expose for shadows, develop for highlights

markbarendt said:

Okay I'm confused, a normal state BTW.

The reason I shoot 400 film is to be able to shoot at 400 (or more) not 250.

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The issue here is that the mfr says the film is 400, but if you look at the fine print, they also say that their published ISO is only a starting point and that you are responsible to determine the actual ISO that works for you. They aren't going to be responsible for your results, and want you to know it. You might sue them. In fact, the film you believe to be "400" may actually be "250" in the way you use it. Or it could be "400". Sometimes, but seldom, the rated ISO actually works. Generally, it isn't enough, in my experience.

Your "(or more)" is sort of interesting to me. Why would it not be a problem for you to increase the ISO but would be a problem to decrease it? The working ISO is hopefully not a guess and by gosh sort of thing. If you don't give enough exposure, you drop your shadows. That's the law. The notion of "pushing" film is a sort of a lottery, generally. If you want to get the maximum speed out of the film you are using, it is really important to understand the practical threshold and the response curve for your own materials. Without it, you are flying blind.

A lot of what we read gives the impression that we can just pick any old ISO (always higher, never lower) and just develop more to make it come out ok. If my livelihood were to depend upon the quality of my exposures, I'd be very careful about this.

I test. It can be boring, sometimes, but it saves LOTS of time, money, and disappointment.

bowzart said:

The issue here is that the mfr says the film is 400, but if you look at the fine print,

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Bowzart, I do understand that different processes and techniques can affect how a film reacts chemically and asthetically. I'm also not suggesting random developement. I'm suggesting that I get to set the rules for my shooting and developing.

bowzart said:

Your "(or more)" is sort of interesting to me. Why would it not be a problem for you to increase the ISO but would be a problem to decrease it? The working ISO is hopefully not a guess and by gosh sort of thing.

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This is just a matter of style and need, mine. I shoot mostly at 400 and some faster, almost never slower. Slower iso's just don't fit my style or subjects. If a specific film and developement process won't provide good results in the ISO range I need to shoot, it is an unacceptable film or process.

I'm also not suggesting that I fly blind by not testing. I just want to adjust different variables.

bowzart said:

If you don't give enough exposure, you drop your shadows. That's the law. The notion of "pushing" film is a sort of a lottery, generally. If you want to get the maximum speed out of the film you are using, it is really important to understand the practical threshold and the response curve for your own materials. Without it, you are flying blind.

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My question above is restated "why can't I simply adjust the way I shoot, i.e. open up more or less, to truly expose for the shadows at the ISO I want and use a standard unchanging developement process and expect good results?" This rather than changing both the rating and the developement I want.

Films aren't made for every ISO I might want so I have to bend the films to my will not vice versa.

Again, I'm not trying to get out of experimentation, it's just that shooting a at 320 or 250, normally doesn't work for me.

bowzart said:

A lot of what we read gives the impression that we can just pick any old ISO (always higher, never lower) and just develop more to make it come out ok. If my livelihood were to depend upon the quality of my exposures, I'd be very careful about this.

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For me, composition and subject rule the shot; my subjects move, sometimes quickly in dim light. To salvage some DOF and sharpness ISO has to give, not the subject.

CPorter said:

And, what do you think? Can you compare it to HP5 rated at box speed and developed normally with a similar scene?

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My objective was, having exposed HP5 at iso250, to find out how much I should adjust development time. 20% now seems a good starting point. Ideally I would try this shooting a roll of landscape, where the tones are less block like.

Years ago, I set my meter at 4 times box speed and read the deepest shadow where I wanted to see detail. Generally, the result would be the same as setting the meter at box speed and reading the average, or using an incident meter at box speed. In my scenes, which were onstage at orchestra dress rehearsals, the highlights prevailed and the average reading gave underexposure of the shadows. If I exposed so as to put the shadows near the toe of the curve, I could be sure of capturing the highlights by proper development.

markbarendt said:

....To salvage some DOF and sharpness ISO has to give, not the subject.

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If it works for you, what could I say?

My experience in dealing with this sort of thing has provided ample evidence for ME that ISO really doesn't give. What gives is invariably the quality of the result. If you rate at a higher ISO and then open up to compensate, it's the same as cutting the ISO.

gainer said:

...If I exposed so as to put the shadows near the toe of the curve, I could be sure of capturing the highlights by proper development.

