Bill Burk · Oct 14, 2017

Thanks john_s I can figure something out from there

gorbas · Oct 14, 2017

Interesting question Bill!? In the next few days I will have to develop Agfapan 25 I recently got in 35mm. Most likely I will use Rodinal 1:50. Will keep you posted! My question is: did Agfa changed anything in film characteristics between Agfapan 25 and APX-25?

john_s · Oct 14, 2017

re Agfapan 25 and APX25. This might be of some forensic use, sent to me by Agfa in the days when these questions were answered by post! Yes, I have been around for a while. Bear in mind that old film isn't going to work just like it used to (like us!)

gorbas · Oct 14, 2017

Thank you John_s! I'm thinking of using Rodinal 1:100, 20C, 15min

Bill Burk · Oct 14, 2017

I probably will do 17-19 minutes in D-76 1:1 because I see most times are similar to APX 100 (or 2 minutes less)... and I found same vintage APX-100 “slightly” under target at 19 minutes. It’s from a bulk roll 35mm so once I get it I’ll have a couple more rolls to shoot.

Again, mine is 20 years expired so I don’t expect published times to work. By the way, the APX-100 had no measurable fog and achieved 64-80 speed.

destroya · Oct 15, 2017

I've never done apx 25 in D-76, but I just developed 20 rolls of apx 25 in 120, 14 using rodinal 1+50 for 10 min and 6 using pyro-mc 1+100 for 15 min agitating every 3 min. really hard to tell them apart, but boy are they a thing of beauty! the film was shot at an EI of 16 with an ex date of 5/05

john

Bill Burk · Oct 16, 2017

I find it amusing that the pictures are from a local festival called the "Fog Fest"...

Because the fog was pretty bad.
Base measures 0.25

15 minutes D-76 1:1 68-degrees-F
Base+Fog = 0.42
CI = 0.65
EI = 12

24 minutes D-76 1:1 68-degrees-F
Base+Fog = 0.44
CI = 0.67
EI = 16

gorbas · Oct 16, 2017

Hi Bill, I just processed my first test with Agfapan 25 expired in July 1989. I have no idea how film was stored before got to me. I used Agfa Rodinal 1:100, 20C, 13min. Run test exposures at 25, 12, 6, 3 iso. There is a minimal fog around perforations, middle part of the film to my eye looks OK. My next test will be at box speed andI could reduce developing time to 10 or 11 min. In some Agfa material from APX time they had time for Rodinal, 1:100, 20C, 15 min. So I did not experience your problem with need for prolonged developing with this particular film.

ic-racer · Oct 16, 2017

Bill Burk said:
I am planning to develop a roll of Agfa APX-25 and looking for time in D-76 1:1 (or stock) at 20-degrees C.

This is where I get out my sensitometer. Fire off a bunch of strips and process them. Look for the one with (in my case) 0.75 slope.
Added benefit (your sensitometer is calibrated, yes?) you can find out how really slow the film will be if one of your curves fits the ASA triangle. I'm guessing 12.

EDIT: Maybe you only have ONE roll. I'd preserve the leader (don't expose to light) and cut some thin strips that just fit over the step wedge.

gorbas · Oct 16, 2017

Ic-racer, how big is your sensitometer? What kind of shutter it is using? Never saw one outside movie film lab.

Saganich · Oct 16, 2017

I have the following in my notes and a full brick in the fridge. Not surprised to see 19min at a 1:1 D76. I develop in D23 at 12 minutes 1:0 and it's looks about right but I never made formal measurements.

AGFA APX-25 HC-110. Dilution 1:41. 10 mins, 20C light agitation. Gamma 0.51. Curve was as linear as they come.

Bill Burk · Oct 16, 2017

ic-racer said:
This is where I get out my sensitometer. Fire off a bunch of strips and process them. Look for the one with (in my case) 0.75 slope.
Added benefit (your sensitometer is calibrated, yes?) you can find out how really slow the film will be if one of your curves fits the ASA triangle. I'm guessing 12.

EDIT: Maybe you only have ONE roll. I'd preserve the leader (don't expose to light) and cut some thin strips that just fit over the step wedge.

I've got the last part of a bulk roll, maybe enough for two more rolls of film.

I ran sensitometry strips along with a roll that I'd shot.

Both 15 and 24 minutes fit the ASA triangle (one above one below both within the 0.05 tolerance).

Due to the fog, I am getting speeds between 12 and 16. (my sensitometer is consistent, and I "calibrated" it over time by assuming TMY2@ASA Triangle=400)...

ic-racer · Oct 17, 2017

I'd say 80% of my practical sensitometry is looking for the slope, to find development times for unknown film/developer combinations. The time-honored "Control Strip" with an undefined X-axis.
The rest of my senstometry is just educational APUG fun stuff

For example my latest spreadsheet does calculate speed on a data-set, however, perhaps the more useful number is the little 0.562. I know that the film processed under those conditions will not print well in my darkroom unless I crank up the magenta.

BTW I have the spreadsheet do a least-squares regression on the first 12 points higher than 0.1. It does this automatically; I try to make it as objective as I can.

ic-racer · Oct 17, 2017

gorbas said:
Ic-racer, how big is your sensitometer? What kind of shutter it is using? Never saw one outside movie film lab.

The only one with a shutter is the Wejex, which has an incandescent lamp. The LED and Xenon units don't need a shutter.
https://www.photrio.com/forum/threads/the-great-sensitometer-shootout.95837/page-3#post-2003147

gorbas · Oct 21, 2017

Thank you IC-racer! They are smaller than I remember.

removed account4 · Oct 21, 2017

hi bill !

if you have dektol or ansco 130
mix some up 1:6 and process your iflm
for about 7 minutes. a130 @72º, dektol @ 68º

Bill Burk · Oct 28, 2017

I have to revise my EI upward. Found I was using my old chart. It’s closer to 20 and 25. So the fog didn’t hurt speed as I originally thought.

Bill Burk · Oct 28, 2017

I revised my graph paper so I won't make that mistake again. I also found a previous run of APX-25 where the B+F was unexpectedly high and I noted to myself that it might be an issue of dye removal... recommended myself to use stronger fixer/longer washing next time...

So maybe I don't have a bad issue with fog. I certainly didn't lose speed.

Agfa APX 25 development time?

Attachments

Privacy & Transparency

Privacy & Transparency