Developing Aviphot 200-derived films (Catlabs 320, Rollei IR400, etc.)

[pbromaghin]

I'm looking for development advice. I admit it, I'm cheap, or maybe just not completely stupid. I like Rollei IR400 but B&H has the Catlabs 320 version at about 1/2 the price, so I'm going to get that.

I use it only as infrared with a R72 filter and have generally incident metered at 400 iso and added 6 stops. I currently use D76 replenishment.

The Massive Development Chart lists several different times for the different versions in D76 at stock strength:

SuperPan 200 14:00
Retro 400s 10:30
IR400 6:00
Catlabs 320 6:00

Suggestions?

 

[Don_ih]

I use pyrocat hdc at 14 minutes. I was using a special routine with D76 1:1 and a second alkaline bath but pyrocaty hdc is better.

 

[qqphot]

i wish i could just buy a couple hundred feet of aviphot 80 for cheap and not have to deal with all the mystical secret rebranding resellers. it's not my favorite film but it's pretty versatile and would be nice to have a bunch in the freezer. I actually kinda like it in hc110.

 

[bluechromis]

I'm looking for development advice. I admit it, I'm cheap, or maybe just not completely stupid. I like Rollei IR400 but B&H has the Catlabs 320 version at about 1/2 the price, so I'm going to get that.

I use it only as infrared with a R72 filter and have generally incident metered at 400 iso and added 6 stops. I currently use D76 replenishment.

The Massive Development Chart lists several different times for the different versions in D76 at stock strength:

SuperPan 200 14:00
Retro 400s 10:30
IR400 6:00
Catlabs 320 6:00

Suggestions?

To meter sans filter at 400 seems high to me. These films are really Aviphot 200. As seen in previous threads, Henning Seger says that IR films are rated differently than conventional films. When used as pictorial films the speed is half that of rated speed. So that gets us down to a speed of 100. But they excessively contrasty films, so it may make the most sense to rate it less than 100. This makes using manufacturers' suggested developing times difficult unless they post times for > 100 E.I. It would be best to do some tests.

 

[MattKing]

To meter sans filter at 400 seems high to me. These films are really Aviphot 200. As seen in previous threads, Henning Seger says that IR films are rated differently than conventional films. When used as pictorial films the speed is half that of rated speed. So that gets us down to a speed of 100. But they excessively contrasty films, so it may make the most sense to rate it less than 100. This makes using manufacturers' suggested developing times difficult unless they post times for > 100 E.I. It would be best to do some tests.

For clarity, the reason that these films aren't rated using the same approach as most pictorial films isn't because they have some sensitivity into the IR region, it is because they are designed for aerial photography, which means their standard development targets involve a higher gamma/contrast index.
If they are to be developed to a more normal gamma/contrast index that is more suitable for most pictorial use, they need to be exposed with your meter set to a lower EI.

 

[Klaus_H]

I do use IR400 / Superpan 200 with a RG715 / R72 Filter at 6/9° ISO.
The measurement is carried out with a handheld light meter in light metering mode.

The films are developed at 20°C in Pyrocat-HD 1+1+100 in 14 Minutes using a Heiland TAS filmprocessor.

 

[Oldwino]

The CatLabs version, rated at 160 in Diafine, has been a pretty bulletproof combo for me.

 

[bluechromis]

For clarity, the reason that these films aren't rated using the same approach as most pictorial films isn't because they have some sensitivity into the IR region, it is because they are designed for aerial photography, which means their standard development targets involve a higher gamma/contrast index.
If they are to be developed to a more normal gamma/contrast index that is more suitable for most pictorial use, they need to be exposed with your meter set to a lower EI.

Henning also pointed out that when looking straight down in an aircraft, objects on the ground may have little shadow and little contrast. So, military users wanted films with strong contrast to improve the definition of surface features.

 

[pbromaghin]

I do use IR400 / Superpan 200 with a RG715 / R72 Filter at 6/9° ISO.
The measurement is carried out with a handheld light meter in light metering mode.

The films are developed at 20°C in Pyrocat-HD 1+1+100 in 14 Minutes using a Heiland TAS filmprocessor.

I've been metering at 400 and adding the stops because my former light meter topped out at around 15-25 iso. It came out equivalent to 6 iso. I just checked my new meter and it will go to 6, so from now on there will be one less chance for error.

Per the MDC, your 14 minutes with Pyrocat corresponds to 14 minutes in D76 stock. A comparison between rolls I've processed at 6 and 10 minutes shows the 10 minute to have much better contrast. I'll try 14 for the next roll, probably today.

Edit: i took another look at the 10-minute film on the light box and it looks about how I want it.