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This is exactly how I would approach the situation you describe, in effect, though I might choose to deal with the ISO without modification and just count down stops. Often, though, we may not have the luxury of stable lighting. In dealing with projected spotlighting, where there is no ambient we can count on, it isn't possible to read the shadows in performance.

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We get pretty esoteric with this stuff, where I think the OP is wanting just to get at something that works reliably.

So, Steve, if you cut your ISO to 250 and take average readings, you will see that the shadows in your negatives will vary according to the brightness range of the particular scene. When there is a large brightness range, the shadows will be thinner. If you are working under flat lighting as in overcast, the shadows will have more density (edit: unless you are including the sky in the reading, which may cause you to underexpose since the sky, in overcast, is in fact the light source). Under the bright light, your setting the ISO at 250 will most likely prevent underexposure, but if the light is flat, you may be somewhat overexposed. I doubt that will matter very much, but it may bring the shadows up into the straight line portion of the curve, making them a bit more abrupt. Generally that doesn't look too bad and in many situations may actually enliven the image some.

I think that a good practical and intuitive test is what will be most useful for you right now. My suggestion would be simply to watch what the prints require. Your film development would be about right if you need to print the bright sunny scenes reliably on grades 1-2, and overcast lit scenes on 2-3. If you have to go higher than 3 very often, your development time is too short. If you find yourself regularly printing bright scenes below 1 (assuming vc filters, here) your development needs to be shortened.

I took most of my orchestra pictures from my chair as first oboist, and symphony orchestras seldom had to deal with dancing lights. My biggest problem was due to my own music stand, which made it impractical to use the auto exposure mode. Incidentally, I was taking these pictures with permission from the orchestra management and the Musician's Union. The musician's trusted me not to print unflattering pictures. The conductor liked being able to get pictures of the guest artists and himself, taken at dress rehearsal, the next day before the concert. The attachment shows conductor Russell Stanger discussing a point of interpretation with Ashkenazy.

Hey, that's great. Wonderful vantage point for a certain kind of shot. Ashkenazy certainly has come a long way since the Portland Oregon Youth Symphony in 1961, where I first heard of him.

Ah Mark,

You have a long way to go.

I suspect if you wish to shoot at those speeds, investigate the 1600 and 3200 speed films, shooting at 400-1000 E.I. Don't be shooting Tri-X or HP5 at 400 or 400+ and expect rated box speed. Unless you develop in Diafine or the like, you will be printing with no shadow detail.

I always shoot my Tri-X and HP5 at 200 and live with the slight increase in grain, but with full shadow detail.

Ya can't change the nature of the film.

tim in san jose

gainer said:

I took most of my orchestra pictures from my chair as first oboist.

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That's an excellent perspective which will give a viewpoint most other people will never see.

I posted in another thread that I had recently set up a friend with a manual camera and a few lenses as he wants to take some studio shots. He is a session drummer/percussionist and finds he often has spare time which he could spend taking pictures.

He is planning on using Delta 3200 and the f1.7 50mm lens so he doesn't need to use flash. I imagine that there will not be a lot of shadow detail in his shots. His first go at this will be Thursday and I expect I will be processing his film so I will find out then.


Steve.

Mark,

ISO and EI are different, even though they use the same numbering system. They are used to describe the same thing, but ISO is the physical speed of the film, while an EI is nothing more than an input into the exposure calculation, and can be tinkered with to get the results you want from your meter *without affecting the true ISO*. The only thing EI does is provide a variable that your meter needs in order to suggest an exposure for you. Your meter needs to know two things: amount of light measured (EV) and the sensitivity rating of the film (EI). For a given amount of light at an EI, your meter suggests the exposure (and equivalent exposures) that will render the metered area a middle grey; NOT the "correct" exposure, but a middle grey reference value. You can set EI wherever you need to set it in order to meter the way you want to meter. A film's sensitivity to light (ISO) is a physical feature of the film itself, which you cannot radically change no matter what EI you set your meter to. Think about it: How could setting an EI on your meter actually change the physical sensitivity of the emulsion itself? That's like putting lipstick on a pig and...well, nevermind....

