True ISO site

[Steveo31]

Hey Everyone, new to the site, and a little green to the LF world. So far I loooove it.

I also tinker in web development, and I was curious to see if the demand existed for a site for people to upload their tests of ISO and contrasts, etc. If so, I wouldn't mind getting a few people to take the project on with me and we can get a site going that's actually helpful, not just another blog.

Let me know!

Steve

[robc]

don't you mean E.I.

[Donald Qualls]

The problem I see with putting up a list of the film speeds people derive from their own testing is that you'll quickly find the results follow the classic Gaussian distribution: there'll be a cluster around the "consensus figure" and then folks distributed around it, probably at least one stop out in each direction (not counting outliers like the college student who tested Tri-X 320 at EI 16 -- until the instructor found he was loading it backward).

And in the end, none of it will be any great help for anyone who hasn't done their own testing. I develop differently than you do (I use high dilution, low agitation, and a long soak), and I probably get a higher film speed at the same contrast, at the cost of some increase in grain, along with compensation and slightly increased acutance (to me, that's a no-brainer choice, but that's certainly not everyone's preference). If Joe Photographer habitually processes to higher contrast than Jim Shutterbug, Joe will likely also find a higher film speed, unless Jim spot-meters by Zone principles and Joe uses averaging and compensation factors (and then they might run either way, depending *how* they apply their metering methods).

Bottom line, what you'd wind up with isn't likely to be any better than the generic advice to shoot the film at half its rated speed, and develop 20% less than the manufacturer's recommendation -- though it'll certainly attract a lot more eyeballs, if you plan to place advertising on the page... ;)