Efke IR820 in ADOX APH09

TiMo · 2012-05-11T04:55:54+00:00

Hat jemand einen Tip für mich, wie ich oben genannten KB-Film in oben genanntem Entwickler behandeln soll? Die Photos sind nicht sonderlich wichtig, weil es...

TiMo

Does anyone have any advice for me on how to process the KB film mentioned above using the developer mentioned above? The photos aren’t particularly important, as this is just a test for me to see how colours are rendered in IR. The ASA setting was 100 with a red filter (+3 stops). As I said, the negatives don’t need to be brilliant; I just want to get a rough idea of the film. On Digitaltruth, I’ve only found values for much lower speeds. Thanks and best regards, Tim

Olivinyl

Hello It’s simple. You’d probably set the camera’s light meter to 100 ISO, hadn’t you? Then you measured the exposure without the IR red filter, put the filter on, and adjusted the aperture by 3 stops. Then just work backwards: 100 ISO – 50 ISO – 25 ISO – 12 ISO. That’s your value! What sort of red filter was that? The Efke IR100, with a 720nm IR filter, works between 6 ISO and 3 ISO. So set the camera to 25 ISO and open the aperture by 2 or 3 stops. It may be that your film has underexposure of 1 or 2 stops. So shorten the development time if necessary. Best regards, Oliver

TiMo

Hi Oliver, But I don’t have any exposure times for this film and this developer. That’s why I don’t need to start shortening the times just yet, as I don’t have a baseline. Are you sure that development times scale linearly with ISO speeds? The exposure was measured using TTL. Best regards, Tim

Olivinyl

Hi Tim If you measured using TTL and the filter, why did you open the aperture after taking the reading? What sort of filter was in front of the lens? EDIT: Hold on! From what you wrote above, I understood that you took a TTL reading, then adjusted the aperture by 3 stops, and then screwed the filter on. It seems you left the filter on the lens, measured TTL and set the camera to 100 ISO. Is that right? So you must have performed the exposure on the film at 100 ISO as well. Oliver

TiMo

Hi Tim If you’d measured the TTL and the filter, why did you open the aperture after the measurement? What sort of filter was in front of the lens? Oliver

I didn’t open the aperture. The red filter has a factor of 8 (=3 stops).

Olivinyl

Hi Tim I understand that you didn’t open the aperture. So if the filter is 8x, which is 3 f-stops, it must already be an IR filter of 695 or 720! What ISO setting did you set your camera to? Did you take the reading through the filter on the lens (TTL)?

TiMo

Hello Oliver, It’s not a special IR filter. It’s a standard red filter, the sort you’d use for normal black-and-white film. The ISO is 100. The exposure was, of course, measured through the filter.

TR

The question here isn’t how to expose the film, but how to develop it. These are two different things. Exposure time controls the shadow detail, whilst the length of development controls the highlights and contrast. If you measure the light using TTL, especially in sunlight, you often end up underexposing anyway. If you’ve found development times for this film that suit lower speeds or higher exposure levels, then you can use those too (and perhaps extend them by a quarter of the time to be on the safe side). It’s a common misconception that longer development times compensate for underexposure. Development times that are too long ruin the detail in the highlights.

Olivinyl

Hi Tim I see, so a red filter, probably an R8/25 from Hoya/Hama – though in this case, ‘R8’ isn’t the 3x factor but the model number. In that case, you’ll need to develop the film at 100 ISO. As all development data refers to 3–6 ISO, I’d recommend a stand development in APH. 1+100 to 1+150 for 60 minutes at 20°C in a large developing tank with 500ml. That should do the trick.

TiMo

Hello T.R. and Oliver, I was actually just wondering if anyone has any reasonably reliable development times for this film and developer combination. The times listed on Digitaltruth for Rodinal and this film don’t seem to have been properly tested. Based on those, I would have set my development to 1+50 for 13 minutes.

TiMo

Ah, so a red filter, probably an R8/25 from Hoya/Hama – but in this case, ‘R8’ isn’t the 3x factor, it’s the model number. In that case, you’ll need to develop the film at 100 ISO.

Hi Oliver, It’s a Marumi filter. Filter factor 8.

Olivinyl

The question here isn’t how to expose the film, but how to develop it. These are two different things. Exposure time controls the shadow detail, whilst the length of development controls the highlights and contrast. If you measure the light using TTL, especially in sunlight, you often end up underexposing anyway. If you’ve found development times for this film that suit lower speeds or higher exposure levels, then you can use those too (and perhaps extend them by a quarter of the time to be on the safe side). It’s a common misconception that longer development times compensate for underexposure. Development times that are too long ruin the detail in the highlights.

That’s obvious, but when asked about development time, you first need to know how the film was exposed. In Tim’s case, the film was exposed at its nominal speed. By using the R25 red filter, I would give the film a 1/3 stop boost, i.e. set the speed to 80 ASA. @ Tim: You wouldn’t have had to waste an Efke IR820 on a ‘normal’ red filter. You could have achieved the same effect more cheaply with Agfa ASP 400S / Retro 400S / Superpan 200S etc., i.e. with superpanchromatic films. The real IR films only become interesting with filters from 695nm upwards. That’s when you’ll also reach ISO values of 6–1.5 What’s the model number of the Marumi filter? MC-R2? AGFA ASP 400S @ 200 ISO Xtol 1+2 15 minutes 20°C Hoya R8/25 red filter [ATTACHMENT NOT FOUND] Best regards, Oliver

TiMo

What’s the model number of the Marumi filter? MC-R2?

Exactly.

Olivinyl

What is the model number of the Marumi filter? MC-R2?
Exactly.

This filter is then the same as the 25A / R8 – light red Best regards, Oli