Help with metering to a grey card...

09/09/2004 07:41:35 PM · #1

I'm a beginner, so please be patient with me. I'm taking a photography class, and last night the topic was metering to a grey card. I was so excited to be learning this, because I know it's something that will improve my pictures. When we got to go up to the front of the class and meter our cameras, mine just looked completely wrong. I set the aperture to 5.6, and brought the shutter speed down to, like 1/30, so that my exposure on the grey card was at 0.0. Ideally, they say these are now the correct settings when shooting subjects in the same place with the same light, and that all your colors should be correct. Well, let me post my samples... (these are for sample-purposes only, I wasn't trying to be pretty with them.)

This is just a shot I took standing back from the table. You can see red and grey and in the bottom right portion, a little of the pink.

Once I metered to a grey card, I took the following shot:

This is supposed to be red, just like the red in the first photo.

Here's a better sample of the pink next to a black card:

This one looks okay, not overexposed...

But when I meter to the grey card, it looks like this:

Yes, that's the same pink card!!! AWFUL!!! So overexposed I don't know what to do with myself!!!

I'm shooting in manual mode, and all of my settings get reset everytime I turn the camera off and on. Plus, just to double check, I went back through and made sure something wasn't set in error... my instructors have no idea what's going on because they're not familiar with my camera... I've checked online and found a few articles that state that you have to set the white balance with the C-8080 (which I didn't do in the class) and that it does tend to slightly overexpose photos, but I wouldn't think to this degree!!

Also, in Program mode, the camera works very well... it's not like this exposure snafu is has been a problem I've ignored, it just started happening once I started trying to use the manual mode.

I know this is technical and no one owns this particular camera, but any ideas as to why this is happening would be much appreciated. I'm completely frustrated... it just doesn't make sense to me.

Anyway, thanks in advance!!

Sigma 105mm f/2.8 EX DG Macro for Canon

09/09/2004 08:13:51 PM · #2

anyone (she meekly asks but doesn't want to be too pesky)?

longlivenyhc

Canon EOS-300D Rebel

09/09/2004 08:20:20 PM · #3

i meter using a pringles lid, so i dunno much about grey cards and much about the C-8080

magicshutter

Nikon D70

Nikon AF Nikkor 50mm f/1.8D

09/09/2004 08:21:27 PM · #4

I don't use your type of camera, but try the exposure compensation (with the white balance). Maybe even try bracketing. i do know that it's a specific shade of gray, perhaps you picked out the wrong one :S

cpanaioti

Canon EOS-40D

Canon EF 70-300mm f/4.5-5.6 DO IS USM

09/09/2004 08:28:16 PM · #5

In P mode it's probably using auto white balance. Are you using the same in manual mode?

Here's something that may help with exposure compensation. Also, read the article linked to at the bottom of that page.

Ironworker

Nikon D70

Nikon AF Zoom-Nikkor 80-200mm f/2.8D ED

09/09/2004 08:35:00 PM · #6

Originally posted by annasense:

anyone (she meekly asks but doesn't want to be too pesky)?

I have had similar problems with my c-4000, when I use the one touch white balance feature indoors. Was the white card directly under the light source? Have you tried using any of the presets ? ie. sunny, cloudy, tungsten lighting. Also you can have the camera save your settings. It is under the mode menu, setup, all reset, change to off.

09/09/2004 08:46:55 PM · #7

Originally posted by cpanaioti:

This is from the article at the bottom of the page:
A digital camera uses white balance as a metering reference, instead of 18% gray. It wants to make a white subject white, while the film camera wants to make a medium toned subject medium, or 18% gray.

This fact wasn't mentioned in my class... is this true? If so, that could be a helpful point. Also, the article stresses the importance of white balance... so maybe that's all it is. I'll have to play with it at home to see if that's it. Thanks for your help.

Ironworker, we were metering off a grey card (and related to my above finding, should I be metering off a white card?). It was directly under the lights, parallel to them. Then I moved them and propped them up on the chalkboard rail, and the same thing happened.

UPDATE: I just got off the phone with Olympus and their suggestion was to do the one-touch white balance, which I hadn't heard of until you mentioned it, Ironworker! :) I'm going to go try some things... I really appreciate all your help. If anyone else has any other ideas that haven't been mentioned, I want to learn as much as possible to eliminate all possibilities... and get it right. :)

Canon RF 24-70mm f/2.8 L IS

09/09/2004 08:50:21 PM · #8

just continuing on with my train of thought, it would make sense if i was supposed to be metering from a white card... because if the camera was expecting a white card and i showed it a grey card, it would blow out anything lighter than that grey card. hmmmm... i wonder why my instructors are teaching us with the grey card... i guess because half the class shoots with a film camera... i'm feeling less frustrated all of a sudden! can't wait to go test it.

kirbic

Canon EOS R5

09/09/2004 08:52:43 PM · #9

In order to get the results you expect, you do need to have the white balance set manually to the type of light source. Some cams can also do a manual white balance setting using the gray card. If you do this, you'll get the most accurate WB setting, then you can meter the esposure using the gray card, while using this white balance. You SHOULD then get the results you expect.

Canon RF 24-70mm f/2.8 L IS

09/09/2004 09:07:48 PM · #10

Originally posted by kirbic:

Some cams can also do a manual white balance setting using the gray card. If you do this, you'll get the most accurate WB setting, then you can meter the esposure using the gray card, while using this white balance. You SHOULD then get the results you expect.

Kirbic, do you mean doing a manual white balance setting by pointing the camera at a grey card and reading it (instead of a white card)? Won't this make all the colors shift to a darker shade? (Or is it lighter?) If that's not what you meant, would you mind explaining? I'm getting closer to understanding. Thanks in advance for taking the time to help.

kirbic

Canon EOS R5

09/09/2004 09:10:56 PM · #11

I believe as long as the card is neutral, either a gray card or white card will work for the WB. You are going to set the exposure separately, and are only after the proper balance between R,G & B when setting WB.
Do review you camer docs, they may provide further insight into how this works on you particular cam.

Message edited by author 2004-09-09 21:11:38.

siggi

Canon EOS-10D

Canon EF 28-135mm f/3.5-5.6 IS USM

09/09/2004 09:17:18 PM · #12

On my finepix I set the custom white ballance on a white card (the whole frame filled with white colored surface or card.

I set the camera to the custom WB setting and press shutter release.

As far as I know you use the grey card for the exposure and white card for the WB, at least it seams to work for my camera.

edit: the ballance between RGB sounds logical.

Message edited by author 2004-09-09 21:18:15.