18% grey card help...

[troyer16]

I see people talking about metering off an 18% grey card. Is this to set the white balance for different light? For right now i am just taking a blank picture of a plain white piece of paper and using that to set the coustum white balance. Is this the same idea behind the grey card and same method you would use for the grey card? Thanks

[Curtis N]

A grey card can be used for metering or custom white balance. Some prefer it over white paper for a custom white balance because
1) White paper is easy to overexpose if you don't meter it right, and if you overexpose it too much, it won't be a good reference for a custom WB
2) White paper isn't always white. Sometimes they have bluing chemicals in them which will lead to a slightly inaccurate custom white balance.

[samnz]

My camera bag is grey. I think the original design was so to enable metering in the field. She's an old thing but it's bang on every time!

[tzalman]

My camera bag is grey. I think the original design was so to enable metering in the field. She's an old thing but it's bang on every time!

I could say the same of my wife:)

[jim9449]

A grey card can be used for metering or custom white balance. Some prefer it over white paper for a custom white balance because
1) White paper is easy to overexpose if you don't meter it right, and if you overexpose it too much, it won't be a good reference for a custom WB
2) White paper isn't always white. Sometimes they have bluing chemicals in them which will lead to a slightly inaccurate custom white balance.

Some guys say they meter from the grass to take sports shots eg. football,rugby How do they do this

[RichardStevens]

That may well be metering for green - which is described in the book 'Understanding Exposure' - if you aim at the grass, then configure your camera for a normal exposure, then take off 2/3 of a stop, this should get you a perfect exposure for green objects.

If I understand it correctly!

[PhotosGuy]

For right now i am just taking a blank picture of a plain white piece of paper and using that to set the coustum white balance. Is this the same idea behind the grey card and same method you would use for the grey card? If you're shooting on the meter reading & getting a gray pic, then yes. It's the way i do it, too.

Gray Card…White Paper. What’s best? (http://photography-on-the.net/forum/showthread.php?t=58677)

Need an exposure crutch? (http://photography-on-the.net/forum/showthread.php?t=89123)

Gray card: Why your meter may be lying to you! (http://photography-on-the.net/forum/showthread.php?t=54281)

[SAS]

I use a grey card for processing raw files.Photograph the card in the light your working with and then you can sample off it later to get the balances .You need to be running a processing software program like C-1 Pro or Adobe raw. Flex-color for the Hassy will do it but I find it to be slow and buggy. C1-Pro is just as slow, but a lot more reliable. Make sure it's a digital card and not one made for film. Total difference in the two types.

[Curtis N]

Some guys say they meter from the grass to take sports shots eg. football,rugby How do they do thisThey do this for metering, not white balance. Through experience, they know how the grass compares to 18% grey and adjust accordingly. Unrelated to the OP's question about using a grey card for white balance though.I use a grey card for processing raw files.Photograph the card in the light your working with and then you can sample off it later to get the balances .You need to be running a processing software program like C-1 Pro or Adobe raw. Flex-color for the Hassy will do it but I find it to be slow and buggy. C1-Pro is just as slow, but a lot more reliable.Every RAW conversion software that I have heard of has this same basic feature. Everyone has their favorite.Make sure it's a digital card and not one made for film. Total difference in the two types.I've never seen a digital grey card. Can you post a link to the product you're referring to? Theoretically, anything that's truly neutral in color from black to grey to white can work for setting white balance if it's exposed correctly.

[Mark_Cohran]

Make sure it's a digital card and not one made for film. Total difference in the two types.

No, there's not. 18% gray is 18% gray is 18% gray. Digital or film, it matters not.

Mark

[SkipD]

Make sure it's a digital card and not one made for film. Total difference in the two types.There just ain't no such animal..... Somebody's spreading cow stuff somewhere.

[Phil Light]

There just ain't no such animal..... Somebody's spreading cow stuff somewhere.

Is it possible then that my car didn't really need turn signal fluid too then? :confused:

[SkipD]

Is it possible then that my car didn't really need turn signal fluid too then? :confused:I thought that, officially, that stuff was called "blinker fluid". At least that's what it was called when I was a kid.

[Phil Light]

I thought that, officially, that stuff was called "blinker fluid". At least that's what it was called when I was a kid.

Don't be silly. Everybody knows that's only for the hazard lights.

[PhotosGuy]

Is it possible then that my car didn't really need turn signal fluid too then? That's VERY rare & expensive stuff! I'm glad I've never needed it! :D