Grey Area

[Keltic Ice Man]

I often read on sites about taking a reading off a grey card, and I believe the grey bag that some canon lenses are in is just the same percentage of grey

My question though is what do I do with this setting? Is it for processing? or is it for my camera settings?

Thanks

Confused as ever

 

[Puz]

From what I've read (not that I've ever done it) is that you take a pic of the grey card in the same light as were you are doing your shooting. Set the white balance in camera to the photo you've just takens and use that as the custom white balance for the rest of your shots

 

[RobertP]

If you are shooting RAW you can use the dropper tool (well you can in rawshooter) to pick the white balance from something white or grey in the shot. So if you have your grey card in one shot under certain conditions you can set the WB for other shots there to the same figure.

Or as Puz says fill a frame with the grey card*. Select custom white balance on the menu and choose that shot. Then go to the WB choices and choose custom. Just remember to do it again or go back to auto when you go somewhere else with different lighting.

Least that is the theory for custom WB I think as I've never actually tried it

edit * think it might just be the middle of the shot. need to check that.

 

[Keltic Ice Man]

Thanks guys - big gig tomorrow so useful info

 

[CT]

The grey card reading is primarily for ascertaining exposure settings in the camera.. Have read of this link.

CLICK

It's a bit basic but gives you the general idea. A Google search on 'grey card reading' will throw up lots of more in- depth reading.

 

[dazzajl]

Grey cards for exposure are not the same as a grey patch for colour balance. An exposure grey card only needs to have a certain lightness value. If it has a slight bend towards any colour, it's not going to effect the exposure reading at all.

When it comes to colour balance, the card needs to have totally identical values for red, green and blue.

Also, i've not set a custom white balance on the canon kit for ages (odd seeing as how it's step 1 on every shoot with the leaf back) but don't you use something white, rather than something grey?

 

[CT]

) but don't you use something white, rather than something grey?

Indeed. I do anyway, as it's simply telling the camera what white should look like in any given lighting conditions.

 

[CT]

What you should do as a simple demo of the problem is fill your viewfinder with something white - sheet of paper perhaps and take your shot. Do the same with something black - your monitor screen (switched off ) perhaps. Both your shots will look pretty identically the same shade of grey.

You can mess about with the eye dropper in RAW till the cows come home, but you wont get it right - it's not a WB problem it's a basic exposure problem. In both cases the camera meter has done what it's designed to do - decided that both images are 18% grey.