Understanding Exposure

[Jason Hermann]

Kelly,

WOW!! Nice work!! I think you nailed it for sure

So you just metered the gray card with your meter entering the Aperture you wanted? Then put the camera in Manual and set the aperture you wanted and the shutter speed to what the meter gave you (1/125ssec).

Do you think that technique will work in the harsh sun?

Thanks and Congratulations!!

Jay

[Wes]

Kelly, I try to meter for the highlights when using my handheld incident light meter. You can't recover the highlight detail if it's not there to begin with. Shooting digital, for me anyway is alot like shooting reversal film. Another tool I have found very valuble in the digital world is a calabration target by Ed Pierce (PhotoVision Targets). It is a great tool for custom white balance and exposure, both in camera and post production.

[Jason Hermann]

Thanks for the link Wes

Jay

[KellyL]

This is the same target used by Dean Johnson he references in his article. Any suggestion on the size needed? I am considering either the 14" or the 24".

Thanks Jay. Yes, you have it correct. Let me tell you, after all of my struggles I was nothing short of thrilled. Now I understand that whatever I am metering, I am telling the camera that this is where I want the midpoint of exposure to be. If I meter a highlight, I am telling my camera, this is the center of exposure. I can measure a highlight, open up one stop, still not blow out the highlight and bring more detail to the shadows.

THIS IS STARTING TO MAKE MORE SENSE!!!!!!!!!!!!!!!!!!!!!!!!!!

Thanks Felix and Jay for your continued support and conversation.

[Jason Hermann]

Seems like the most simple approach for sure!! a 2 second reading and your done. I need a gray card now

Jay

[kgphoto]

Kelly,

The Kodak Gray CArd is great for exposure, not so much for White Balance. The Whi-Bal is clearly superior here(WB), if only for the tested neutral consistency between individual units that the Kodak card doesn't have.

If you are going to take a reflected meter reading off a gray card, then you might as well use an incident reading at the subject using the Hemispheric Dome extended, not retracted and place the dome under the subjects chine and point it at the camera lens axis. It is faster and easier and therefore more accurate. The 3-D shape of the dome takes into account the shape of a face and does some of the averaging of the values to give you a good mid point.

HOWEVER, it will overlook completely the background values, hot hair high lights and any sun spots that hit wherever the meter isn't. Of course the Gray Card method will miss these very same things too.

One other thing, if you tilt the gray card so it reflects more light toward the camera, it will throw off both exposure and WB.

I have tried the Photovision Targets. The newer ones are better than the old models. Their main drawbacks are the time to use them and open and close them and store them and they are not three dimensional so they cannot see shadows under the hair along side the neck and things like that. They also have the same problems as the gray card.

IF you have calibrated your meter, lens and camera, you can get the same results with an incident reading for no more money and a lot of saved time. Additionally, you have the added benefit of being able to take a series of readings in reflected mode to insure the rest of the tones in the image fall withing your contrast range perameters.

I know i sound like a broken record here, but it is only because you seem to be ignoring the base line information that I am putting out there.

[Brooks]

Really! What Kgphoto said ! If you're going to use a grey card for your expopsure, you're better off using your meter in incident mode.

If you have a lot of light coming from the side or top, like the sun from behind the subject, just shield the dome with your hand, position it at the subject and point if back towrds the camera, press the button and be done with it.

[KellyL]

Brooks and Kirk: I have not forgotten what you have shared. What you have shared is too valuable. If I remember correctly, it was KgPhoto who told me to use a gray card for exposure. I knew I needed to do something better than I had in the past, and since I haven't had time to work the two methods you guys have prescribed, I went with the gray card.

Kirk: You have advised me to follow Lee Varis's book. It is very involved and I don't have a McBeth color chart.

Brooks: I am still planning on doing the tests, just haven't had time. I still think it would be interesting to test the DR of the camera to get a good feel for what I should be aiming for.

Both of you are correct. I don't know what to do with a background and multiple readings yet...but I am learning. This was a do or die situation and I needed something to work quickly.

Don't worry. I am not finished.

[heartseye]

As was discussed before....finding your cameras dynamic range just means shooting a grey scale......but you need to do it with every lens you have and, I hate to say it, at every f/stop. But...THEN you will know forever!
Of course once you know the DR...well.....just set the camera on "A" and let fly ---- Bob

[felix.reichardt]

Kelly, I have the feeling you think more complicated than it actually is. Why not use your meter as incident meter instead going the way more complicated route in spot metering a gray card as KGPhoto and others said which is exactly what the white dome on the meter does. Once that works for you you can go for more sophistic metering with ratios for highlights and shadows.

Use the gray card to get accurate whitebalance.

Just my thoughts. Cheers

[KellyL]

Okay...I did find where the gray card technique was suggested. It was in Exposure and Lighting Technique for Digital Photographers Only. The first part of the book informs the reader of the very rudimentary aspects of digital cameras, sensors, understanding ISO, aperture, and shutter speed. The next chapter discusses what an accurate exposure looks like. Then the book begins discussing how to expose, explains different metering systems, light meters, incident and reflective light and then presents the gray card technique.

The gray card technique worked very well for me when I was in a pinch and needed to use something quick and dirty for a photo shoot. However, what I did not like about ths technique, for outdoor portraiture, was that I had no idea what the background would look like. The LCD monitor was a poor rendition...and difficult to see outdoors. I knew that my subjects were looking pretty good, but I was also afraid that the background was going to be underexposed.

