Quote Originally Posted by marciofs View Post
I am saying that because wherever review I find in the internet they say Fomapan 400 is actually ISO (or better perfomaced) at 250 to 320 depending on the developer (250 for Rodinal). And I have read many posts complaining about issues with this film exposure and replies explaining it is because 400 is not the real ISO.

After reading that (in different pages) I was surprised I got a good exposure. And I was wondering if the data in digital truth is actually adapted to develop it at ISO 250, or if it was because I am used to over expose a bit so I just got luck.

This is a example of what I got: http://www.marciofaustino.com/upload...08865_orig.jpg
The real ISO is in the manufacturers data sheet for Formapan 400, the box speed in marketing hype to a degree.
The Formapan 100 data sheet also seems accurate, not tried Formapan 200 much.

Forma have provided the contrast, fog and ISO dependency for time and temp for three developers.

formapan 400 datasheet

Then you need an adjustment for your developer, meter/shutter and metering technique.
Digital truth is closer to 'Analogue Porkies'

Rodinal @ 20C 1+100 stand will be in the 250-320 range with low contrast, but you may not like the rendering, I set my Weston to 250. Pour in the Rodinal invert a few times and set the kitchen timer for 60 minutes. Id also temper the following solutions to 1C, cause the Forma is not as prehardened as Kodak or Ilford film.

Most of my shooting is high contrast.