Blackmagic Forum

I second Marshall and Jamie's posts. Thanks much Ben. I can do PayPal when you're ready.

This sounds great. Thank you so much for doing this for us. I will pay you as soon as you want, Paypal or sending a check in the mail is best for me, but I will try to accommodate whatever method you want.

Cheers,
Virgil

Yes, thank you Ben!
Cheers

The wire payment was initiated at 3pm on Friday, Aug. 30th. However, due to the approaching weekend, the international processing of wire transfers was already suspended. I contacted my bank this afternoon to check on it and was informed that the payment went through successfully. So... I'm now awaiting Fotowand's confirmation of payment.

You're awesome Ben. Thanks for helping us all out.

Yes, thanks again Ben.
Cheers

Hi Ben,
the cards leaved, tracking ID is:
CY 54 963 513 5DE
wish you my best with them, Dietmar

I'm presuming the payment was successfully received since the above message was waiting for me when I checked my email this morning. The tracking number doesn't appear to be logged yet with German Post.

I'll get the final cost per card calculated and share it here for future reference. And, I'll PM everyone that participated in this purchase with details on handling reimbursement and getting your card(s) to you once they arrive here.

For anyone in the US reading this thread that might want to place their own order, the total for the ten gray cards came to 434.41 EUR including shipping and insurance to Colorado. The exchange rate at the time of payment converted the Euro amount to $524.20 USD. Payment via wire transfer (including the currency conversion) added another $55 USD. This brought the total purchase price for 10 cards shipped to me in Colorado to $579.20.

The resulting cost per individual gray card was $57.92.

Looking forward to getting the card, testing it, and using it on the next project.

Anyone tracking the shipment to date? Hopefully it is somewhere in the United States by now. I'm excited to try it on a project I'm starting this end of month. Hopefully it arrives in my possession before then.

In prep for the WB card to arrive, I've been doing some reading of their documentation online and one thing struck me. On the Blackmagic cameras like the P6K that has AWB, can I use the 4930 card with the AWB - obviously positioning the AWB square to the card as the subject holds it and update the WB for the shot?

Sure you can, just avoid the colored patches.

The whole idea of the card is that IN TOTAL it adds up to 18%.

If you can have the cursor fill the entire card.

Or just have sample be from only the grey part of the card.

Rendering that the way you hold and present the the card to camera is almost as important.

JB

Sure, if it fits you can include all of the patches. Unfortunately, being intended for photography, it's not 16:9.

Another suggestion: break it up (easily done by first scratching the back with a ruler and a knife) and rearrange the parts on some kind of neutral plate so that the colored patches are arranged horizontally.
This would make it easier to check them in the waveform.

I know, it hurts doing that to it when you paid that much.

Or you can just turn 90 degrees, zoom in and slide it up and down.

It also depends somewhat on workflow you follow.

I’ve never ever used WB in-camera.

But I always shoot a grey card for reference.

JB

Thanks Gents! What you said all makes sense.

Hopefully Ben's got the stash from Germany by now. Last I checked on the tracking info was in the process of being delivered to him.

I'm pleased to report that the shipment of grey cards arrived this afternoon from Germany in good condition.



I was able to scramble, repackage, and ship out grey cards for everyone from whom reimbursement has been received to date. I'll send out a PM with tracking information on the cards that shipped.

This whole tread is interesting and I'm very interested to hear what the results are like working with these interesting cards. But I thought I would ask a slightly "meta" level question about "what is white balance?" Generally we are dealing with red, blue and green filtered sensors, then storing that raw data in some form, then processing it into a resulting RGB human-viewable format. A "white balance" setting/adjustment is applied to the raw sensor data in generating the RGB result.

Can we accurately sum up this up by saying that for a given white balance (K) value and tint value (green/magenta +/- number), we are applying a filter or curve to the red channel, the blue channel and the green channel to get the resulting RGB image?

Tom Donalek wrote:This whole tread is interesting and I'm very interested to hear what the results are like working with these interesting cards. But I thought I would ask a slightly "meta" level question about "what is white balance?" Generally we are dealing with red, blue and green filtered sensors, then storing that raw data in some form, then processing it into a resulting RGB human-viewable format. A "white balance" setting/adjustment is applied to the raw sensor data in generating the RGB result.

Your question is really around workflow.

As I mentioned, I don't ever white balance on set. When shooting RAW all of those WB controls can be applied later. A grey card in scene though gives you a good reference for what's going on with the lighting. In theory you can do a POST WB using a grey card, as long as you photograph it in the right way.

Adjusting your camera RAW controls and even doing primary correction in Resolve (for example) later with this reference card in the shot will help you determine what's happening with the lighting.

In colour correction we often start with what's "correct" but a VAST majority of the time, that's not actually what "looks good"

They grey card helps you get it correct but this is really only a starting point.

The only time it would make sense to WB on set would be when shooting for a non-graded final delivery, and perhaps if you're shooting a format like ProRes. Even when shooting ProRes I still tend to shoot only two whitepoints and then do everything else colour correction wise later on.

