Re: Push 400 to 800 in HC110
In general, a one-stop push requires a 50% increase in development time. You're going to have to run tests, and there's a starting point. That was the standard practice when I processed b/w film in the custom labs where I worked, long ago.
I'll be interested to hear how real users do this. I can see where it would come in handy with my own 3x4 Speed and the HP5+ that I use with it.
Re: Push 400 to 800 in HC110
If you are happy with your 320 negatives in HC11B try the same time but use a dilution of 1.25 to 30.75 instead of 1:31. You really need to run your own tests. I have posted on this subject before. Here is a link.
https://www.largeformatphotography.i...85#post1523985
Re: Push 400 to 800 in HC110
I've pushed HP5+ to 1600 and developed in HC110. It was 120 film though. Not sure how much of a difference that makes. I was very happy with the results following the massive dev chart. 1+31@ 11 minutes
Re: Push 400 to 800 in HC110
You're not really pushing anything, but just lopping off at least one zone of shadow values, and expanding the density of what's left by increased development. I like TMY400 for this. You might get bold black in the deep shadows, but that can be used for graphic effect; and I personally like it a lot better than just a sliding scale of mush down there. And because this film has a longer straight line, further down into the shadows than the other options, you still get more consistent gradation even at underexposure.
But it is very important to carefully meter shadow values for TMY; it's not a wise film for exposure guesstimation. I'm trying to remember my times for HC-110. With PMK pyro, which is normally true box speed of 400 @ 20C @ 14min, I would use around 16 min dev for exposure at 800 (NOT 50% more time). If it were 1:3 Perceptol, which is ordinarily 16 min, I'd try 18-20 min for 800 ASA (note that is 1:3, not 1:1). Maybe someone can equate that to HC-110 B times. I use HC-110 in the lab much more dilute for specialized applications, so don't have the times on hand you specifically need. But HC-110 B would be approximately half the time of Perceptol 1:3, so I'd inititally try 8 min with that
for ASA 800. But any recommendation like this has to be tested and fine-tuned to fit your specific personal method of development.
Re: Push 400 to 800 in HC110
Keep in mind that Kodak does not recommend pushing development for either TXP or TMY if you're exposing at 800. The respective data sheets recommend pushes only for EI 1600 and beyond. Their language in the TMY data sheet is as follows:
The nominal speed of KODAK PROFESSIONAL T-MAX 400 Film is EI 400. It was determined in a manner published in ISO standards. Because of its great latitude, you can underexpose this film by one stop (at EI 800) and still obtain high quality with normal development in most developers. There will be no change in the grain in the final print, but there will be a slight loss of shadow detail and a reduction in printing contrast of about one-half paper grade.
When you need very high speed, you can expose T-MAX 400 Film at EI 1600 and increase the development time. With the longer development time, there will be an increase in contrast and graininess with additional loss of shadow detail, but negatives will still produce good prints. You can even expose this film at EI 3200 with a longer development time. Underexposing by three stops and using three-stop push-processing produces a further increase in contrast and graininess, and additional loss of shadow detail, but the results will be acceptable for some applications.
https://imaging.kodakalaris.com/site...3_TMax_400.pdf
Re: Push 400 to 800 in HC110
You lose one effective Zone of shadow value by a one stop underexposure because the straight line of TMY is so long, and any resultant gamma (contrast) loss can be easily made up by MILD overdevelopment (approx 15%, depending). I don't even like using the terms "push" or "plus" in this case, but have done what I just described many times with totally predictable results. "Pushing" is really a commercial lab term originally associated with tweaking automated processor commands etc for minor changes in result, or related exposure correction. It analogously applies when similar machinery is used to process black-and-white film, but has now somehow invaded general terminology, especially among the younger generation. No need to get into a nitpicky argument over specific machines or lab price lists. But in principle, I think its simpler just to recommend what be specifically done rather than trying to force something into a less than ideal pigeonhole of terminology. It's just a matter of whether you want to cut the toes off the man, or the legs clear up to the kneecaps, cause that's the gist of underexposure.
Re: Push 400 to 800 in HC110
This is all great information. Thanks to everyone for their thoughts. Drew and Oren, thanks for recommending TMY as a recommended alternative for exposure at EIs above box speed; and Neal, thanks for pointing to a change in developer concentration as another approach. So many wise heads here. Much appreciated.
