View Full Version : Efke IR820 Sheet Film (4x5) in Pyrocat HD

Barry Wilkinson
26-Jul-2017, 03:21
I am about to process my first sheets of Efke IR820 Sheet Film (4x5) in Pyrocat HD. As this film is no longer available I am trying to get close results with minimal sheet losses. Can anyone give me a 'ball park' time for this combination. I use Pyrocat HD semi-stand, usually continuous inversion for one minute, the four inversions every three minutes. TIA


Maris Rusis
26-Jul-2017, 16:02
I've shot hundreds of Efke IR820 negatives and found that development is very non-critical as long as it is enough. It is impractical to target an exact density and contrast in the negative because film exposure itself is a bit of an unknown. Setting shutter speed and f-stop on the camera and doing "best guess' metering does not guarantee how much infrared radiation the subject matter is emitting and how much will hit the film.

Barry Wilkinson
27-Jul-2017, 02:02
Thank you Maris it seems I have a lot to learn, hopefully before I run out of film! I also undertook some online research on exposure and found that that different users were getting wildly different film speeds. In the end I used the 'Sunny 16' method, I will find out in the next day or so if it worked. I think I will try a developing time longer than my usual for other films, trial and error I suppose.

Barry Wilkinson
28-Jul-2017, 01:10
For anyone interested...

Well, I found that development of this film is not so difficult, as Maris said 'as long as it is enough'. I don't know yet if Pyrocat HD is the ideal developer for this film but I do have some images. I tried Pyrocat HD 1+1+100 for 14 mins and 18 mins (agitation for the first minute and four inversions every minute) and do not see much difference with each. There is no fogging in the film margin on either. However I have not bothered to take any density measurements as I underexpose the film by some margin. Something new to learn! I exposed the film in the UK summer sun at 1 ISO with an 89b filter.

28-Jul-2017, 04:39
I had the same problem with underexposure of this film in sheet format. I had good results with the 35mm version rated at 4.5 asa and an IR 720 filter. With sheets, however, I was badly underexposed. I haven't tried again, but will do so in the near future. I'm also in the U.K. Is the 89b filter similar to the IR 720? Some filters have too high a cut off point for this film.

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Barry Wilkinson
28-Jul-2017, 15:50
Hi Alex,

The 89b works at 695nm, so slightly lower than the 720nm. I think you may have hit the nail on the head, the problem is the films reciprocity? Maybe it differs in each format? I will try a larger range of exposures when I get the opportunity to get out again (and see some sunshine!). Thanks, Barry