What do you get when Developing Infrared Unexposed film

[RenA]

Hello all,

I have a question: what do you get if you develop unexposed infrared film? I have read that I can use this developed film as a infrared filter. But when I talked to a guy in one of the online shops, he wasn't 100% sure but said that I will get clear film. He recommended this forum to get definitive answer. I don't normally shoot film, but need IR filter, that will fit into a thin slot at the end of a fisheye lens. Standard poly filters are too thick for this job and I just can't find a foil that could be cut to size and serve as an IR filter.

Thank you very much in advance.

Ren

 

[holmburgers]

No, you're somewhat confusing two ideas.

What people do is use unexposed and developed slide film, E6, which as you can imagine would be totally "black". Any film developed as a negative is going to be clear if it's unexposed.

The silver in b&w film would probably impede IR energy too, making for a poor filter; dyes in general (and in E6 particularly) are notably "open ended" in their IR+ transmission, partly to curtail overheating in projection.

 

[Bill Burk]

Yes, a fully black E6 slide could be used as an infrared filter because infrared goes right through it.

But it would not be good to slide inside a fisheye lens because it would not give you very good image quality.

However you could use a slide over an electronic flash and discreetly shoot at night with it.

 

[RenA]

Thank you very much to both of you for such a great and fast answers.

 

[cliveh]

Yes, a fully black E6 slide could be used as an infrared filter because infrared goes right through it.

But it would not be good to slide inside a fisheye lens because it would not give you very good image quality.

However you could use a slide over an electronic flash and discreetly shoot at night with it.

Bill, I have never tried this, but it seems that it could have some interesting possibilities. I enjoyed seeing Weegee's infrared pictures taken with infrared flash, but is there enough infrared emitted by say a compact flash camera, with the flash covered by an non-exposed E6 slide to work in this way?

 

[Bill Burk]

I think an E6 over an electronic flash would be as effective as a Wratten 87 filter.

I just held a couple slides over the Vivitar 283, in the darkroom and looked at it through the ATN Viper IR monacle.

Get nice bright pops from the flash.

 

[eatkabab]

Would anyone here have any unexposed, developed slide film they could mail me? I'll gladly send you a couple stamps, maybe a little Bitcoin, or a PayPal dollar? I'm looking to retire my floppy disks for good.
Thanks very much!!

 

[Denverdad]

Would anyone here have any unexposed, developed slide film they could mail me? I'll gladly send you a couple stamps, maybe a little Bitcoin, or a PayPal dollar? I'm looking to retire my floppy disks for good.
Thanks very much!!

How large a piece of film did you need? Actually, I am not sure if I have any at the moment, but if per chance you were wanting to make a Series-VI size filter, I would be happy to send you one of the ones I made:


I can show a comparison between images made with the homemade E6 filter and an "official" IR filter too if anyone is interested.

 

[ntenny]

I didn't use slide film, but I did once make an infrared flash filter by combining cinema gels; looking at the transmission curves suggested that it should have been similar to a Wratten 87. It worked, as far as I could tell, but unfortunately Rollei's IR film is so slow at those wavelengths that it was pretty impractical. If we still had HIE I bet it would have worked a treat.

-NT

 

[winger]

Years ago, I got a filter sample pack from Roscolux. The samples are just an inch or so by 3 inches, but that's enough to cut a piece to fit in the back of a fisheye. I originally got the pack to make some orange filters for a microscopy thing at the lab (needed to filter close to a sodium D line to look at the refractive index of glass shards). I don't have the rest of the pack here to see which one I used for the fisheye, but there was one that worked (a dark red). My camera was still able to autofocus and meter through it and I know I have some decent HIE shots using the combo. I don't know if this is quite what you need or not, but it worked for me.