18% grey card

mikeanywhere

Where does someone get hold of one of these??

Fajitas!

Photography shops.

You can get them in the form of reflectors and lens cloths too!

rymus

while were on the subject (and not wanting to hi-jack the thread), anyone ever used one of those expodisks?

AlisonB

Why not just use a white bit of paper?

Valentia

AlisonB wrote:

Why not just use a white bit of paper?

Careful Ali . Have a look on PI when I made that innocent suggestion.

mikeanywhere

AlisonB wrote:

Why not just use a white bit of paper?

Because the 18% grey will enable you to get a much more accurate reading when setting custom whit balance. I was using white paper but was told otherwise.

tba

A good printer will get you an accurate 18% grey

AlisonB

Valentia wrote:

Careful Ali . Have a look on PI when I made that innocent suggestion.

I will have to investigate

Mikeanywhere wrote:

Because the 18% grey will enable you to get a much more accurate reading when setting custom whit balance. I was using white paper but was told otherwise.

Hmmm, i'm not convinced. I'll have to read up on it. My understanding is that any "gray" should have equal amounts of Red Green and Blue, as is white 255,255,255. So that said anything definied as "gray" that deviates from this suggests a cast?? I'm not sure what the advantages are of using 18% gray. I'll have to read up on it. Maybe my understanding is completely wrong?

mikeanywhere

AlisonB wrote:

Hmmm, i'm not convinced. I'll have to read up on it. My understanding is that any "gray" should have equal amounts of Red Green and Blue, as is white 255,255,255. So that said anything definied as "gray" that deviates from this suggests a cast?? I'm not sure what the advantages are of using 18% gray. I'll have to read up on it. Maybe my understanding is completely wrong?

I agree with you as I thought any grey would do but I was told specifically that it had to be 18% as that is the most accurate colour for a digi camera (not my words). I have also seen it mentioned on a couple of other websites so there must be a hint of truth in it somewhere.

bp_me

mikeanywhere wrote:

I agree with you as I thought any grey would do but I was told specifically that it had to be 18% as that is the most accurate colour for a digi camera (not my words). I have also seen it mentioned on a couple of other websites so there must be a hint of truth in it somewhere.

The manual for my camera says to use a white sheet for setting the white balance. Its a lot of effort when its easier to just shoot in RAW though....but thats a debate for a different day.

Roen

The Raw file records the white balance at the time of exposure, but doesn't apply it to the image so if you select the 'as shot' or 'camera' setting for WB in your conversion software and you had your custom WB bang on you should get great results everytime (should)
I posted links up to vids about this a while ago, they were basically ads for a WB product but were informative and simple to understand.

EDIT found em, check here
Scroll down a bit and check the four vids out, they're only a few minutes long and well worth watching. I'd like a product like that but in the weather I shot in the light changes so quickly that I'd have to have a shot for each condition on the day and would constantly be changing WB.

bp_me

Alternatively in the RAW post processor just use the white balance tool and click on whatever you actually want to be white. Or drag the slider around. (Photoshop RAW plugin anyway)

mike65

Print this

Mike.

Roen

mike65 wrote:

Print this

Mike.

Assuming your monitor/printer combo is properly set up and your paper hasn't any dyes in it to make it appear whiter
Although to be honest I wouldn't say the results you'd get from that grey square would be a whole lot different from any of the €50-100 gadgets you could buy. It's free, so you can print off a heap and if you lose it you can just pull another one out of the bag.

Good find Mike.

mike65

Back in the day when I was doing B&W I used nothing more fancy than the card of a tissue box!

Mike.

tba

A RAL colour sample sheet will work too.

Zillah

Oh for God's sake how ultra precise does the white balance need to be? Why is a piece of white paper not sufficient? Are your photos being analysed by Nasa scientists or something?

Roen

Far worse, boardsies.

mikeanywhere

Thanks for the vid link Roen

Thanks for the grey square Mike

Gyck

Oh for God's sake how ultra precise does the white balance need to be?

I'm with you on this one. Unless you're only ever going to display your stuff on your own precisely calibrated monitor or output on your precisely calibrated printer, who is going to notice?

Mind you, I'd still love to have that level of control

B0rG

well you noticed yourself that underexposure gives you that nice yellow tint

as for white balance set, it's good to have 3 cards:
white, gray and black, then you can just use Curves in photoshop to set black, gray and white points - piece of cake