PADI Photographer White Balance Slate - Gray Scale

I have a PADI WB Slate (69231). I'm playing around trying to determine if the gray side (marked as Focus Control) is also the gray for WB in post processing. I'm using Oympus Viewer 3 and it only has a WB option for gray. See https://b2bap.padi.com/ItemForm.aspx?item=69231K&Category=cea3ba12-c4ba-4381-9829-7488da47a65a.

Thanks

What camera are you using?

Bill

Bill, I have a Canon E-PM1 in which I can set WB I know albeit it being finicky in accepting the card shot.

I did get an answer from Olympus that there 'gray' WB setting doesn't need a specific % and also suggests if you have multiple grays you play around to get the color you want.

This is only for my travel notebook. At home I use LR.

Do you want to be a real dweeb about this?

Good, here's how.

Assuming you have an 18%, take it to a modern paint store, the type that has a colorimeter and have them measure the actual colour. Then have them do that to your PADI card.

Failing that, some print shops should have this type of equipment.

https://nixsensor.comsells inexpensive devices that attach on to your iPhone or Android phones. But that is getting to be overkill.

'Grey' for White balancing isn't a specific 'grey', can by 18%, can be anything really - the main issue for using a grey card for white balancing is that the card is completely Neutral, so the R,G,B values read off of it are the same - The PADI card is indeed pretty neutral - and its a Matte finish too, which helps.

The only issue I would say with the PADI card, is thats its quite dark (for grey) - so some cameras might not like it and refuse to WB off, of it.

Don't forget its a $15 card also - they will not be checking the consistency of the neutrality of their cards, unlike XRite or DSCLabs - but for us underwater I think its pretty close.