Konica 750 starting points

[Rich Ullsmith]

I came by several rolls of this stuff cheap-cheap at a darkroom sale (it had purportedly been frozen since purchase, and I believe it to be true). Going to the massive chart, there are no recommendations on processing, and searched this forum for starters but could not find what I was looking for.

It appears that f5.6@1/60th s with a red 25 (in bright sun) is recommended for exposure. Would an 89b produce more IR effect with this film?

As for developers, I have PMK, Rodinal, Perceptol, D76, and I think some Microphen. I'd like to stick with the first two. Any suggestions on processing times for this film? It's 120 format, if that matters.

Of course, the film could very well be toast. But worth a try! Thanks up front for any and all suggestions.

 

[Ian David]

Hi Rich
Nice film. I still have a handful of rolls myself in the back of my fridge. There is some info on Konica 750 in the "Unlisted data" part of the Massive Dev Chart. This link will hopefully get you there:

http://www.digitaltruth.com/devchart.php?Film=IR+750&Developer=&mdc=Search

 

[Rich Ullsmith]

That's it right there! Maybe shoot 12 frames, alternate the 25 red with the 89b, cut it in half in the dark. That should get me pretty close pretty quick. I think I have 8 rolls, and I didn't want to blow half of them figuring things out. Thanks again.

 

[Ian David]

Hi Rich
Glad that link helped. I am not an expert on the Konica film, but I don't think you want to go too heavy with your filters because the film is not very IR sensitive. So if you cut out too much of the visible spectrum, you may not get great results. Then again, no harm in trying half a roll!
I have used a red 25 with good results though. Perhaps try a red 29?
Ian

 

[Philippe Grunchec]

I find red 29 perfect with Konica 750.

 

[Jeff Kubach]

I used Konica 750 a few years ago and followed the instuctions. I got excellant results!

Jeff

 

[Anscojohn]

I used Konica 750 a few years ago and followed the instuctions. I got excellant results!

Jeff

*******
FOLLOWED THE INSTRUCTIONS!? What kind of Apuger are you???

 

[Jeff Kubach]

I geuss not a very good APUGer!

Jeff

 

[wildbill]

I always use it with an 89b. 1/8@16 is my usual exposure when it's sunny, maybe 1/4 earlier or later in the day, this works when processed in tmax or pmk. I think I shot some with my red 29 at some point but the results weren't as favorable to me.

 

[glbeas]

Best results I've had were with Technidol with an EI of 12-25 with an IR filter, I think it was an R72. I've used Rodinal at 1:75 with okay results. You mostly have to underdevelop a bit to keep the highlights under control, the Rodinal I needed an EI of 6-9 to get good results.

 

[steven_e007]

I've had good results with a Wratten 29 in the past. It's a deep ruby red, but definately not opaque like the 89b. It looks very similar to Ilfords SFX filter. I found the 89b chops the useable film speed right down.

As it happens we have very hot weather in the UK at the moment (well, hot for us!), very sunny So I shot a roll last week, one of my last four.

Thing is, I just happen to have Ilford Perceptol mixed and ready to go, which I've never tried before. Last batch I developed (a couple of years ago) was in Acutol, alas now defunct. Anyone developed Konica in Percetol 1+3? Any ideas?
Alas, it isn't in the massive development chart...

 

[Rich Ullsmith]

I'm just waiting for the sun to shine here in the PNW. I have a red 29 also, but would have to hand-hold it over the lens . . .guess there's no law against that. Hey Wilbill, what time/temp/agitation do you use with the PMK?

 

[Doug Webb]

I exposed Konica IR mostly from EI 3 to EI 8, maybe most often at EI of 6, depending mostly on how bright the sun was, degree of cloud cover, and height of sun in sky and used mostly an 89b filter (other red filters don't give as much infrared effect, which I was after, meaning for example white foliage). Wish I had some Konica IR now to shoot. If I had some now I would develop it in PMK 1:2:100 at 70 degrees from somewhere around 6-7 minutes for EI 3 to around 9 minutes for EI of 6 to around 10-12 minutes for EI of 8. If by PNW your mean Pacific North West you may be shooting most often at EI 6 or below, it never seems to get as bright there as in say, Florida. No way to know how the film may have been impacted by storage, so I would shoot an exposure of a single scene at about 3 different EI's, then just repeat the same sequence 3 or more times, then cut the roll into 3 or more strips and develop for different times that way you are likely to get one good frame that could be a keeper on your first roll. The film being old could be less sensitive. With PMK I agitate according to the Book of Pyro instructions. I think I have some images made with Konica IR in my gallery that will give you some idea of my results with this film.
Good luck
Doug Webb

 

[Rich Ullsmith]

That's sort of what I was planning on doing first role, but throw in the 89b filter for a few just to see. And break with tradition and keep notes on it.

It was a helluva garage-darkroom sale. Three rolls of HIE, 100 sheets of Tmax 100, untold rolls of Tri-X, maybe eight of the Konica, and a duplex safelight. 40 bones, no kidding. Unopened 16X20 MCC111 and 11X14 Ektalure G, too. I got the goodies, but now I need the time!

 

[MultiFormat Shooter]

I find red 29 perfect with Konica 750.

I know this is an old thread, but I'm interested in trying Konica IR 750. What EI do you use with this film, with the 29 red filter?

 

[Andrew O'Neill]

I used the 120 extensively back in the 90's in Japan. I used #29, and a 89b. EI 3 and EI 1 respectively. Xtol 1+1.

 

[MultiFormat Shooter]

I used the 120 extensively back in the 90's in Japan. I used #29, and a 89b. EI 3 and EI 1 respectively. Xtol 1+1.

Thanks! Is a red 25 about the same as the red 29, in terms of EI? I have both filters.

 

[AnselMortensen]

29 is a deeper red than 25...with IR, it drops the EI

 

[Patrick Robert James]

I haven't shot Konica IR for about twenty years at least, but I still remember the exposure for bright sun with a red 25 was f/5.6, 1/60. You'll probably need more that that though because any film around these days will be less sensitive by a stop or so.

 

[Andrew O'Neill]

Bracketing will be in order. I shoot a lot of IR film, but not this time of year, up here. Have fun and share your results with us, please!

 

[MultiFormat Shooter]

@Andrew O'Neill and @Patrick Robert James, thanks for the information/tips! If I get any decent shots, I'll post them. It may be in the spring, though.