Need an exposure crutch?

How would I use this "White to the Right" method with flash?

My 1-cent flash "meter" in images 5S & 6S.
Simple 2 Light Portrait Set-up

See post #3
Tips for Xmas Ball Please

coalcliff wrote in post #5681420
I was thinking from my biology days that the skin will change colour depending on the amount of 1- Blood flow
2- Sweat on it

So a hot day where the body is trying to dissipate heat the blood flow to the extremities is increased , as is the amount of sweat, should generate a different reading from the cold days where the flow to the limb limits is restricted.

maybe i should test this theory prior to posting......Nah live dangerous, i like eating words!!

It's not white balance we're going for here, it's exposure. The sweat might matter, but the color prolly wouldn't. I usually start my chimping for the histogram at something of a similar tonal range to the subject. Could be dry grass or shaded green trees depending on if the subject was dark or light. For exposure (vs WB) the reflectivity/luminosit​y is what I'd be concerned about. The 18% gray card can work for WB and for exposure (EDIT - I'm not so sure about using the gray card for WB, I'm confident in a white card for WB though), but not for the same reasons IMO. For WB it's the neutral colors that are a benchmark in a given light, for the exposure it's the consistent reflectivity/luminosit​y/tonality for a given light.

For anyone who's read this far & still doesn't "get it", maybe this thread will help:
GoingManual.com - Metering the Scene

He even used the lame joke I did!
He uses his hand to get a gray card reading, where I use it to keep white at the right because I shoot cars with partially blown chrome. The results will be similar, but not exactly the same.

tkoutdoor wrote in post #5709310
It's not white balance we're going for here, it's exposure. The sweat might matter, but the color prolly wouldn't. I usually start my chimping for the histogram at something of a similar tonal range to the subject. Could be dry grass or shaded green trees depending on if the subject was dark or light. For exposure (vs WB) the reflectivity/luminosit​y is what I'd be concerned about. The 18% gray card can work for WB and for exposure (EDIT - I'm not so sure about using the gray card for WB, I'm confident in a white card for WB though), but not for the same reasons IMO. For WB it's the neutral colors that are a benchmark in a given light, for the exposure it's the consistent reflectivity/luminosit​y for a given light.

tkoutdoor - Thank you!

I was trying to wrap my head around what people were saying here - maybe I read through it too fat - maybe I'm just too tired. But this sums it up in a nutshell. - If this info had been in the original post (or somewhere near the top) this whole thread would have been much easier for folks to follow. Thanks again!!

You don't want something of similar tonal range to the subject. The subject could be white or black, no? You want something constant that will give you an exposure without blowing ALL the whites. (Where blowing some highlights is OK.) Which is what your hand stands in for.

Again, remember that this is a starting point to shoot something with bright highlights. For subjects with reduced values, consider reading about Expose (to the) Right

PhotosGuy wrote in post #6085603
You don't want something of similar tonal range to the subject. The subject could be white of black, no? You want something constant that will give you an exposure without blowing ALL the whites. (Where blowing some highlights is OK.) Which is what your hand stands in for.

Again, remember that this is a starting point to shoot something with bright highlights. For subjects with reduced values, consider reading about Expose (to the) Right

The difference between a black plane at an airshow and a white plane at an airshow effects the exposure dramatically. I do mean "I start chimping with something of a similar tonal range to the subject". It's exactly what I do. I don't want to choose a dark clump of trees for comparison to a white bird, nor the sky for comparison to a black bird. If I know my subject is a white seagull or a dark colored hawk, I look for something in that tonal range for comparison. Reflectivity/luminosit​y is a part of this, but it's chimping after all and a similar tonal range (irrespective of its color) is the biggest factor I'm looking for. The white of the hand could be close enough for the seagull, but I would shoot for the dark green of a tree for the dark colored hawk. A dark bird has no highlights of consequence so I find that exposing for my hand isn't a big help.

