Custom White Balance

[Kwazy]

I started using flash in my photography, and the white balance is pretty messed up. I've been dialing the color temperature down to make it passable, but need to get it right.
The few things I've looked at mention using 18% grey card to do custom WB, but the manual for R6 talks about a white card. I've used white card in the past on other cameras.

What is this 18% grey and how is it used?
How do you deal with white balance with or without flash?

 

[MikeZ]

an 18% neutral grey card is exactly that - a card that is 18% grey. It comes out of the old film days and is used to determine exposure based upon the optical theory that an average scene reflects 18% of the light that hits it (or is that it absorbs 18% ?). Anyway, hold that card under the same light as your subject, take a meter reading, and that will give you the "best" exposure settings. These cards do work since both film and sensors are based upon the same theory. Now, how that card will assist with determining the guide number for flash, I don't know. Sorry, but I know sooooo little about flash photography.

 

[Kwazy]

Looks like I got two concepts mixed up. Exposure metering and white balance.

 

[MikeZ]

I suspect that you need to work on the white balance using the white balance card. Like I mentioned earlier, I know so little about using flash photography so take whatever I suggest with a LARGE grain of salt. Perhaps this YouTube might offer some help: https://www.kenrockwell.com/tech/whitebalance.htm

There's a lot of basic info, which you probably know, but mid-way down he does address white balance for flash. Hope that helps.

 

[Kwazy]

Thanks Mike.

There are products that let you take a photo of a color card and then use the software to adjust WB based on what those colors should be. Examples are "Calibrite ColorChecker Passport Photo" and "Datacolor Spyder Checkr Photo." They're pretty pricy (~$100), but sound like a fool-proof solution to getting the colors perfect. Anyone have any experience with such things?