Grey scale . . . color chart ?

[Bonner]

I agree with all you say but take exception to the last statement. If you meter the white background only, and shoot it at that setting, you will have an 18% grey exposure. -Jim

[Doug_Lester]

"A camera has a useable range of tones it can capture. Depending upon whether you are using film, digital, or chromes, the latitude varies, but any tone within that latitude is useable and is neither overexposed or underexposed."

Yes, sort of, well actually the media, film or whatever, not the camera itself and there is no sudden point at which over/under exposure happens, it a gradual curve.

"You can use a light meter and theoretically, it gives you a base exposure, ie the theoretical proper exposure for capturing the widest ranges of tones in an image."

Yes, I agree.

"So lets say I meter my lights at f8 and plop a model down in front of my camera. Theoretically, if I set my camera to F8 and the meter says f8, I have set the "optimum" exposure."
Yes

"But f8 isn't the only tone that camera will record. It will record highlights up to the point of overexposure, and it will record shadow detail down to the point of underexposure."

Yes

"The "range" between a highlight burning out and a shadow going completely black is your "latitude"."

Agreed

"My argument with "meter freaks" is they act like (some not all) that you then don't take your subject into account at all."

There's little need to with an incident meter reading

If I want to, I can have the lights set at f8, and assuming I have three stops of latitude, I can set the camera at f5.6. This will have an effect on the subject. The subject will be "brighter" than if I shot her at f8. However, it will still be within the latitude of the camera to capture. So long as I don't burn out any highlights, there is nothing "wrong" with shooting the photo at f5.6.

Yes, but your overall exposure will be off and 'off' exposure has a detrimental effect on and image, depending on the media used to capture it. For example Tri-X film has an exposure latitude of 5 or 6 f-stops, whereas transparency film is much, much less, as litle as a half stop. Digital is much more like shooting chromes thqn negative film. The problem is that highlights 'will' blow out, or will art least approach that point.

"If I want, I can stop down to f11 (leaving the lights at f8) The subject will now be darker than when shot at f8. So long as I don't block up my shadows, I am within latitude of the camera to capture the image."

Yes, you'll capture an image, but low tones (shadows) will begin to block up.

"You might say "well, why would you want to do that". Well, because, in most cases, I am not just metering a single light on a single subject at a single spot."

Granted.

"I might want a highlight at 5.6 on the left side of the face, middle tones acroos the center of the subject, and dark shadows on the right. If the camera has 3 stops of lattitude, all three areas will capture, and yet only one of the three areas will meter at f8.

OK, but again, it isn;t the camera and latitude will vary tremendously depending on what you are shooting on.

"I have neither overexposed/underexposed any part of the image."

You are right, sort of

"I might want to shoot a dramatic shot with a grid on a light and put the light right on the models face. I might meter at f8 but set the camera to 5.6 so that the face is "very bright" in relation to all the other tones in the image and I might want my shadows and fall off to be very dark."

Here is wher we disagree, the nub of the question. What you have with your technique is an incorrectly exposed image, which may still work. When I taught photogrpahy for 'Uncle Sam', at the beginning of the first ghour of the forst day, I wrote at the top of the blackboard in large letters, "Get it on the negative!". If it was not on the negative, it didn't exist. I believe in absolutly accurate exposure, which will reord all of the information on the film. Then in the darkroom (post procesing) I can lighten and darken in any way I would like. I can choose different paper develpopers and paper grades for different effects, I can under or over develop the print to compress or extend that 'latitude', but I have the correct info in the negative. The 'correct' negative gives me options you might not have with even a slightly 'incorrect' exposure.

"In a studio, where you can control the light, any light from any direction that is within latitude, is neither overexposed or underexposed, if it is within the capture latitude of my device."

I disagree with the "any light" part. Not all light is wanted, ie blowback from the background in a high key shot, spill of a hairlight onto the mdoel's face etc can easily caure exposure error.

