Why 32 ?

[kombizz]

Moment ago, I was looking into the gallery, then I liked an image of Saby.

http://www.retouchpro.com/gallery/sh...33/ppuser/9039
Then I noticed that Saby wrote a short note about his image:

32bit file created from a raw by qtpfsgui, tonemapped, hue & saturation corrected by cs2

My question is about 32bit file. I would like to get more info about it.
What is the importance of 32? Why 32 and why not 16 or 64 or ....
Also what effect it would have on an image.
I would appreciate your explanation.

[Doug Nelson]

qtpfsgui is an HDR app, HDR files are 32bit. We have an HDR forum here if you want to investigate further.

[saby]

Hi kombizz,

I'm very glad to hear U like my picture, actually I wrote 32bit instead of HDR because we were talking about HDR at another thread - U can check as Doug suggested - and conclusion is the real HDR is made from several files and I had only one raw, so if we want to keep technicality clear than it's not hdr just 32bit file. One of my friend's been living in Iran for 10yrs and he liked that very mutch.

to answer y 32bit: radiance files are called as floatpoint tifs so 32bit needs and enough to store this mutch of the information of luminance instead of 8bit files whitch contains only integer numbers