Tmax 100 - shot at 100 and 175 by accident

[batey_1020]

I was out shooting yesterday on a half used roll of tmax. I shot it at iso 175 by accident so i have pics shot at both 100 and 175 (the ones at 175 being more important to me).

I usually develope tmax 100 in id-11 1+1 for 9.5 min and 20deg.
I havent pushed film before and now i have this odd situation i havent come accross before either.
I have see times where the ASA is listed 100-200. Would this be for a roll shot at 2 different speeds? I would assume i should be loking at this for best results or maybe shorten the time slightly.

My thoughts would be developing it Id-11 1+1 at 20 Deg for 11.5 mins?

 

[Fawley]

It kind of depends what you have on the roll and how you tend to expose. (Many people intentionally error to overexposure). Increasing development to accomodate the 175 ASA film will mainly have the effect of raising the values of the mid and bright tones, so if having bright and possibly some blown highlights is a big concern you might want to lean to the 100ASA development. I know if it was me, I would develop for the 175 ASA (I like a lot of tonal separation in the mid range anyway). Are your subjects mainly high contrast or low contrast? If high contrast, develop more for 100 ASA.

 

[bigeye]

Ilford lists 11mins, 20deg@1:1 for Tmax 100 (@100). I've seen 12 mins as the push time to 200 on the web.

So, yes, I'd just add ~30 secs (11:30) or so to split the diff. You're only off by a bit over a 1/3 stop @ 175. I wouldn't worry too much; it's tolerant stuff.

- Charlie