Grey card

[Ronaldraw]

Advertisement (gone after registration)

In the settings of white balans there is the option Grey card. Is it correct that I have only to shoot one Pic through the Grey card option and that's it? 

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[IkarusJohn]

When you select the grey card option, you then hold the grey card in front of the camera and fire the shutter.

That gives you the colour balance for the light that you hold the card in.  So, if you’re in the deep shadow of a building (say under an eave) and you set the white balance in the shade, but photograph the sunny scene out of the shade, the white balance setting is unlikely to be accurate.  For an accurate reading, you need the white balance to be set (hold the card) in the same light as your subject.  As the light changes, so will the white balance setting, if you want it to be accurate.

Back in the days of using a Hasselblad 503cx and a Gossen 1º spotmeter, I had some 18% neutral grey sticky pads (like postits) I could stick on the subject to get an accurate light reading (then take them off for the photo, obviously).

The simple point - the reading is only useful if it’s of the light your subject is in.  With modern cameras, most of the time if you just set the colour balance at 5,500K or whatever suits, you can then adjust in post.

[Ronaldraw]

35 minutes ago, IkarusJohn said:

When you select the grey card option, you then hold the grey card in front of the camera and fire the shutter.

That gives you the colour balance for the light that you hold the card in.  So, if you’re in the deep shadow of a building (say under an eave) and you set the white balance in the shade, but photograph the sunny scene out of the shade, the white balance setting is unlikely to be accurate.  For an accurate reading, you need the white balance to be set (hold the card) in the same light as your subject.  As the light changes, so will the white balance setting, if you want it to be accurate.

Back in the days of using a Hasselblad 503cx and a Gossen 1º spotmeter, I had some 18% neutral grey sticky pads (like postits) I could stick on the subject to get an accurate light reading (then take them off for the photo, obviously).

The simple point - the reading is only useful if it’s of the light your subject is in.  With modern cameras, most of the time if you just set the colour balance at 5,500K or whatever suits, you can then adjust in post.

I would photograph hair braids as produciton, made of real hair. I did this in the same way with the gray card. The colors didn't match in Lightroom anyway. I had to edit each photo separately. It was quite a task. There were 60 pieces in total.

While taking the photos, I did check in the camera if they were good and accurate. Something probably went wrong in Lightroom.
 

[jaapv]

My main use is when I have "impossible" light, like LED that seems bright yellow. I will use anything that is more or less monochrome, like a white tablecloth as grey card. It will get me in the ballpark to edit to an acceptable colour rendering.

[david strachan]

I always carry a clean white handkerchief.  Has been an excellent grey card substitute on many occasions.

...

Edited January 18, 2024 by david strachan

[Qwertynm]

Always thought an 18% greycard was to meter the scene not measure the white balance. 

[evikne]

Advertisement (gone after registration)

5 hours ago, Ronaldraw said:

In the settings of white balans there is the option Grey card. Is it correct that I have only to shoot one Pic through the Grey card option and that's it? 

On my M10 (I assume the Q is pretty similar) I do this:

• When you have taken the picture of a neutral gray (reference) surface, use the direction pad to move the small crosshairs to the subject detail you want to use as the basis for the new white balance setting and press the center button. You may see the white balance change. Press the center button once more to save the new white balance.
• Make sure that the white balance is set to "Greycard" before continuing to take photos.
• In Lightroom, use white balance "As Shot".

Edited January 18, 2024 by evikne

[Ronaldraw]

25 minutes ago, evikne said:

On my M10 (I assume the Q is pretty similar) I do this:

• When you have taken the picture of a neutral gray (reference) surface, use the direction pad to move the small crosshairs to the subject detail you want to use as the basis for the new white balance setting and press the center button. You may see the white balance change. Press the center button once more to save the new white balance.
• Make sure that the white balance is set to "Greycard" before continuing to take photos.
• In Lightroom, use white balance "As Shot".

Sorry, I don't understand. It's my English. Would you please write it again so I can understand. Sorry for asking 🙏

[evikne]

50 minutes ago, Ronaldraw said:

Sorry, I don't understand. It's my English. Would you please write it again so I can understand. Sorry for asking 🙏

I don't quite understand what you don't understand. If the colors don't turn out as expected when you've used the gray card option, there are three places where things can go wrong, those are the three points I mentioned.

