Luminous Landscape Forum

Equipment & Techniques => Medium Format / Film / Digital Backs – and Large Sensor Photography => Topic started by: marc gerritsen on September 20, 2006, 10:19:48 am

Title: film/digital sensitivity
Post by: marc gerritsen on September 20, 2006, 10:19:48 am
Just took out my old trusted minolta V lightmeter to do some spot metering.
I thought that my digital Hasselblad would read the light more or less the same
as the minolta but I had to put my lightmeter at 20 iso when my Hasselblad
was set at 50 iso for the same speed and light.
Is my suspicion now finally confirmed that my digital is less sensitive to light as film?
Have you guys done similar calibrations and if yes, are your settings comparable?
just wondering.
Marc
Title: film/digital sensitivity
Post by: damien on September 20, 2006, 07:14:09 pm
Film speed was always a strange issue to explain. The system of deriving an ISO value was determined by the threshold at which a certain level of reaction occured in the emulsion. It had very little to do with what setting to use to obtain a good exposure. Hence I used to shoot my Velvia at 40 ISO and Provia 100 at 125. With digital backs the point at which shadow detail is rendered happens earlier due to the higher dynamic range hence manufacturers have to use the word "equivelent" when quoting ISO values. In practice I'm using similar exposure settings that I used to and my Nikon and Phase back correlate. I sold my Minolta spotmeter when I went digital as it was rendered useless. I now asses exposure using the actual picture. I hope this helps.

Damien.