The point is that your film is what it is out of the box, and you can't change that very much. The only thing selecting an EI does is provide input to your meter (or your head) for the purposes of exposure calculation AND/OR compensation for diffrences in materials and process variation between the film company and yourself. Not only are the variables numerous, but it is also largely a personal decision how you want to figure exposure. Some people want to use the EI that lets them place shadow tones where they want them, so they test for that. Some people want to meter a highlight. Others want to meter an entire scene. others want to make the exposure that will make all the tones fall into place more or less how they were at the scene of the picture (via incident metering). Changing an EI does nothing but instruct your meter so that you can get what you want out of it.

As for wanting your film to be a true ISO 400 film, you would have to do every single thing the same exact way Ilford did it, which is literally impossible. Not only this, but you would have to use the same criterion for calling the film a 400 film, which is not based on the threshold of density above film base plus fog density, but, rather, based on a measurement of the slope of the film's S-curve when it is developed to a predetermined contrast index. Blah blah blah, jargon jargon jargon. The point is basically that this is a rather inexact practice.

You are on the right track when thinking that manual exposure compensation (changing shutter speed or aperture from the suggested meter reading) will have the same effect as changing the EI and exposing at the meter reading. However, this does nothing to address the endless variables that will make your results different from the film companies'. The only difference is that changing the EI gives a more concrete and accurate meter reading, as it is designed to automatically compensate the meter across the board.

Just always remember the most basic fact: Your film's actual sensitivity to light is set when the film is made, and nothing you do can change that. Anything you do to EI is only helping you to be able to achieve controllable results.

ISO is not defined the same way as ASA was. They will both be about the same when the film is developed to a CI of .6, but development above or below that CI does change the ISO, which uses density = .1 above base + fog as the speed indicator. The film still has come contrast at that point. When that contrast is raised by increased development, the .1 density point is at a lower exposure. You cannot, however, get increased ISO without increased CI unless stand development really does work or you use pre- or postflashing or a chemical equivalent.

Tim and 2F/2F and gainer,

Thanks for the responses.

First my normal film right now is Delta 400, I do want to try some HP5 but that's not in the picture yet. Using Delta 3200 is an option but I'll have a problem there too, I probably won't be shooting at it's natural 1000 ISO much, I'd be pulling or pushing one way or the other. Delta 400 is at least naturally 400 ISO per Ilford.

Okay, so let me reframe this to see if I can learn where my thought process is off.

I don't want to reinvent the wheel. I don't want to give up the speed. I do want good quality. I do want the flexibility of being able to pull or push some reliably.

While I'm learning I want to process as close to "standard" specs for a film as possible, lets say for arguments sake I use ID-11 for delta 400, that means 8 minutes for a rating of 400. (I'm willing to practice and get the process down right.)

The spec sheet says DD-X should yield normal contrast here, assuming I do things right. I think what's left out of that sentance is that that is true only for a scene with normal contrast.

The two wild cards seem to be #1-how well I judge exposure, to get enough light in, to get the shadow detail I want at my chosen rating and #2-How well I adjust the developement time to adjust contrast.

If I learn to expose enough to get the shadows right at a any rating, 400 in this case, #1 should no longer be a wild card.

I should be able to get good shadow detail almost every time if I expose for the shadows, regardless of the rating, right?

Wild card #2 is harder, I need to judge the range of exposure in the scene and adjust the developement time to get the contrast right i.e. keep the developement time just short enough to keep from blowing out the highlights I want detail in.

Am I on track here?

What have I missed?

Defining #2 seems to be where the most work is.

The problem still is this: exposing ISO 400 film according to an incident light reading gives pretty much the same f-stop-time combination as reading the "significant" shadow with a spot meter set at 1600. If you tend to read brighter than average spots, you will reduce the film speed to get the same reading as the incident meter. IMO, the safest way to get a usable negative is to read the shadow spot with the meter set for the hifher ISO. Any film you can get will probably have very much more room at the top than your scene can provide. If you are using sheet film or shooting a whole roll of the same type of scene, as I was doing during my days in the Norfolk Symphony, you can be sure of a certain amount of shadow detail in the negative and worry about the high end in the printing. That is a description of the rule "expose for the shadow, develop for the highlight.

