18% grey and metering

Big Mike

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This is to meter for exposure, correct?

So, in terms a simpleton would understand:

1. Arrange the subject (human) in the pose/composition you want.
2. Have them show you their palm.
3. Set the shutter speed and aperture in a way that indicates a correct exposure.
4. Step back and fire away, using these same settings.
Yes, this is to meter for exposure. A palm is about one stop brighter than 18% grey...so you would meter off of the palm, then add one stop, then fire away.

I assume this method is only for taking shots of people?
No, this can work anytime. If you are taking a landscape shot, you can meter off of your own hand, add one stop, then take your shot. You are essentially measuring the light, (not the subject) if the exposure is correct for the light, it doesn't matter if it's a person or a landscape etc.

Of course, you (as the photographer) have creative control and can over or underexpose as you see fit. That's why I don't get too caught up in metering...especially with digital. If I want more detail in the shadows, I'll expose for that. If I don't want to blow the highlights, then I'll expose for that.

Normally, I try to 'expose to the right', which is to get the shot as bright as possible but without blowing the highlights. Some cameras, (Canon 40D/50D) for example, have a 'highlight tone priority' which actually set the exposure to do just that.
 

Jon_Are

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I appreciate your helpful responses, Mike.

"Expose to the right" / "Add one stop" - means the same thing?

And what it means is this (?): Meter so that the in-viewfinder needle is one mark (literally) to the right of "correct" (or center).

First, do I have the above understood correctly?

Second, this seems to contradict what I thought I knew about exposure; that is, it's better to under-expose than over-expose because under can be corrected in post-processing (esp. when shooting RAW), but if an image is over-exposed, you're screwed.

The more I learn, the more confusing it gets.

Jon

Edit: Alright, I just read the link Mike provided in one of his posts (expose to the right), and it's starting to sink in: it's best to get pretty close to over-exposing, but don't actually blow out any highlights.

I'd still like the questions in the first part of this post answered.
Thanks.
 
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Josh66

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Grey cards are primarily used for exposure...and have been used for decades. Using them for White Balance is rather new because digital cameras have a variable WB. I've used a white card (or white anything) for setting the WB...but never a grey card.
I use a grey card (actually a "WhiBal" card, but pretty much the same) for white balance, works perfect. The only reason (I know of) not to use a white card is that it could get blown out much easier than a grey card, making your white balance reference shot worthless - R, G, & B values would all be 100%. With the grey card you don't run the risk of blowing it out, so those values stay closer to the 50-60% range (depending on exposure, of course).

Here's an example:

"As Shot"
IMG_5717-resized-small-2.jpg


White balance corrected
IMG_5717-resized-small.jpg


I just do a "click white balance" on the grey area.
 
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Josh66

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And what it means is this (?): Meter so that the in-viewfinder needle is one mark (literally) to the right of "correct" (or center).

Depends on your camera. Canon cameras show over exposure to the right, I believe Nikon is to the left. (Only talking about the light meter here - not the histogram, over exposure is to the right on the histogram.)

Also "one mark" is probably only going to be 1/3 of a stop (usually 1/2 stop on a film camera). There should be big marks and small marks, or numbers instead of big marks - mine looks like this:
-2 | | -1 | | 0 | | +1 | | +2​
^​

The numbers are full stops.
 
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gabrielh

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Still have a question: the quote from Mike:
"If I want more detail in the shadows, I'll expose for that. If I don't want to blow the highlights, then I'll expose for that."
If, say, you're shooting a black car and you want to expose for that, you put your focus point on the black car (say in spot metering) and expose accordingly. But do you subtrack a stop or two to get the car really black (otherwise, it would be grey, isn't it?)? Does is depend on the blackness of the car to subtrack a stop, half a stop, or more?
Same if you're shooting a white car, then you must take it into account and add a stop or two, isn't it?
So, when one says, "I meter for that or that", do one mean: "I put the focus on it, adjust shutter speed/aperture and then ALSO adjust some stop difference if the subject is quite white or quite black?"
Thanks!!
 

Jon_Are

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Maybe it's just me, but I see the uncorrected image as having much better color (aside from the card having a beige tint).

Take the card out of the shot and I think most people would prefer the colors of the top photo.

Jon
 

mrodgers

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Maybe it's just me, but I see the uncorrected image as having much better color (aside from the card having a beige tint).

Take the card out of the shot and I think most people would prefer the colors of the top photo.

Jon
I would say, if that is the look you are going for, then there's nothing wrong with having a warmer white balance. That is after all one reason why there are warming filters available and why people like to shoot in the warm light of the golden hour (hour after sunrise/hour before sunset.) But there are times you also want to have an accurate white balance.

What I wonder as I've read about white balance and using these cards that I've been reading for a year is, do you have to be using a RAW converter (such as ACR) to adjust with this method of shooting a white/grey card? I know you can change white balance in Lightroom, but I've only seen a slider and haven't found a way to do it by selecting on a shot such as jeepman there posted. I haven't seen a way to do it in photoshop either. The only thing I've figured in Photoshop was a very poor way of adjusting white balance.

I would like a way to adjust white balance accurately rather than moving a slider to where I think the white balance is correct, but I don't shoot RAW. I am wondering how you can do it with JPEG. Of course, please, no "it's impossible to adjust white balance in JPEG" comments. I adjust white balance and exposure in my JPEGs all the time. I just don't know how to do it with shooting a white/grey card other than using it to do a custom white balance in the camera.
 

Josh66

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You can use that card with RAW or JPG. In Lightroom (I'm sure Photoshop has it too, I just don't know where it is) there is an eyedropper next to the slider. You just click the dropper, then click the area of the image you want to white balance off of.

CaptureLightroomWB.jpg


You can use any software that has the dropper tool with the WhiBal cards (they make bigger ones too, I just like that credit card size one most of the time).
 

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