"I can control the lights to any degree I want so long as I stay within the latitude of the capture device."

Agreed

"Outside, in many cases, the available light is many stops outside the latitude of my capture device. I can therefore place my subject in a shadow, and sacrifice the highlights in the background for the amount of light I want on the subject. Metering gets you close, and then from there you have the right and ability to control highlights, shadows and the subject within the latitude. The subject then effects my choices. If I shoot a grey mouse on a grey blanket under flat lit conditions, I may be able to shoot the shot with several different f stops as I will still be within the range and latitude and am neither sacraficing higlights or shadows because the light falling on the subject is a very narrow latitude."

Sure you can, but the further you move from the optimum exposure, the more problems which can arise.

"On the other hand, if I put a black shirt and a white sweater on a model who is fair skinned, I may find that I have to make the choice of sacraficing the detail in the black shirt to get the light I want on the model's skin where I want it. I might end up sacraficing the highligts on the white sweater for detail in the black shirt."

There is where I believe you are making an error. Instead of sacrificing detail, why not add controlled light to the darker areas. That's what snoots, barndoors, etc are for. By adding light from a snoot or grid to the black sweater, you bring the extremes closer together so that nothing has to be sacrificed. A typical case would be a model wearing a light shirt and a black skirt or pants. By adding controled light from the side for example, the white and black tones are brought closer together, so that detail is not lost and you gain thebpnus of revealing the texture of the black fabric. Had the base exposure been changed, then detail in either the white blouse fo black pants/skirt would be lost. "Get it on the negative!"

"I understand and I am not arguing the point that the meter gives you the base theoretical exposure that may be "optimum" but YOU have control over tones in an image as long as they are within the latitude of the film and and you control the light to avoid highlight burnout and blocking up the shadow areas."

Certainly there can be occasions in which we might take readings from two areas and average them, no question about that. But when possible, adding or subtracting light is much prferable.

There are two styles of black and white figure photography that are posted here on a regular basis. One is dark, moody and somber and the other is the more blown out style."

I plead guilty to that!

"In fact, it is a well known fact that you can "overexpose" black and white....which is actually a misnomer....you are recording light within the latitude of the film, but above middle grey, for the effect it has on the subjects skin tones. When you do this, you are exposing the film above the meter reading, but within the latitude of the film. It's a choice you have available."

Yes, but because it is "well known", does that make it either correct or the bet way? Again why deal with incorrect or modified exposure when it's so easy to get it right by controlling the light? I think you ( and many others) might have a misconception about the 18% grey thing. The idea of getting exoposure correct for 18% grey meand that if that tone is accurately exposed, then all of the tones will be accurately exposed.

"Being a slave to one and only one meter reading is what I object to. Perhaps we are saying the same thing."

Is it being a slave to a meter or is it using it to its maximum? I really dont think we are saying the same thing, I believe we have different basic concepts.

"I might agree that metering the lights at F8 gives you the theorectical reading to provide the greatest and most accurate range of tones in an image. But I might want to skew the balance (but within the latitude) by either opening the aperature or closing it down....in which case I am not shooting what the meter tells me."

I believe that any time that's done with an incident reading, it's an error.

"In very low light (available light conditions) where the light is very flat, I can set the the camera one to two stops away from the meter reading and get better shots than using the meter setting."

I really disagree. In the past I did a grat deal of shooting in conditions so dark I had to use a flashlight to focus and see the settings. I would take an incident reading, lock it in and move to a lit area to read it. This was obviously sturdy tripod and cable release country with exposure in minutes instead of seconds, but the esposure was always on the money, as metered. Two steps away from the metered exposure would have caused serious problems. Other dark situations required 'extreme' push processing, intentional underexposure but balanced with over procesing, and the metered exposure was always on the money. Sure, you can often get by with a 2 stop error, but why settle for unnecessarily degraded images when it isn;l tnecessary?

