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Efke IR820 Dev Times with Pyro Developers

Tumbles

Member
Joined
Apr 20, 2016
Messages
140
Location
SF Bay Area
Format
Med. Format RF
I've decided to start shooting my stockpile of Efke IR820. I'm wondering if anyone has dev times for Pyrocat and/or Obsidian Aqua along with an agitation procedure? I looking for something I can use with a regular Paterson tank, rather than a rotary processor. With my limited supply I really don't want to end up sacrificing some rolls for trial and error.

This guys stuff is what sold me on these combinations:
https://www.flickr.com/photos/mat4226/albums/72157629752474613

I think the dilution of 2:2:100 that he lists suggest that his times are for rotary processing. I wish people would post the agitation procedure more often with the times for Pyrocat. It's hard to tell if they're for rotary, regular or minimal agitation.

I didn't see any times listed for Obsidian Aqua.
 
I've always used 1+1+100. 9:30. 21C. EI 6. Continuous agitation in BTZS tubes. I also have reciprocity data that I generated for this film years ago...
 
Andrew O'Neill said:
I've always used 1+1+100. 9:30. 21C. EI 6. Continuous agitation in BTZS tubes. I also have reciprocity data that I generated for this film years ago...
Click to expand...

Hi,

exposed my last three 120 rolls of IR820 last month...
It needed quite a lot of Schwarzschild compensation, I used
1 stop for 1 sec,
2 stops for 10 sec,
3 stops for 100 sec.
Were your's similar?

It lookes very nice with my Pyrocat (the Windisch formula, similar to Obsidian Aqua...)
E.I. was only 1 due to the narrow 780nm band pass filter I took.

Best
Jens
 
Last edited:

1 sec metred I only give 1/3rd stop more exposure.
10 sec = 3x more or 1 2/3rd stops more
100 sec = 12x more or 3 2/3rd stops more
 
Andrew O'Neill said:
1 sec metred I only give 1/3rd stop more exposure.
10 sec = 3x more or 1 2/3rd stops more
100 sec = 12x more or 3 2/3rd stops more
Click to expand...

Ah, I see - thanks Andrew.
I should have bought more of this great film...
 
Jens Hallfeldt said:
Ah, I see - thanks Andrew.
I should have bought more of this great film...
Click to expand...

I know, right??!! I have one, 8x10 sheet left... ONE! But at least I have a 50 sheet box of 4x5 in the freezer. I'll keep it there until next Summer... I also have about 75 sheets of Rollei IR. Not as IR sensitive as Efke, but at least grain is sharp and fine.
 
So, 9:30 with continuous agitation at 21C. That should translate to around 12:22 at 20C with standard agitation: continuous inversions the first minute, and then 3 or so inversions every minute. This is what I got out of the massive dev chart temp/time converter. I'm not sure if this is the best way to figure this out.

I've always shot this film at ISO 0.75 with a 720nm filter. The first time I used it, I tried ISO 6 and hardly anything showed up on the negatives.

These are the times I have written down for the reciprocity failure:

0:01 = 0:02
0:02 = 0:04
0:04 = 0:08
0:08 = 0:24
0:15 = 1:00
0:30 = 3:00
1:00 = 8:00
 

The famous last sheet! Here only 12 sheets of HSIR in 4x5" (waiting for the perfect use) and some SFX200 in 120.
 
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