The camera does not see the scene as does the eye. As the eye scans a scene, which it must do because it's field of clear vision at any fixation point is about 1 minute of arc, it adjusts its sensitivity. You cannot see clearly both dots of this colon : at normal reading distance. Ask yourself if there is any difference between the dots, and you will find yourself scanning from one to the other to get the most information about the problem at hand. These differences between eye and camera must be taken into account in converting what the eye sees directly into a convincing photo. Sometime we don't WANT a viewer's eye to see the print as it would see the scene, and other time we want to emphasize something in the scene that a casual viewer might miss.

I keep getting older for some reason.

Great advice, as usual from the members of APUG. If you've the inclination, a film test done via The View Camera Store ( google for the link ) is very easy to do, and not expensive ( even after today' market decline! ). Feel free to contact me privately for additional details.

Ed

gainer said:

The problem still is this: exposing ISO 400 film according to an incident light reading gives pretty much the same f-stop-time combination as reading the "significant" shadow with a spot meter set at 1600. If you tend to read brighter than average spots, you will reduce the film speed to get the same reading as the incident meter. IMO, the safest way to get a usable negative is to read the shadow spot with the meter set for the hifher ISO.

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I have a little bit of difficulty with this, in that you seem to be assuming that all scenes are the same in their brightness range. I have to imagine myself here in the San Juan Islands on Groundhog Day, with heavy overcast, reading the "shadows" (just try to find one, like Puxatony Phil) with my spot meter set at 1600. I'd be overexposing by probably close to but just shy of two stops. Out on the desert in the Okanagan, 200 miles east, in bright sunlight, I might be right on. And you are right, as long as that shadow is placed appropriately, most films would handle the long range of light.

In general, though, I like the approach, though it seems to me that it may be a bit confusing to someone who's not quite so facile with grinding numbers in the head. I can do it, you can Certainly do it, but don't you think it would be simpler to just follow the example of, well, say, St. Ansel? I remember what it was like to be a beginner -- in 1963. It was confusing. It was really confusing. Did I say "really confusing"? I finally made sense of it, by reading the original AA series.

Mark, I understand that I probably pissed you off, but I'm just going to foolishly go ahead and get deeper in trouble. You insist in "pushing" and/or "pulling" when I really think that it would be far simpler for you and more productive of success to accept that film has a (as you say) "natural" speed, understanding that the "natural" speed may differ from the box's claim, and instead of changing the speed, work with it. Expose more or less as your interpretation of the light meter suggests from a stable ISO value, and as Mr. Gainer correctly suggests allow your film to hold your high values for you. Adding that additional "wild card" of variable speed really is more likely to confuse you than help you produce successful images.

Have you ever taken a science lab course? Pare those variables to the minimum! Change one thing at a time and then you know what is happening, that the result you see came from the one change you made, rather than from this one, that one, or an uncertain combination of both.

I know that I can be very direct, and that people often take it personally, though that is the very last thing I'd want. If I've been a bit rough, I'm very sorry. I can do that. Actually, I'm not universally hated. I don't think, anyway.

L.

I keep getting older for some reason.

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It's an illusion, Patrick. Immortals generally crave being like everyone else, and often have bizarre fantasies to make it seem so. That's all it is. Just denial.

gainer said:

The camera does not see the scene as does the eye.

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Good morning gainer,

This is true but I believe we can learn to see how the camera sees and how the film sees.

My first epiphany on this scale was being able to "see" (distinguish) the color of the light. I can actually do this fairly reliably now. This was huge in being able to filter reasonably.

Other epiphanies include things like seeing the context and composition and being able to move to the "right" place to shoot. Starting to "see" in B&W with it's requirements was another, not leaning on color as a crutch to carry a photo, that even made my color work better.