"I understand the difference between using a reflected reading and an ambient reading, but once you have your ambient reading, you can still "deviate" as the case may be.
Theorectically, if you meter at f8 on a white background, you background should be white, but we all pump more light on the background. Why do we do that?"

Uhhh, actually I don't. When shooting high key, I meter the model, then light and meter the background for one stop more exposure as I want little or no detail there, or sometimes for the same exposure.

I'm not saying your way won't work, just that mine will work a little better. The attached was shot precisely as metered with an incident meter aimed at the one light, which was equipped with snoot.

[Doug_Lester]

Actully no, unless you meter it with a reflective meter. With an incident meter white will go white at the metered exposure. A reflective meter 'thinks' it is always reading for medium grey, whereas the incident 'is' always metering for 18%. In the attached shot, the lights were bounced from the ceiling to flood the area with even light. My incident meter read f8 over the entire area, including the background and that's how I shot it.
My place

[RonC]

Hi Doug,..question,..where do you aim the incident meter, camera, key light?
I would think at the camera, and let the meters dome "average"(is that the right word?) the light stiking it. I'm asking because I'm new to all this, and there was a discussion about this on another forum awhile ago.

Thanks in advance, RonC

[Gunfitr]

Doug:

First of all, thank you for an intelligent reply.

Here's part of what I am saying.

Let's say you place a model on a black backdrop.

You have a light to the right metered at F8.

You have a light to the left metered at f5.6.

Which light and meter reading are you saying is your "theoretical" perfect exposure?

It can't be both.

You might say, well, "I'm calling the F8 light my "main" light and thus my 5.6 light is my fill"

You could also say that the 5.6 is your main, and the f8 is a "rim" light set 1 stop over.

So now introduce a hair light at say a half stop over f8.

We now have 3 different meter readings.

If you consider the hairlight as pushing the top end of your latitude, then you have a fill set quite near the bottom of your latitude.

The "skin" being lit by the f8 light is going to look "brighter" than the skin lit by only the f5.6 fill. But neither level of "brigtness" is "incorrect" nor is any one meter reading "perfect". But by adusting your lights, you are changing the relative lightness of certain parts of the subject by the combination of aperature and light levels. If you chimp the screen or shoot a polaroid, and determine that you want more light on a particular part of the image, you add it or can open up and re-adjust the other lights. Now you are deviating from your original meter reading to get the result you want. It's not like one meter reading gives you the perfect exposure to skin. There is no perfect skin exposure. It's what you want it to be within latitude.

So now take some baby oil and make your model all "shiny".

Take a new photo, and you are going to see a "change" in the image. You may even get some very bright spectral highlights off the baby oil. Thus my claim that the "reflectance" of the subject effects your image.

There was talk on here a couple weeks ago about metering for african american skin. Say I set a main light at f8 and a fill at 5.6. If I decide I want more light on the model, I can open my aperature and thus shift things a bit.

Mind you, I have said, that in such a case, you have to avoid blow out.

But assuming you get no blow out, you are simply shifting tones within the latitude. Neither tone is "wrong".

You could just as easily shift the tone within latitude, by applying more light rather than opening up a half stop.

Assuming I have the model pulled off the black background, black is black, and so long as no light is reaching the black background, opening my aperature a half stop will not change the background color. What opening up half a stop will do is "brighten" the tones where the light is falling.

So long as I don't open up to such a degree that I push highlights off the high end of the latitude, I don't see how you can claim there is one "perfect" exposure.

I guess you could consider the meter giving you a "median" for purposes of latitude. Once you have your median, a certain amount above and below that is going to break your end points.

If I have three lights set up at various ratios, and I want the entire image to be brighter in all regions, I can either turn up all three lights or I can open up my aperature. Can't I?

In such a case, I am thus deviating from whatever my base meter reading was whether I do it by turning up the lights or opening the aperature.

