When I look at the choice of films i used - I can't say that I really knew so well, why I chose a certain film... I believe i used an Agfapan 100 film for this longtime exposure... and it was something like several minutes. The term "reciprocity failure" also known as "Schwarzschild Effect", was unknown to me.

It means, in low light, a film's sensitivety is falling, because the silver crystals can't keep the photon (it needs two in order to make a latent stable silver grain). So, in low light, your ligh meter perhaps says 1 minutes exposure time - but in order to get a good exposure, you might have to expose the film for a whopping 30 minutes. Otherwise it will be underexposed...

Well, in hindsight, i may not have mattered, because a black and white ISO 400 film can actually be less sensitive than a ISO 100 film at night during longtime exposures... Each film has a different Reciprocity failure... Best in class is Fuji Neopan Acros 100 - which is barely affected by this phenomena - while most other films are.

Especially Kodak Tri-X, All Ilford Films and Hungarian Foma films. They have huge reciprocity failures - so you have to really make very long exposures in order to compensate. And i am talking about light levels that are very low, where you would need 2 minutes or longer, according your light meter - but likely need 20-60 mintues in reality.

Anyway, Jonas stood there for a very long time. And the negative was still pretty thin. Albeit that is not problem now 32 years later, digitally lifting the shadow areas of the negative, even when they are very thing, one can still pull details out. That's pretty cool actually. But I also have printed this negative earlier, on paper what lifted the shadows a lot (the legendary, extremly shadow seperating Emaks K888 paper, but also an older ORWO paper something with 111, which was absolutely amazing).

Those papers made shadow details become "airyer", by lifting them a bit higher on the tone scale. A extreme short toe paper, so to speak.

 

A tiny flash

The the image above, I did actually use a weak flash light - because I knew, that the exposure of the film with only the faint light, wouldn't be enough... so I fired a tiny helper flash, in order to get a better (longtime) exposure. And yes, I it did help. I did not mean to use the flash as the main light - but only to lift the overall density on the white clothes.

 


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