Tom Donalek wrote:Can we accurately sum up this up by saying that for a given white balance (K) value and tint value (green/magenta +/- number), we are applying a filter or curve to the red channel, the blue channel and the green channel to get the resulting RGB image?

The white point is about balancing the RGB gain / channels in the camera / file so that the colour result most accurately represents what was photographed.

A vast majority of the time the light being used has a lot of imperfections and we can also try to a accomodate for that as well. The additional dots on this particular grey card are intended to show these colour bias in the LIGHT SOURCE.

The camera has to be colour balanced. But the light has to emit enough in a give part fo the spectrum to then LIGHT the object your photographing in that colour.

When you shoot with a very poor spectral light such as sodium vapour, you might be able to hit a white point (lets' say 1900K) but it's still going to be what it is. A very green / orange light with little spectrum to show all the colours that are in the scene. BUT using a grey card, you'll have equally balanced the response of the RGB challenge, and thus you'll have equal noise in each and in theory optimised the available DR.

And I'll re-iterate. When it looks right, and is correct, it's usually the most visually boring.

JB

John, would it be correct to take/shoot a few frames of this card for post processing? I don’t have to adjust anything in camera as far as white balance goes. I’m talking about shooting in natural light.

Thanks
Chris

Just got my card. Really interesting that's for sure. Thanks again Ben.

Creative110 wrote:John, would it be correct to take/shoot a few frames of this card for post processing? I don’t have to adjust anything in camera as far as white balance goes. I’m talking about shooting in natural light.

Not being John, but I'd say that's fine. We do that regularly and with only the waveform and playing with color temp and tint I can get the gray to a pretty flat line, which means neutral.

But then, natural light doesn't always mean neutral. Be careful with stray light from objects around you, which can make you overcompensate. If you have a lot of plants around, for example, you can easily get pinkish skin colors if you care for gray only.

Ben, Got my card today. Thank you so much for doing all the purchasing and handling!!!

Better to remain silent and be thought a fool than to speak and to remove all doubt.

And, here goes anyway.

One interesting observation when using the grey card to conduct an in-camera white balance versus using the white side of an x-rite color checker video card...

I set up a card holder stand straight on into full sun on a clear day. The URSA 12K was tripod mounted and framed up so that the white card and grey card both fully filled the WB sample area (no black frame on the white card and no white frame on the grey).

I activated the WB on the white card, hit record, and then swapped the white card with the grey card.

Next, I activated the WB on the grey card, hit record, and then swapped the grey card with the white card.

Interestingly (to me, anyway), WB on the white card provided a perfectly flat, white line (eg. aligned RGB levels) in the RGB parade scope, but the grey card RGB levels under that WB setting were quite obviously not aligned and showed distinctly different red, green, and blue levels.

Conversely, a WB on the grey card resulted in a perfectly flat, white line in the grey area (with flat lines above and below the grey line for the +/- 5% dots) on the scope, but the white card RGB levels were no longer aligned.

Also, the color balance (*K) and tint values changed quite a bit between the above two auto WB actuations. Visually though, the two shots looked pretty much the same on the color chart.

Bear in mind that until purchasing the 12K, I've really only used non-raw cameras - typically broadcast models. So, I'm expecting most of you will not be surprised with these results. I freely, if a little embarrassedly, admit to being a relative novice in RAW workflow. Please just allow for my learning opportunity and voicing this in my effort to better understand things. From my earliest tube cameras to my last HPX P2HD model and even my Phantom, my mental process has always been that the white balance on a white card was most important to get rolling and that you let everything else fall as it may from there. Having this grey card is forcing me to question that assumption and just possibly learn something new. Who knows what else I might be able to unlearn?

What I think my take-away from earlier discussions in this thread and elsewhere and this rudimentary experiment of mine should be is that using this particular grey card as my balance reference ensures that the middle grey / skin tones are the most technically accurate (which John rightly comments should only be your starting point). You can fix the highlights later. However, just using a white card for your WB setting will give you balanced highlights at the (likely) expense of properly balanced skin tones and possibly everything else. AND, the even better option is to simply shoot both the grey card and white card (and probably the color chart) to provide a starting reference for middle grey and highlights in post.

The majority of what I do probably doesn't require this level of workflow. And yet, I want to learn, grow, and understand those things that I don't know so that I'll be a better service provider for the clients I have.

#FoolDoubtRemoved

Great to hear your thoughts on this Ben.

I’ve never ever done WB on set. But it’s useful to record a card and then grade to it later. This card for me helps me understand what’s going on in the lighting.

JB

In reply to Ben — I've noticed the same thing on multiple camera models from BMD and Sony and Canon too — when middle grey RGB is balanced, diffuse white is not equally balanced.

I also noticed just this week that the Fotowand grey is roughly 500 Kelvin cooler than the middle grey on the 3 different DSC Labs charts that I have. My DSC Labs charts all match each other, and I'd bet that DSC Labs has middle grey absolutely neutral.

JB, have you compared the Fotowand to other color charts?