What is the difference between 100 ISO film and 400 ISO film?

[jp498]

I think tmax 400 and 100 act very differently in their results if you change only the exposure for a given scene and use the same developer, camera, lens, etc... Something about the curves, color sensitivity, contrast... They are different films that share the tmax name and Kodak high quality. 100 seems a little flatter, suitable for copy work but can also be made super contrasty as a substitute for tech pan. Both are quite versatile for various uses.

100 use can use caffenol-C without fogging. There are caffenol variants that can be used with higher speed films though.

In large format, I think (not speaking with certainty), Tmx has a uv blocking layer and tmy2 doesn't, and this is useful for alt process printing which require uv or sunlight to happen.

Few need the higher detail of tmx in LF (or MF for that matter). I am pleased with the fine grain of tmy2 and use that for just about everything in MF and LF.

[markbarendt]

A little off topic here, but why is there no 800 speed B&W film? I've always been curious about that.

Actually there is!

Kodak TMax P3200

http://www.kodak.com:80/global/en/pr...6/f4016.pdfsee page 19.

Ilford's Delta 3200 is actually an ISO 1000 film.

http://ilfordphoto.com/Webfiles/201071394723115.pdf

See page 1

These films are named "3200" but that isn't their ISO speed.

[Rolleijoe]

A little off topic here, but why is there no 800 speed B&W film? I've always been curious about that.

Funny you should ask. Back in the '80s-'90s Foma used to make an 800 speed film, and it was really good. But that was before it's become the household name they are today.


Required no special processing, either.

[kiku]

And two stops.

The OP said that!

[2F/2F]

A little off topic here, but why is there no 800 speed B&W film? I've always been curious about that.

Delta 3200 and T-Max 3200 are both ISO 1000 speed films. That is only one notch faster than 800.

My question would be, "Why are there no b/w films faster than 1000?" Some "true" ISO 4000 or 8000 speed film would do me wonders with a lot of my shooting.

[Photo Engineer]

You approach a limit in terms of keeping. The faster the film, the worse the keeping due to heat and radiation sensitivity.

Actually, a 24000 speed film is possible as posted here on APUG, but it has not gone forward.

PE

[2F/2F]

Yes, I would expect to buy it fresh all right!

[Newt_on_Swings]

I would love a 24000 speed film, then again im already too cheap to spring for 3200 speed lol