The challenge I see, with any specific film/process combo, is just learning how to expose reliably to put zones 2, 3, and 4 in the right place so that I get shadows I want. That will come with experience.

bowzart said:

Mark, I understand that I probably pissed you off, but I'm just going to foolishly go ahead and get deeper in trouble. You insist in "pushing" and/or "pulling" when I really think that it would be far simpler for you and more productive of success to accept that film has a (as you say) "natural" speed, understanding that the "natural" speed may differ from the box's claim, and instead of changing the speed, work with it. Expose more or less as your interpretation of the light meter suggests from a stable ISO value, and as Mr. Gainer correctly suggests allow your film to hold your high values for you. Adding that additional "wild card" of variable speed really is more likely to confuse you than help you produce successful images.

Have you ever taken a science lab course? Pare those variables to the minimum! Change one thing at a time and then you know what is happening, that the result you see came from the one change you made, rather than from this one, that one, or an uncertain combination of both.

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Hey Bozart,

No you haven't ticked me off, I have the same issue of being too direct at times. No offense taken, hopefully none given.

I guess part of what I'm trying to sort out is what's workable, not what's perfect.

My understanding is that for a given film the "natural" ISO will be different for differing developers, i.e. according to Ilford Delta 400 in Microphen or DD-X should be normal at 500 vs. Perceptol which should be normal at 250 or 320 depending on the mix and time. This is the normal I'm talking about.

If I need to use a specific process to make the film work where I like to shoot, so be it. If I need to use Delta 3200 at 640 or 6400 to get reasonable images in certain situations, so be it.

My first priority is simply controlling how the image gets in the box. DOF, Composition, propper shadow exposure. Shooting at an ISO that supports the artistic side of the shot trumps developement considerations for me, within limits.

If the right DOF, Composition, and propper shadow exposure can't be had in camera the shot's probably not worth working regardless of what the natural or normal ISO is.

That's not to say I will settle for junk. My second priority is good workable processes that support my style.

If I need to use Microphen to to be able to shoot Delta 400 rated at 500, I'm cool with that. If I need to develop Delta 3200 in Perceptol to be able to shoot at 800 nicely that's fine too.

What I don't want to do is sacrafice creative camera work.

markbarendt said:

Good morning gainer,

This is true but I believe we can learn to see how the camera sees and how the film sees.

My first epiphany on this scale was being able to "see" (distinguish) the color of the light. I can actually do this fairly reliably now. This was huge in being able to filter reasonably.

Other epiphanies include things like seeing the context and composition and being able to move to the "right" place to shoot. Starting to "see" in B&W with it's requirements was another, not leaning on color as a crutch to carry a photo, that even made my color work better.

The challenge I see, with any specific film/process combo, is just learning how to expose reliably to put zones 2, 3, and 4 in the right place so that I get shadows I want. That will come with experience.

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Yes, we learn to see as the camera. We learn that almost any scene with a window in it will fit on the film, but not on the paper without some dodging/burning. That is because that scene, to the eye, is really two or more scenes. If we try to compress all that information onto the film so that it prints without manipulation onto the paper, we have a very low Contrast Index, and the test print will tell us to use a higher grade of paper and dodge or burn. Dodging and/or burning is inevitable in these circumstances. The same situation arises in out west where the far distance is much closer to infinity than any I can get in my part of West Virginia. Even where I live, it is difficult to shoot valleys where the sunny side of one mountain and the shaded side of another are in the same scene. So, minimum exposure for the shaded side allows shadow detail there and the other side falls where it may on the negative, but will not be washed out with normal development, but dodging/burning is needed whether or not I try to get both "ends" of the scene onto the film in a density range that will fit the paper by underdeveloping the film. Painters know this fact, and "Fool the Eye" into thinking it is really looking out a window, or seeing a real sunset.

gainer said:

Yes, we learn to see as the camera. We learn that almost any scene with a window in it will fit on the film, but not on the paper without some dodging/burning.

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I fully agree gainer.

Printing is a "whole 'nother can-o-worms" beyond this thread that I need to learn!

There is another aspect to this.

One CAN learn to see as the camera. One CAN see in such a way that dodging and burning, while never eliminated altogether, can be reduced to a minimum.

bowzart said:

There is another aspect to this.

One CAN learn to see as the camera. One CAN see in such a way that dodging and burning, while never eliminated altogether, can be reduced to a minimum.

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A noble goal, in color I shoot slides pretty much for that reason. I want to do most of the work at the camera followed closely by a solid developememnt process.

When I get to the printing process I'd like to have very little work left.