I need to correct something. Kirk didn't tell me to use the gray card. Kirk has discussed the use of the Whi-Bal card.

I now have a better understanding of the light meter and midtones because of our discussions here. As Felix pointed out, I could have used the dome to measure the incident light and proceeded from there. Knowing that I also needed to start using my gray card, which I purchased three years ago, for white balance, I decided to kill two birds with one stone. Meter the gray card and also have it in the fram for a white balance reference.

It is easy to get sidetracked. I have knee jerk reactions to suggestions and equipment.

[felix.reichardt]

Originally Posted by KellyL

I now have a better understanding of the light meter and midtones because of our discussions here. As Felix pointed out, I could have used the dome to measure the incident light and proceeded from there. Knowing that I also needed to start using my gray card, which I purchased three years ago, for white balance, I decided to kill two birds with one stone. Meter the gray card and also have it in the fram for a white balance reference.

Kelly, whatever works for you is great. Maybe you give your incident meter a chance and find out it's easier than to fidle with the spot meter. But hey - what counts is the result and if it looks good who cares how it was metered. And your posted images usually look good .

[JohnC]

Originally Posted by KellyL

The gray card technique worked very well for me when I was in a pinch and needed to use something quick and dirty for a photo shoot. However, what I did not like about ths technique, for outdoor portraiture, was that I had no idea what the background would look like. The LCD monitor was a poor rendition...and difficult to see outdoors. I knew that my subjects were looking pretty good, but I was also afraid that the background was going to be underexposed.

As I see it, in this situation all the meter could do would be to confirm your suspicion about the background being too dark. What would you do to correct the situation? Would you move the subjects to another area that was more balanced with the background? Would you put up some sort of flag/gobo/screen to lessen the light on the subjects? Would you somehow try to add light to the background?

What do you think would be different if you used an incident meter instead of using a reflected meter and a gray card?

[kgphoto]

Kelly,

I have mentioned using the gray card to you as an exposure device while differentiating it as a white balance device in some of our PM's that you erased. I didn't recommend it, as you already have an more efficient incident meter.

It is faster and easier to just do an incident reading while you are posing the subject than using a gray card and metering it. I did mention sticking a Whi-Bal in the scene and cloning it out later as a way to have a test chip in every shot to speed up post processing. The different sizes of Whi-Bals make that easy.

The MacBeth Color Chart is expensive and for someone who really wants to "know," invaluable, but it is $80.00 or so. You can do most of the calibration with everything else and just use your local lab to give you some densitometer readings of your own target to use as comparison. However, if you are going to be earning money from photography you owe it to your clients to be fully trained and they pay for it anyway so it is free.

But don't give me the excuse that it is too involved! If you want the fame, you gotta do the pain! And it really isn't all that involved. Once you start to go through it, you will be fine. I did my first calibration with a few colored handkerchiefs, a piece of Black velvet, a pretty girl along with a gray card and white t-shirt as my test frame.

Felix,

Brooks and I already told him to use his incident dome. We haven't recommend that he shoot gray cards, but take several readings of his scene so he knows the contrast and exposure range so he can set his camera and/or adjust the light to make the best picture... picture... picture... picture... picture

And a "Gray" card will not give you accurate color balance unless that card itself is color neutral. Most Kodak Gray cards are not. They were manufactured for exposure density not color.

There are several sellers of WB devices that fold and don't, and I have tested 5 of them. There are definitely differing levels of color neutrality. As long as the one you get is neutral, then you are fine. I personally have found, I like the consistency, convenience and quality of the Whi-Bal. The are easy to keep clean and durable.

Canons actually work best with a white card, rather than a gray card for white balance, if you are shooting in their normal settings with Jpegs. However if you are shooting RAW and or are not accurate with your exposure, a Whi-Bal is better.

[felix.reichardt]

Originally Posted by kgphoto

Felix, ... Brooks and I already told him to use his incident dome. We haven't recommend that he shoot gray cards, but take several readings of his scene so he knows the contrast and exposure range so he can set his camera and/or adjust the light to make the best picture... picture... picture... picture... picture ...

Yep, thats why I mentioned your name ...

Originally Posted by kgphoto

... And a "Gray" card will not give you accurate color balance unless that card itself is color neutral. Most Kodak Gray cards are not. They were manufactured for exposure density not color. ...

Guess mine is color neutral ... got mine from Frank Doorhof and I he is using it with great success - and so far works for me ... but I heard the Kodak one is not 100% neutral. Not sure what Kelly is using - maybe I missed the information here.

[jfrancho]

This is wayyyy more complicated than I ever imagined. It shouldn't be that difficult to get a decent picture.

No gray cards, GMB color charts, or handheld meters were harmed making the following pictures:









I generally use partial metering and use the thumbnail and histogram to verify my interpretation of the camera metering.

[brice]

Originally Posted by kgphoto

But don't give me the excuse that it is too involved! If you want the fame, you gotta do the pain! And it really isn't all that involved. Once you start to go through it, you will be fine. I did my first calibration with a few colored handkerchiefs, a piece of Black velvet, a pretty girl along with a gray card and white t-shirt as my test frame.

If I want to duplicate your technique, does the girl have to be pretty or can I use my cousin Helga Stinkmanly? Sorry I couldn't resist.

[kgphoto]

brice,
As long as she has a "normal skin tone" she will work. I chose a pretty one since I was going to be looking at these images a long time through a loop.

[Brooks]

That's not a very big fish. Just sayin'...

[jfrancho]

But this is....