If I had a black tone in my image hanging a 5 and a white tone in my image hanging at 250, then yes, opening the aperature would skew my shadow and and highlights.

But if my hairlight is hanging at 210 and my black point is hanging at 35, whether I increase the light falling on my image by turning up the lights or opening the aperature, light is light and I can capture it by turning up the lights or opening my aperature.

Your objection might be that I want to keep my black point down around 30.....but what if I don't want to.

What if I have a piece of dark fabric on the model that has some weave detail that I am not capturing at a black level of 30, but it starts to show up at a black level of 40.

My two options are to turn up the light or open the aperature.

I'm smart enough to understand that if I shift my light on the black end, it will give a corresponding shift to the high end, but if the high end hasn't reached maximum recordable, there is no difference between adjusting the lights and adjusting the aperature. In either case, I will be recording more light than my original meter reading.

If I am shooting on a white backdrop, I can turn on a light and use no meter. I can fire a test shot and look at my historgram. If the spike is in the center, I can turn up the light or open the aperature to shift the white backdrop to a brighter shade of white. And some point, the white backdrop will go above 255 and blow out.

I can turn on a "main" and place my model in the foreground.

I can shoot a test shot and if I decide I want my model to be "brighter" I can open my aperature. This will have a corresponding effect of likewise blowing out my backdrop further. I may want both of these "effects". I can obtain both of those by either turning up the lights or simply opening my aperature.

I don't care what my meter says, I care about what my image looks like. You seem to be assuming that I don't care about light control. I do. I understand.

I understand about blow out, and I understand about blocking up my shadows. But if I shoot three shots and in one the skin of my model registers 210, and in one 220 and in one 230, the question is whether I like the tone at 220 versus 210 or 230. None of these relative levels of "brightness" are wrong and each would record at a different meter reading. You can't then say that one is metered correctly and 2 are metered incorrectly.

I'm talking about metering a specific tone in an image and I think you are talking about metering overall.

This all started because a guy asked about shooting a grey chart.

So let me ask you this. If I shoot a grey card as my "subject" and I measure it out to be 127 in photoshop, but I want it to be 160. I can either turn up my lights or open my aperature right? Let's assume that this grey card and the color it represents is THE tone I am most interested in in the photo. I don't care what the meter says, I want that tone to be 160. If a meter reading makes it 127, I am not getting what I want. So I adjust my lights or my aperature to pin that color at 160. From there, I set up other lights in my shot wherever I want them and taking into consideration my latitude limits.

In a theoretical world, I am overexposing a grey color to force it to 160. I can force the rest of the image (both highlights and shadows) to come into line with how I want my target grey to be. But nevertheless, I am not "accurately" reproducing my color because I have forced what should record as 127 to 160.

This is no different in my mind than cross processing film.

Sure, it's going to do wacky things....maybe I want wacky.

And image doesn't have to contain pure black and pure white in all instances does it?

If all my tones are middle tones, what's the difference between opening my aperature to increase the relative appearance of all the middle tones versus walking over and turning up the light?

Mark

[Gunfitr]

Here you go, you have actually demonstrated my point.

You posted 2 images. Once dark and somber (and really cool to boot) and another that is more High key (and really cool too).

Open both in photo shop. Take a skin tone reading one inch above the belly button. In one photo, your skin tone is very bright, in another it is quite dark.

Assuming that was the same model, you can control whether that tone is a dark grey or a bright grey by how much light you pour on that area.

If you held a meter to that spot, you would get 2 different readings.

Is one wrong? No.

You are controlling the amount of light falling on your subject. In one case, a lot of light is falling on the model and her skin tone is brighter than the other.

Take the dark image and you could "brighten" her skin tone by either opening your aperature or adding more light.

Right?

Mark

[Doug_Lester]

Actually either will work, dependingon what you are after. For most general photography, ie portraits, etc, aiming it at the camera will read the being reflect4ed toward the camera. But if you are after some special effect, such as low key 'rim' light, aim I'll aim it at the light source, with the intent of having the background and shadow areas go black. IN the attached shot,I used two lights, each lighting different areas. Each was metered separately, aiming at the light itself, one at a time while shading the other light.