First, you need to ensure that the new white balance is saved correctly.

Second, you need to use the new white balance when shooting, and not Auto White Balance or anything else.

And thirdly, you need to use the same white balance when editing the images in LR (As Shot).

And of course, as others have mentioned, the gray card (or whatever you use as a reference) must be held in the same light as the subject, and the light must not change while shooting. 

Edit:

I thought of yet another possible source of error: The gray reference surface must of course be really gray and not contain any color tints, otherwise the white balance will be wrong. I use a high quality white balance card from WhiBal that fits in my wallet and is always ready to use.

Edited January 18, 2024 by evikne

[jaapv]

2 hours ago, Qwertynm said:

Always thought an 18% greycard was to meter the scene not measure the white balance. 

Any other neutral surface will serve but with a grey card-although it is meant to assist exposure- you can be sure it is real gray. 

[david strachan]

2 hours ago, david strachan said:

I always carry a clean white handkerchief.  Has been an excellent grey card substitute on many occasions.

...

Ooops, I meant White Balance measurement off the handkerchief, sorry....not Grey Card which is of course just exposure level.

 

[Qwertynm]

vor 3 Stunden schrieb jaapv:

you can be sure it is real gray. 

Thought white balance meant to balance off white. Grey would give too warm of a tone, no? I have no experience with grey/white cards so I‘m asking out of curiosity 

[RobW0]

39 minutes ago, Qwertynm said:

Thought white balance meant to balance off white. Grey would give too warm of a tone, no? I have no experience with grey/white cards so I‘m asking out of curiosity 

You should be able to set white balance off any color if the color you set it off is what the camera is expecting to see. If the camera is expecting to see 18% gray and you use an 18% gray card, in the light consistent with the scene, then the white balance should be good. 

[evikne]

4 hours ago, Qwertynm said:

Thought white balance meant to balance off white. Grey would give too warm of a tone, no? I have no experience with grey/white cards so I‘m asking out of curiosity 

If you think gray looks warm, it might be because it contained some yellow. True gray contains no other colors.

When white balancing, the value of gray doesn't really matter (18% is just a standard for setting exposure). The only thing that matters is that it is 100% color neutral, i.e. all RGB values are equal. You can't use 100% white or black, as this contains no color values, but really everything in between.

Edited January 19, 2024 by evikne

[David Wien]

I think people are being far too scientific about this: we are not taking photos in a laboratory!

I have a grey card, but I have on more than one occasion used my white shirt or a clean white linen handkerchief when under strange lighting. This was before I had any processing software that allowed me to adjust the colour tmperature subsequently. It worked quite acceptably. One does what one can.

In the last ten years I have rarely needed to use anything other than the AWB setting of the camera. If one shoots raw, any colour imbalance one is likely to encounter can be corrected in processing: the exception is when there is more than one light source of different colour temperatures -- then good luck!

David

[evikne]

Just to clear up some common misconceptions (and because I think this is a fun topic).

White balance cards and gray cards are actually two different things:

• A white balance card is made to set white balance and should be 100% color neutral, but can in theory have any grayscale value.
• A gray card is made to set exposure and should be exactly 18% gray, but can in theory have any color.

However, in practice, most white balance cards are also about 18% gray, and most gray cards are color neutral.

Therefore, they can pretty much be used interchangeably and no one really cares. 😉

[Qwertynm]

Thank you @evikne.  It’s always good to learn new things even if they don’t apply to my photography 

[IkarusJohn]

The Auto White Balance is sufficiently good on my M10-D and my X2d, I don’t bother setting white balance any more.

[Advertisement]

Hallo,

Look here: Leica Q

[david strachan]

I agree John and David

I rarely have to alter my auto white balance...but I don't take pictures in mixed stage lighting, or under funny spot lights.

I might change spot colouring  but global light colour changes are very rarely needed.

Modern cameras a pretty good at auto everything really.

[evikne]

The difference of using a white balance reference compared to AWB is often warmer, more pleasing and more natural colors. Very nice for portraits. But you usually don't notice it until you get the chance to compare.