shot at the wrong speed

[Kat]

Just a little help! I loaded an ISO 100 black and white (traditional) film in my camera. Unfortunately, I didn't notice until now, at my 20+ shot, that my ISO was set at 400. I don't do my own developing, and I don't really understand or know darkroom stuff. Is there any way I can salvage the pics? What will I instruct the lab when I take the roll in for developing? Would the rest of the roll shot in the proper ISO setting be affected?

 

[clarence]

Shoot the rest of the roll at 400 as well and tell the shop to 'push 2 stops'. Everything will be fine.

Pushing 2 stops will develop the film as if it was shot at 400ISO (which it was). 2 stops, because 400 is 2 stops faster than 100 (the progression is geometric. 100, 200, 400).

Clarence

 

[jamiewakeham]

Kat,

Firstly - if there is a shot that you cannot miss in the bit that was exposed at ISO100, then develop the film at ISO100 and be damned to the first 20 shots.

Other than that - it would almost have been better to keep going at ISO400 till the end of the roll. What you would have done is effectively underexpose every shot by two stops. Then you could go to the lab and ask them to overdevelopthe roll by two stops (normally called 'pushing' by two stops). This would get all the negs out at the correct density, though perhaps with some loss of contrast or sharpness.

However, you now have some shots at 100 and some at 400. You could have the roll developed normally, and the shots at 400 would be too dark, or have it push-processed to 400, and then the shots at 100 would be too light. You're lucky in that traditional B&W is pretty tolerant to over- or under-exposure; I think I'd suggest developing at ISO400 and the shots at ISO100 will probably be fine.

Or you could split the difference, and develop at ISO200 (ie pushing by one stop). What do others think?

Jamie

edit - oops, stepping on Clarence's toes there! Kat - have you exposed any of the film at ISO100? If not, do just as Clarence says.

 

[jonasv]

If the rest of the roll has not been shot yet, shoot it at 400 as well and tell the lab to push process two stops. It the rest has been shot at 100, it's probably safer to tell them to push process two stops anyway: in my experience b&w film will handle 2 stops of overexposure better than one stop of underexposure.

 

[Kat]

Ah! I haven't shot anything at 100 yet, so I'll just proceed with my "mistake" and have the lab do as you guys suggested. Thank you, you folks are lifesavers.🙂 Whew!

 

[Finder]

I would stop shooting on the roll and develop it as suggested. I would not finish it as pushing a roll of ISO 100 two stops is not going to give you the best results - you have underexposed it so you will lose detail in the shadows and push processing simply compensates by overdevelopment which increases contrast. Just put in a new roll and start fresh.

P.S. Don't do it again. 🙂

 

[clarence]

It's traditional black and white so I don't think it will be too contrasty. I often preload several cameras with HP5+ and select the ISO on the fly. When I'm done with the roll I just mark the roll with the ISO I shot it with. I've developed it at 3200 before. It's high contrast, certainly, but the effect wasn't unpleasant.

Clarence

 

[Finder]

Clarence, you have an advantage over me as I don't know what Kat is going to be taking pictures of. I doubt a high contrast scene is going to be helped by the increased contrast of push processing. They certainly will not be as good as having normal exposure and processing. Since her next pictures may be very important to her, I think it would be better to change rolls and start new.

 

[Kat]

Thanks, guys. The roll and my next pics aren't that important to me (sort of just a test roll with el cheapo film), so I have nothing to lose by finishing it.

P.S. Don't do it again.

LOL, seeing the results should teach me that important lesson! I guess I'm lucky it happened with a test roll and black and white film to boot, considering that I use color most of the time.

 

[ZorkiKat]

The roll and my next pics aren't that important to me (sort of just a test roll with el cheapo film), so I have nothing to lose by finishing it.

Kat

If its "colpan" BW, forget about pushing it - it doesn't push well 😀

 

[je2a3]

Kat

If its "colpan" BW, forget about pushing it - it doesn't push well 😀

Hi Jay or Kat,

Do you know if Colpan is Lucky or Shantou?

I'm in town on vacation and picked up a couple of rolls of this stuff. Since there were no developing instructions in the box I shot a test roll with EI from 100-200. So far the film seems to behave similarly to Foma 100 when developed in Diafine @ EI 160.

Regards,

Joseph

 

[Kat]

Kat

If its "colpan" BW, forget about pushing it - it doesn't push well 😀

Sigh! Maybe I should just throw it out and start anew as earlier suggested, then. The price of the film is less than what I'd be spending for developing. Thanks for the warning. A little OT question, would you happen to have anything that can screw open the advance lever of a camera?😱 I've been trying for weeks to open the top plate of a Konica C35. The pair of "tweezers" I got from Quiapo got all bent and scratched the metal, but with no success.

Joseph, perhaps jay can answer you. I've never tried other B&W except colpan, so I don't really know. Though Colpan seems to be better than the pictures I've seen on the web from Lucky film.

 

[plummerl]

Over the weekend, I encountered a situation that needed at least 400 asa film. All I had was some Ilford FP4 and went ahead with using it at 400. Using Ilford's Microphen, the results astonished me. Check out the latest three shots in my gallery. Came through with great shadow detail. This was using it at stock (no dilution), 15.5m.