[Doug_Lester]

let's take an actual example.


In this photo I took a careful incident reading of the main light. That's the main and the setting I used on my camera. I then set the hair light, metered it and moved it until I got the same reading. If I recall it was f8 for each light, as metered. Now what would have happeneed if I altered the exposure to account for her dark skin? Why lighten her skin when I's natrually dark? If I had alterd exposure to lightened it, what would have happened to the background? It would have gone grey instead of black. What would have happened to the shadow on her torso? They would also go grey. If I had altered the aperture to cause it to go darker, I would have lost the subtle detail in her hair nd her nipple would have faded into the background.

Suppose I added baby oil, as I often do, tht would not have altered exposure at all, instead it would have added some glare, or spectral reflections depending on how heavily the oil was applied. Those are not a function of exposure at all.

Now if in this shot I wanted a more traditional portrait, I would have added fill light. Theat fill woul dnot have any bearing on my base exposure, I would still have used the same meter reading. Remember the main, fill and hair light are all lighting different areas so their effect is not accumulative.

If that piece of balck fabric you mentioned had been included, I would probably have added an additional light with a grid or snoot, more than likely placing it to the side. Again my exposure would not be changed as it would also be lighting a separate area. In that case I would gain some impact by having the light graze across the fabric to bring out its texture.

Now if you want it to be "whacky", there's absolutely nothing wrong with that and it might end up effective. You can alter exposure any way you would like, that's part of creativity. I've certinly done just that on many occasions, but keep in mind that if you tell someone tht is the correct way to do it, then it becomes an error.

It's tough to really give an in depth explanation in a forum post. The combination fo exposure readingd and the relationship between f stop and shutter used to be about a five hour lecture when I was teaching, complete with chromes as examples.

[Doug_Lester]

Nope, those two actually illustrate my point. They are different models. In the high key shot the model is quite fair while the low key model has a fairly serious tan. Each was exposed precisely according to the incident meter reading. In the high key shot three or four lights were bounced from the ceiling at various angles so the entire area was flooded with even light. In the low key shot, one light was used with a snoot or a grid, I forget which, and the incident reading taken from her belly. Both were exposed at f-8!

[cjeffries]

. . . who have posted in response to my question. I am very appreciative and am reading each with great interest. I have gained what I feel to be important insights.

To clear up a point or two. The Wein 1000 meter is an incident meter. It is fairly inexpensive as flash meters go. It displays only one reading at a time and I have considered getting a more sophisticated meter at some point when the budget will allow it.

"Back in the day" when shooting chromes, whether intentionally or accidentally if a shot was underexposed by a fraction of a stop to perhaps even a full stop, the colors seemed to appear more saturated and could have a pleasing effect on skin tones. In my limited experience with digital, an underexposure does not saturate the skin tones, but causes a shift to magenta. Thus the reaction I have is, turn up the heat. The model is cold. Well, she's not. If the lighting is uneven or the exposure is off, it's not the model who is cold, it's the lighting. Fix the exposure or fix the lighting. I've shot some stuff where the model's head and torso are fine, but her legs are another color. I realize now I had light falloff and the resulting color shift. In the future, I will light to correct that.

Again, back in the day, (in the darkroom) when printing B & W for display, I always strived for a full range of tones, from a solid black to a solid white, no matter where the majority of the tones may have fallen from light to dark. To my eye it just did not look right, as though darkroom technique had not been mastered without a saturated black in the print. This prejudice(?) continues with me as we all venture off into digital land.

This all having been said, I am again open to critique about how accurate my observations may have been.

Again, thanks to all who have posted. I am trying to digest it all and determine how to apply the knowledge and opinions you all have been willing to share.

Cheers,