Developing Rollei Superpan 200 IR exposed @ ISO 12? Times for XTOL and perhaps other developers?

[Helge]

Surprisingly, I haven’t been able to find any place that discusses or lists times and possibly dilutions for various developers for IR exposed Superpan 200 development.
Plenty of places lists box speed times and times with a slight push.
But none (that I can find) discusses IR specific ISOs.
Am I missing something?

I shoot my specific roll at 12 but might shoot the next at 25.
Any suggestions for times and dilutions?
I have XTOL and Rodinal at hand, so I’d prefer those two.

 

[Anon Ymous]

The fact that you exposed the film through an IR filter doesn't matter when it comes to development. Whatever time works to give you a reasonable contrast will also be fine.

 

[Helge]

The fact that you exposed the film through an IR filter doesn't matter when it comes to development. Whatever time works to give you a reasonable contrast will also be fine.

That was my initial thought. But reading talk and looking at the data sheet, the sensitivity is significantly less at IR wavelengths, and you are only using a sliver of the films spectral recording potential.
Surely that has to play a part in how you develop?

 

[Anon Ymous]

Nope, it doesn't. It's only relevant during exposure. There is no "filter factor" for IR filters, the quantity of IR radiation is not guaranteed at any time and that's why it's a good idea to bracket your shots. As long as you have adequate exposure, the "normal" development time is fine. If you didn't expose enough, then your results will be sub-optimal anyway.

 

[Helge]

.

Nope, it doesn't. It's only relevant during exposure. There is no "filter factor" for IR filters, the quantity of IR radiation is not guaranteed at any time and that's why it's a good idea to bracket your shots. As long as you have adequate exposure, the "normal" development time is fine. If you didn't expose enough, then your results will be sub-optimal anyway.

Thanks a lot man! You’ve been a big help

 

[Lachlan Young]

If it's useful in any way, the sea level EI without filtration of the various rebranded forms of Agfa Aviphot 200S is around 125.

 

[Helge]

If it's useful in any way, the sea level EI without filtration of the various rebranded forms of Agfa Aviphot 200S is around 125.

Why do you use exposure index instead of ISO in this context? And how was it arrived at?
No doubt you have a good reason. I’m just curious.

 

[Lachlan Young]

Why do you use exposure index instead of ISO in this context? And how was it arrived at?
No doubt you have a good reason. I’m just curious.

Because Aviphot Pan is designed to a specified Effective Aerial Film Speed (EAFS or ISO A) which has a different aim contrast index etc than regular ISO standards for still films designed for sea level use. Agfa give a range of useable EI's from 125-250 depending on altitude, light bouncing off the earth, the contrast you need & how fast you need to fly! It's also worth noting too that most aerial films are designed for huge high contrast resolution numbers at the potential cost of edge sharpness and RMS Grain (which can be pretty bad on aerial films - but is much less of an issue when you're using 12/24/32cm rollfilm!) - hence why some people see the spec'd resolution claims and start getting themselves in weird contortions about aerial films being supposedly 'better' than the films intended for ground level use. Both materials are designed for optimal performance in their relevant roles, which are quite drastically different in their qualitative imaging needs!

 

[Neil Grant]

...i think (along with many others) that most of the Rollei films are in fact re-purposed 'Aerial' film stocks. In practice, for general purpose, normal contrast continuous-tone photography they will 'seem' a lot slower than their box-speeds suggest. Guessing filter factors when true film speed is uncertain is inherently risky.
If a film is always used with a specific filter - then there's not really a filter factor, just a range of camera settings that will work under a range of photographic conditions.

 

[Helge]

Because Aviphot Pan is designed to a specified Effective Aerial Film Speed (EAFS or ISO A) which has a different aim contrast index etc than regular ISO standards for still films designed for sea level use. Agfa give a range of useable EI's from 125-250 depending on altitude, light bouncing off the earth, the contrast you need & how fast you need to fly! It's also worth noting too that most aerial films are designed for huge high contrast resolution numbers at the potential cost of edge sharpness and RMS Grain (which can be pretty bad on aerial films - but is much less of an issue when you're using 12/24/32cm rollfilm!) - hence why some people see the spec'd resolution claims and start getting themselves in weird contortions about aerial films being supposedly 'better' than the films intended for ground level use. Both materials are designed for optimal performance in their relevant roles, which are quite drastically different in their qualitative imaging needs!

Thanks! That’s interesting.
Seems you have access to a different data sheet than me.

 

[Helge]

...i think (along with many others) that most of the Rollei films are in fact re-purposed 'Aerial' film stocks. In practice, for general purpose, normal contrast continuous-tone photography they will 'seem' a lot slower than their box-speeds suggest. Guessing filter factors when true film speed is uncertain is inherently risky.
If a film is always used with a specific filter - then there's not really a filter factor, just a range of camera settings that will work under a range of photographic conditions.

So you’re saying that the only way to be sure is to experiment? I was hoping someone had done that for me. ;-)
The most common “Sunny 16 table” range values cited are the one coinciding with an ISO of 12 to 25.
So a filter factor of 16 with the standard R72, and that puts the base ISO of the film to be between 200 and 400.
Perhaps a bit high. But the spectral curve is rising towards IR and the results posted on Flickr and various fora seem good (though I have no way of knowing whether they could be better (yet)).

 

[Lachlan Young]

Thanks! That’s interesting.
Seems you have access to a different data sheet than me.

It's on pg4 of the main data sheet on Agfa's website.

I'm also now pretty sure that the main reason Aviphot Pan 20 & 40 have never been offered in 135/120 etc conversion by third parties is because they're only offered on the ultra-thin PE0 base - great if you need to fly an aerial camera to the edge of space with sufficient film for a long mission, not so useful in a camera not designed to handle film half the thickness of regular 135/120.

 

[Neil Grant]

So you’re saying that the only way to be sure is to experiment? I was hoping someone had done that for me. ;-)
The most common “Sunny 16 table” range values cited are the one coinciding with an ISO of 12 to 25.
So a filter factor of 16 with the standard R72, and that puts the base ISO of the film to be between 200 and 400.
Perhaps a bit high. But the spectral curve is rising towards IR and the results posted on Flickr and various fora seem good (though I have no way of knowing whether they could be better (yet)).

...where does the filter factor of 16 with r72 come from? I suggest you try one of these Rollei Superpan/ near ir films without any filter at all to get an ideas of 'baseline' speed. Box speed (200? 400? ASA) will show very little shadow detail - that's where we judge speed in negative materials. When I used Rollei ir400 with an r72 I treated as 4 ASA under bright sun.

 

[Helge]

...where does the filter factor of 16 with r72 come from? I suggest you try one of these Rollei Superpan/ near ir films without any filter at all to get an ideas of 'baseline' speed. Box speed (200? 400? ASA) will show very little shadow detail - that's where we judge speed in negative materials. When I used Rollei ir400 with an r72 I treated as 4 ASA under bright sun.

Well that’s the oft quoted baseline filter factor of R72.
Of course that is hugely dependent on the film. But you rarely will get underexposure.
People seem to get good results with settings for ISO 12 - 25.

 

[Sirius Glass]

With all infrared film I have found use the light meter set to box speed then adjust the exposure for the filter correction [R23, R25, R29, 720] and develop normally with your developer-drug of choice [I use replenished XTOL] produces great prints.