11x14 infrared

[Craig Wactor]

A while back, I posted about experimenting with some Kodak medical infrared film I bought in an auction. The film is asa 1/20 - 1/100 depending on whether I use a 25a filter. This example was a ~45 min. exposure at f/32.5. I am also experimenting with semi-stand development. It looks good to me, but there is a patch in the upper left where the neg developed more. Any ideas what would cause that?
I am pretty sure it is chemical and not a light fog. I used a jobo paper tube. I did a 3 minute prewet with agitation. Then I filled it with Rodinal 1+200, agitated it for 30 seconds, let it stand upright for 1/2 hour, agitated for 30 seconds, then let sit for another 1/2 hour. I poured out the developer and used water for a stop bath. For that and the fixer, I put the tube on the rotary base.

http://glory.gc.maricopa.edu/~cwactor/Sunnyslope.jpg

[David A. Goldfarb]

Neat!

As far as that uneven spot goes, did you wash the film in a tray or print washer or in the drum? Sometimes when I've processed and washed film in a print drum, the anti-halation dye isn't washed out properly, so it looks like an uneven spot, and washing in a tray takes care of it. If the dark spot on the neg is colored and not just denser, you might try rewashing.

[Craig Wactor]

I washed it in a nova archival print washer for 20 minutes. I will give it a closer look to see if it is color or density...

[Scott Davis]

Given that this is Medical Infrared, this could be a hotspot caused by handling the film - that could have been where your fingers were in contact with it. Or it could just be a flow mark from where the chemicals first hit the film.

[Andrew O'Neill]

That is caused by uneven development. I had the same problem with HP5+ 8x10 and stand development in Pyrocat-HD. It is most noticeable in even tone areas such as sky. I solved the problem by pulling the film out and inverting it in the tube (BTZS tube) at my agitation interval. There isn't much difference (as far as sharpness goes) between a negative that received one agitation cycle during the hour stand time and one that received agitation twice (15sec each time). If you are going to be using stand developement, I strongly recommend you to expose a backup negative.

[Terence McDonagh]

Sort of off topic, but does anyone know where such film could be purchased new? I've scoured the web and found nothing amongst medical film suppliers.

I guess, in theory, any Kodak dealer could order it, right? Anyone have any idea of a price? 11x14 or 8x10 (or 7x11) IR cut down from 11x14 would be a dream. I haven't tried the Maco sheet film, but was not impressed with the 120.

[John_4185]

Pre-wetting is not necessary with stand development. In fact, I think it may be a bad idea.

Someone said Given that this is Medical Infrared, this could be a hotspot caused by handling the film - that could have been where your fingers were in contact with it.

Nope. Doesn't work that way. Not sensitive enough.

[Craig Wactor]

Yeah, this film is anything but sensitive. I really rate it at asa 1/100 with a red filter (that's asa 0.01). It does not tend to fog through the darkslide opening in the film holder (like the old kodak HIE sheet film did), unless there is direct sunlight right on the opening for a while.
I don't know where to get it new, all I know is that it is made for some type of fuji frontier like laser printer. The only info I found online was a very short tech info sheet on kodak's site. The film is 14x17, I cut it down to 11x14 in the dark.

[Terence McDonagh]

Thanks Craig. It definitely looks like fun. The shot you posted is great. Is the sky as light as it appears? I'm used to getting a nice dark sky with most IR film.

[Craig Wactor]

Yes, the sky is pretty light. I think it may be the filter I used. It is a gel filter that I inherited. It looked like a 25a, but may not be.
here is the tech sheet:
http://www.kodak.com/global/en/health/tiDocs/ti2425/ti2425.shtml
there are some tech sheets for similar films here, many have a spectral sensitivity chart with them that seems to be about the same for all of the films:
http://www.kodak.com/global/en/health/tiDocs/tiIndex.jhtml?pq-path=5380

I will contact the ebay seller I got mine from to see what he has left.