How much to push/pull

[kthompson]

Sorin, are you running this film yourself, or are you using a lab? This is important because, as was stated above, your light box intensity/color balance is going to have to match up with whatever your lab's viewing area is as well. So, yes, it probably would be best to ask for their advice as to how much to push. I work in an in-house studio and we run our own E6, so yeah it's possible to push/pull in tiny increments to either tweak your exposures, contrast, or maybe use it to "clean" up highlights. You can get by with pushing E6 better than pulling, although you can reduce contrast this way. It's just that as you do this, you also effect color balance, so it can get tricky if you're after correct color. Light tables for correct viewing (like in a pro lab) are rated for CRI (color rendering index) this is alot different than just any light box, so what may look good on yours, may look lousy at the lab. I have worked in studios in the past, that did this sort of shooting all the time, but we usually try to center all our exposures around what's normal for us, and use a std. 1st dev. time. You can really fine tune it though, like 15 sec. extra might be all you need. Maybe use the highlights as your guide first, because if you push too far, they're going to be the first to go. If you're running your own E6, I might be able to get together some times for you. I've found that it's just more predictable to learn to use polaroid and base your exposures off that (judging highlights). I just reread your original post. I think the answer to your hypothetical bldg. shot is "no" (short answer). Because trans. only hold like 5 stops, so you might want to shoot on an overcast day, or expose for the lighter wall, and use a massive amount of fill for the shaded one. If you pushed your film, you might end up blowing out your highlights. Maybe someone could suggest the merits of pre-exposure as well. Oh well, sorry for the length, good luck..

[heidis]

Sorin,

A good suggestion that has been made is that you need to learn (by your own experience and eyesight) what the differences in exposure will look like on E6. I'd like to suggest a way of learning this that will eliminate guesswork once you've learned what to look for. You can do this on a smaller format such as 35mm to save film costs. A longer series of test subjects will help you see the differences...

Try shooting a subject via your normal metering method. Let's say that you consider it mid-tone. Then bracket a half stop each way, and a full stop each way. You might even go further if you like. Then do the same thing with a light-toned subject, such as a snow-covered field, and bracket the same way. Finally, do the same with a darker than normal subject. You can expand this by covering a range of differently colored subjects too. It's not important whether your subject is a particular tone for this test, but you will easily be able to see the difference that various exposures make. For example, if your first exposure looks about a stop too dark compared to what you had in mind, you'll know to push the second exposure by a stop. Keep careful notes, and examine the results. Make sure that you can see each entire series at the same time, with the same illumination.

You should get a good idea of a half-stop from "ideal", a full stop from "ideal", and so on. This is basically the way that I learned how to spotmeter, and how to compensate accurately when metering a non- midtone subject. Good luck! Your English is very good, by the way

[Bruce M. Herman]

Sorin,

I frequently ask my lab to push or pull Velvia and Ektachrome (E100S, E100SW, and so far only a little E100VS). Here are some of the things that I would suggest.

1. Don't worry about calibrating your light table and theirs. However, you must be consistent in your use. So always use your light table (assuming that you have a decent model), and change its bulbs before they get to the end of their lifespan. I think that my Graphic Light bulbs are rated for 3500 hours, but your brand may be different. Also try to consistently view your transparenies in the center of your light table when considering exposure.

2. You must always use the same lab, and they must run a carefully calibrated processing system. If your lab doesn't serve professionals, you may not achieve satisfactory results. I say "may not" because even some amateurs have sufficiently good technique to do this well.

3. I have used a spot meter to give me a starting point for estimating the correction. But I usually make 3 transparenies in situations in which I am unsure of the exposure or too rushed to be careful (i.e., light is fading). At any rate, make your reading on something close to mid-tone color. Having said this, I think that you'll also discover that two different exposures of the same subject may both be acceptable. This is particularly true of sunsets. Experience will improve your results.

4. I have pushed all of the above films up to 2 stops and pulled them up to 1 stop when I really wanted to see the image. These are extreme situations, and they don't always work out well. But sometimes I get usable results.

3. Finally, don't throw away the slightly under- or over-exposed images. They can be scanned for printing after correction in a photo-editing package. Or you can use them as the basis for making 70 mm duplicates for clients, thus saving your best originals for those who really want a 4x5 transparency.

By the way, I learned this procedure from Pat O'Hara several years ago.