If it's a potshot as to what the subject will be then something perfectly neutral would be more in order. Since this is chimping we're talking about then after a shot or two, taking a look at the histogram to see if adjustments might be in order would be something that I would do next before I get too many shots under my belt. I do "expose to the right" as well so I know to adjust accordingly either as an initial guess from the sample subject or from my evaluation of the histogram.

If I knew that everything would fall within a usable tonal range either because I could flash to compensate or because nothing was strongly backlit then I'd see the gray card/hand as a good solution for exposure (not WB). With strongly backlit subjects (things that fly in the sky) where you know you stand to have to choose between either the subject or the sky, it has to be the subject that I pick. I can't favor the sky at the expense of the subject and then lose the subject. If I had to balance both darks and lights like in a wedding situation I wouldn't have to be guessing I think, I'd have the actual subject at hand and could meter or chimp from the actual subjects. Your mileage may vary, but that IS what I do and I am of that crowd that "exposes to the right".

Your suggestion is that whether dark or light the hand works for either? Am I understanding that correctly? I can't get a long lens to focus on my hand because the MFD is oftentimes out of reach with long focal length lenses, so I seldom bother with my hand. Technically it prolly doesn't have to be in focus, but my camera doesn't want to fire without special gyrations like MF, so I use dry grass instead of my hand (when my subject is similar).

rmford wrote in post #3871647
Does anyone with a Lowepro slingshot bag and an 18% grey card want to do a comparison between them?

I imagine that if it was pretty close, or dead on, lowepro would be more than happy to tell us about it, but you never know.

I lost my gray card at a wedding last week, but I had to give the Lowepro gray a try. Much closer to the true color than the auto setting. Think I'll pass on getting a new card. Would like to see a gray card included in a comparison.

Apshiso wrote in post #6085010
tkoutdoor - Thank you!

I was trying to wrap my head around what people were saying here - maybe I read through it too fat - maybe I'm just too tired. But this sums it up in a nutshell. - If this info had been in the original post (or somewhere near the top) this whole thread would have been much easier for folks to follow. Thanks again!!

You're Welcome. The differences between shooting for exposure and shooting for White Balance are kind of crazy at first unless someone tells you they're different and you should expect different results for each. Glad you found it to be workable.

No, it's not. The only chimping you needed to do was in the first step to see where the needle will be when you use the same settings when you read your hand. You never need to chimp again.

It doesn't need to focus. It's more like an averaging incident hemisphere when the hand is out of focus, & why would you want to take a shot of your hand, anyway? What good would that be? You're just using your hand to adjust the needle to the exposure you found to be correct when you chimped the white exposure which you could have done a year ago when you bought the camera.

I did say that my method is a starting point? I'm assuming that someone using it will apply a grain of common sense & adjust for extreme conditions as you do.

thanks i needed this

I have always been using EC until i read these threads which points to me the time i have been spending per shot is way more and & not correct. [70% of the time shoot M mode and 30% AV , do not use TV at all]

Have been reading the threads related for 2+ hours now. I have a quick question / rather easier thinking, pls correct me if am wrong

all we are doing is simulate an exposure reading off a 18% gray card and instead using the palm, notice how many stops you are overexposed and just continue to use the same exposure reading. Meaning - on all my subsequent shots the needle will be in the overexposed territory 1 - 1/3 stop whatever it maybe ?

Questions : -

A. -- I have a real dark palm [In terms of skin tone], does that really matter ?
B. -- This method is almost close to EC (but gives the adv of correct exposure right on), i have seen on 1 - 1/3 stops over, highlights are blown at several places. Now thats not a frame where the subject to background contrast is high. In such a scenario, Do you continue to adjust your exposure even when
exposure reading is taken off the palm ?
[I want to try out tomorrow morning to post results]

So, just to start off with, will a plain white injket printing paper (rough side) or an art paper (available at Michaels or Walmart) be used for both adjusting Custom WB and exposure [Yes i did read that neutral gray paper is needed for WB and 18% gray card or white card is for exposure, so i get the differences. Its just that i cannot justify spending $$ on buying a card, if i can get close to approx values and do the rest at Photoshop - Am i being reasonable in my thinking ?]

