this question is related to what chaim just posted. . .
i just shot my first roll of IR this weekend. i read up on it first, thought i knew what i was doing, then i put on a 25 red filter, and set my camera to ISO 50. after reading the recent thread on IR, i apparently overexposed my film by three stops! should i try to pull it?

thanks!
jay

Which film were you shooting?

I'm assuming you were shooting Kodak HIE.

When you metered the scene, did you have the red filter on? If so, and your meter was set to 50, then you did overexpose. You're going to have some incredibly dense negatives. I do not have any personal experience about salvaging them in any way.

allan

yes, i was using kodak HIE. i realize it's a pretty bad situation. i was debating trying to do a clip test.

I wonder if low contrast and/or speed-decreasing developers & techniques work with IR film the same way as with other films. I would think so - it's still an issue of silver being exposed. If so, then you could various techniques to get something. Minimal agitation, low contrast developer, maybe something that loses speed so that you're getting back into the right ballpark, etc.

Anyone have ideas if that would work?

allan

I wonder if low contrast and/or speed-decreasing developers & techniques work with IR film the same way as with other films. I would think so - it's still an issue of silver being exposed. If so, then you could various techniques to get something. Minimal agitation, low contrast developer, maybe something that loses speed so that you're getting back into the right ballpark, etc.

Anyone have ideas if that would work?

allan

I'd give it a shot in PMK Pyro, and cut your developing time by about 30%. Base time is 12 mins at 1:2:100 dilution, so I'd give it more like 9 mins. That should get you into the general ballpark. The Pyro tends to require greater exposure in the first place, and it is really good for N+/N- development. The stain in the Pyro will also help control your (what will inevitably be extremely) blown-out highlights.

Another tip for working with IR - you'll get your best results with a #25 red if you set your in-camera meter to ASA 200, and let it meter through the filter. Try bracketing whole stops above and below to get a good feel for what look you like. With IR, a whole stop plus or minus not only affects the shadow and highlight density, but it makes a much bigger impact on the overall look/feel of an image. You may find you prefer the feel of images shot at ASA 400, or you may like the 100 stuff better, or the 200 may suit you just fine.

Jay,
I don't want to confuse you, but here is a website where the guy has examples of bracketing his shots, what he sees and his rationalization on using HIE.

http://mysite.wanadoo-members.co.uk/invisiblelight/index.html

The exposure info on that site jives nicely with what I've experienced. I find that even EI 800 with a red 25 is overexposed in sunny conditions with more than 75% vegetation. I have recently been using EI 1600 for those situations, 800 for more dappled situations, and 400 for overcast and interiors. I still bracket when I'm uncertain, of course.

It is nice to get more than 12 unique images on a roll...

Still not sure how I'd compensate for gross overexposure...I'm intrigued as to whether the aforementioned roll is salvageable.

allan

i developed the roll, and shockingly, it was salvaged!! thanks for all the input from everyone. i did two small clip tests so i didn't muck up the whole roll. i lowered my dilution, cut my development time by 35% and gave no agitation. the negatives are low in contrast (which i can compensate for in the printing), but i definitely have details in the highlights and shadows.

and thanks for the future advice on shooting ir -- i'm shooting it again this weekend, and i'm much better prepared about exposure this time.

Good to hear that you salvaged it.

Jay,
I don't want to confuse you, but here is a website where the guy has examples of bracketing his shots, what he sees and his rationalization on using HIE.

http://mysite.wanadoo-members.co.uk/invisiblelight/index.html

Excellent site Diane. Thanks for the link.

If you wish to pursue consistent exposures, or more important to find if there is in fact adequate IR to make the picture, there are methods to meter for IR.

For starters see: http://www.photo.net/learn/optics/edscott/pss00020.htm