Film grain sizes for different ISOs?

**Powow** · 07-01-2008, 12:07 PM

I'm working on a project and I need to know how big the grains are in different ISO speed films. I've been having a bitch of a time hunting this info down, all I know right now is that ISO 100 ~ 6 microns, and ISO 800 ~ 17 microns.

I'd like to know more ISO vs. grain size pairs, at least ISO 400 and ISO 1600 as well. A nice chart that has ISO in increments of 100 would be just awesome though

I realize these might not be completely determined by eachother, but all I need is a typical/average grain size for a given ISO.

**bklyn** · 07-01-2008, 12:09 PM

Did you try http://photo.net/ ?
If you can't find the answer there, try asking it there.

Hugh Conway · 07-01-2008, 12:12 PM

http://aic.stanford.edu/sg/emg/libra...resolution.pdf

http://www.kodak.com/global/en/profe....jhtml#1004311

Kodak tech pubs are a wealth of information.

**Powow** · 07-01-2008, 02:18 PM

Originally Posted by Hugh Conway

http://aic.stanford.edu/sg/emg/libra...resolution.pdf

http://www.kodak.com/global/en/profe....jhtml#1004311

Kodak tech pubs are a wealth of information.

The stanford link is awesome, thanks!

I guess the reason I had such difficulty finding this stuff is because most of this documentation is on the relationship with print grain, which I know nothing about.

I will start looking up the relationship between film grain and print grain.

I'm a JONG with regards to this stuff, I'm just a computer programmer that happens to be working on a project related to film.

**summit** · 07-01-2008, 02:21 PM

It depends on the emulsion, exposure, the developer, and the development, not just the rated sensitivity.

**Powow** · 07-01-2008, 10:53 PM

Agreed, but isn't there a general trend of ISO ~ grain size? I've found quite a bit of literature already that states this much. I found a dozen ISO 100 films that are all within 6-10 microns, whereas I found a single value for ISO 800 film at 17 microns.

All I'm trying to do is give people an approximation of what kind of ISO they are simulating, so all I need is some ballpark values. Hell, there is way more error in the rest of the system to accurately declare the grains as x microns anyways.