The Reason Why Some Kodak Gray Cards Say Open By 1/2 Stop While Others Don't

Started Nov 19, 2012 | Discussions thread
Mako2011 Forum Pro • Posts: 23,277
Re: Robin Meyers Imaging 4"x6" WB Cards

Detail Man wrote:

Mako2011 wrote:

Graystar wrote:

I prefer a reference called the Digital Gray Card (DGC) by Robin Myers Imaging. It's a 4"x6" plastic reference designed for setting white balance, so it's bright (like 30% gray) and spectrally neutral.

One question.

When using it to set a custom WB (pre), the manual calls to "frame the object so it fills the viewfinder". Do you find that difficult with a 4 x6 card?

Their store has a 4x6 and a 6x9.

Also, any problems simply ordering direct from their site? Thank you

Ditto Graystar. Have had a Robin Meyers 4"x6" WB card for years now. Less expensive - and very likely much more portable than the 6"x9". Had no problems with a credit card on-line order.

Reflectance coefficient is rated betwen 30% and 36%. WhiBal cards are higher (around 49% or so) - but the 33% has not been a problem with indoor lighting and my LX3 compact Custom WB. Better than a 18% reflectance card - and I think that many cameras have good automatic-gain-control in those Custom WB sampling modes. Potential measurement problems may well arise more from potentially saturating channels when sampling. Have gotten good results as it is.

The DMC-LX3 (and other compacts) use just a sub-portion of the image-frame to sample. My DMC-GH2 is the same. No problem getting coverage in that case. Only problem is if the camera itself (and it's proximity to the card) is blocking the illuminating light source to be sampled (thus altering the color temperature and tint).

I hear that the E-M5 uses the entire image-frame to sample. Might get a bit trickier with the 4"x6" there - but it sounds like you are hearing about working techniques that suffice for such cases.

Have shot RAW (with LX3 and now with GH2) for almost 3 years (UniWB with GH2). I don't use it much with RAW - I just wing it with the RAW processor WB Temp and Tint. Not a biggie for me.

But it is a good quality product, and would serve you well, I think. Nice non-reflective finish that can even be carefully "honed down a bit" (according to Meyers) to restore the finish. I keep mine in a 4"x6" transparent plastic cover - so have not dinged or dirtied the surface yet.

Thanks also for the update. I have a 18% I've been using but it's starting to wear and not reparable. I went ahead and ordered both the 4x6 and the larger. I have two sizes now and find the bigger one is nice to set in a scene far a first shot reference later in a multiple shot project. And I couldn't make up my mind as I do use both sizes now. Appreciate the help.

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