Best wishes, Bruce

[Sorin Varzaru]

Thank you for all the advice you've given. For the record, I am shooting 8x10 color slide so I kind of have to keep the testing down due to the cost involved. I also do my own processing. Since I've started 8x10 a few weeks ago I only shot 7 pictures (14 exposures) and so far all my exposures were exactly as expected (no need for any of the above). That is probably due to the fact that handling a camera of this size really makes you measure twice before you "cut" :- ). I'm still working on my focusing though. I've managed to get the focus plane in the most bizare positions :-).

[Ellis Vener]

I look at the extremes the highlights mostly to judge how much to push or pull. I know it isn't scientific but it works for me. If it looks like there is some grow there I might go a full stop on the push, or if I am very close to losing detail I want to retain, I stick to about a halp-stop push. Interestingly, it seems to me that an extra 1/3rd stop of exposure takes care of most of my needs to push film more than a half stop but it really depends on what the subject matter and the quality of the lighting is.

I made a very striking 4x5 image of Houston Mayor Lee Brown, a black man with very dark skin, that worked great on Velvia with a one-and-two-thirds push. The lower mid tones still had terrific depth and seperation while the mid tones "snap" and the white of his shirt is just below the "too much" threshold.

[Tony Novak-Clifford]

Sorin,

This is my preferred method for exposing color transparency when lighting remains consistent throughout the shoot. Until you gain some "intuitive" experience in evaluating and compensating exposure, I suggest you shoot at least 4 sheets of film, rather than 2...then you have extra sheets to test at compensated development times.

[kthompson]

Sorin, somehow I had a feeling that you were running your own E6. So, how are you doing it for 8x10, in a rotary proc. or what? (really just curious) If you're using Kodak chem. I may be able to give you some first dev. times for pushing/pulling. But, and this is only a suggestion, if you're just starting out with all this, you may find it easier to learn how to make a "normal" exposure and bracket with your exposures, rather than doing it in the dev. I only say this, because with all the variables involved with E6, it seems to me the simpler you could keep things, the better off you'd be. (i.e. using a std. first dev. time). Just a thought, that's all. Good luck.

[Sorin Varzaru]

DK, yes I am using a Jobo CPE-2 rotary processor. It's a bit of a pain since I can develop only one sheet at a time, but it's much faster then sending it to a lab and I have full control. Much cheaper too. I can use as little as 125ml of solution for 3 sheets. Although I usualy mix 150ml to be on the safe side. I do bracket when I'm using roll film (35mm and 120) but I came to realize bracketing (+/- hlaf a stop) and std development doesn't always work well. It happened quite a few times that I screwed up so bad while metering that the bracketed shots were bad too. Other times, I wish I had something in between the bracketed values. So, as soon as I figure out how to evaluate differences in exposure, I should be able to the the second sheet perfect. I use Tetenal 3 bath solutions. 6 + 1 STEPS is too much for me :-)

[kthompson]

Sounds like you have your hands full. Sometimes we even have problems with our Wing Lynch machine here as far as staying in control (as they say). We run control strips and all that good stuff to keep our color good (on a 6 bath set up), so...that's kinda why I was suggesting to keep everything simple at first. I was just thinking that if you kept all your E6 stuff consistent, you wouldn't have to worry so much about film density if you were in a trouble-shooting mode. E6 thrives on doing everything the same way, every time. I still might be able to get you some times for the Tetenal stuff, although I suspect Jobo has these on their website. So, what do you do? Reuse the chemistry you mix up and just adjust the times to each succesive run, or are you doing this one-shot all the way? Another suggestion, and this might not be practical, would be to try to get a reducing back for your camera, so maybe you could use Polaroid film to get an idea of what you're doing. You could also use 8x10 polaroid, but talk about expensive...

[kthompson]

Sorin, I've been thinking a bit more about your question, and since nobody else is jumping in here, I thought I'd ask you to clarify a couple of things. Are you reusing this chemistry after each run? If so, are you adding anymore time to your first dev. to compenstae for this? By some rough calculations (I'm not a Jobo-person...), I think you may be losing like a 1/4 stop each time you reuse the dev. I also am not sure about this, but you probably need to use at least 150ml per sheet (again, I have never used a Jobo, so I can't say for sure, I'm looking at a Jobo book right now..) you might actually need more than that, it seems like a small amt. to me, especially if it has any chance of oxidizing in use...What sorts of speed problems did you have with roll film? Have you been able to have some confidence in your development, or were things all over the place? I'm really trying to help you here, but you need to nail down your E6 before you start messing around with pushing/pulling. Maybe you could shoot two sheets exactly the same way, take one to a good lab and have them do it, and you run the other. Then, at least you could compare the results. You might not have a metering problem, as much as a developing problem. Anyways, just trying to help, I'm sure there are some Jobo people on this forum who can help you better than I. Good luck.