Please advise

My 2 cents....

A If your skin tone is dark then it does matter. The rule for a regular caucasian palm is to meter off you palm and set an exposure that puts the needle at approx +1 to +1.3 stops above the middle, perhaps even +1.7 stops higher. If your palm is a bit darker than a "regular" caucasian palm then you would reduce the exposure a bit, maybe to +0.7 to +1 stop.

B It's not so much that this gives you an "accurate" exposure, although that will tend to be the case, but rather that it gives you a straightforward and repeatable target for setting exposure that you will always have with you and which costs nothing at all. If you have a scene that is tricky to meter, for whatever reason, your palm will provide a reliable and known metering reference ( so long as it is in the same lighting as your subject/scene).

In my opinion, and some would argue, you can use plain white paper to set both white balance and exposure. The argument about WB is that you can question whether or not the paper is truly pure white. Well maybe it is and maybe it isn't, but hopefully it will be damn close and a much better reference than taking pot luck with AWB or even a preset, which may or may not match the lighting conditions perfectly. In order to use the white paper as a WB target you need to use an exposure that renders it as middle grey, not white, so a reguar auto exposure with 0 EC, or a manual exposure with the metr centred, would be fine for that.

As for using white paper as an exposure target, consider this - brilliant white paper is going to reflect light well and will be pretty much as bright as any other reflective object in a typical scene. It is true that specular reflections of the sun, or other light sources, from glass and metal may well be brighter, or even a shine from white paintwork or the sheen from satin, but the white paper will be close. Your camera should be able to capture highlight detail up to about 3.3 stops above middle grey. If you use the paper as an exposure target, and set the exposure to give a meter reading of +3 stops, you will position the exposure for the paper very close to the right hand edge of the histogram. You will retain 0.3 stops of headroom for anything that is even brighter than the paper and pretty much everything in the scene will be captured as bright as can be without overexposing. This will do wonders for noise control and maximising tonal detail captured. If you shoot raw and there is actually nothing in the scene itself that is especially bright/reflective (apart from the paper target) then you could actually push the exposure even higher, to maximise your "expose to the right" data capture.

As always, use the histogram to double check that your exposure is sound, before rushing off and churning out a few hundred shots with the exposure just slightly off. Chimp occasionally to make sure the lighting hasn't pulled a fast one on you and changed without you noticing.

tdodd is partly right, but he's missed the point in this thread. You've already compensated for the difference in #2 on the first page:
If I set the #1 exposure in the camera & look at where the needle is while the camera is pointing at my hand, mine shows overexposure (the needle is more than 1-stop to the right.) Remember where your needle is!
The difference between #1 (proper exposure) & #2 (what the meter thinks is correct.) is 1-1/3 stops, or 4 clicks, & is my personal “palm” compensation factor.

You have to decide what highlights you need to keep & which ones you can let become blown out. Remember I said that this is a starting point to find a constant that you can rely on. Then you need to engage your brain & experience.

Yes.

A good point, but remember that we may be letting some things like chrome become blown out, so the histogram will 'reflect" that. But it's always a good idea to check your hand from time to time. I use it to get the exposure for car interiors, under hood motor shots, etc.

<PS : I was away for sometime due to tremendous work pressure at office, hence could not do any tests>

Thanks Frank, So i did some tests today at the front porch of my house. [Pls note : out of the same white paper, i made my camera's custom WB, histogram perfectly at center]

Apologize for the horrible OOF pics, i had only a cellphone camera.

My setup : 5D+24-105mm f/4L on a tripod ; stacks of white paper.
Setting used : M mode, 105mm, f/5.6, MF
Distance : 7-8 feet

<CAMERA Setup>

Yes, in this case.

Look at your last image. You had different light at the camera than you had at the paper. Remember in the 1st post I said in bold type, "in the light that’s hitting the subject"?

You took the loooong road to get there, but that sounds about right.