greycard

[larsh]

Good morning, we try English again.

AP is only used once a year, so I forget all... And greycard is not found.

Please tell me how to change the whole image clicking the greycard in it; or another color.

Thanks, regards

lars

[Gabe]

Hi @larsh,

Affinity Photo does not have a gray-card function. The colour picker from White Balance works on White colours, not gray. 

Thanks,

Gabe. 

[toltec]

You can use the Develop Persona and the white balance tool.

That will work on whites or greys.

You can Shift click and add extra sample points to average out the reading.

 

You can also apply a White Balance Adjustment layer.

Layers > New Adjustment Layer > White Balance Adjustment

If you click on the Picker, like the Develop Persona you can click on whites or greys to balance the image and also Shift click to add multiple sample points.

 

It has to be white or grey, it won't work on colours !

[Gabe]

@toltec, our white balance is mainly designed to work on white, not gray. If used on gray, it generally over-adjusts the image ( if it's too warm, it will make it too cool, and vice-versa). From the help file:

Quote

• Picker—allows you to sample the image to set the white point on which the white balance will be calculated.

• In Develop Persona, a dedicated White Point Tool is used instead of the Picker. It offers the same sampling functionality as the Picker.

 

[toltec]

41 minutes ago, GabrielM said:

@toltec, our white balance is mainly designed to work on white, not gray. If used on gray, it generally over-adjusts the image ( if it's too warm, it will make it too cool, and vice-versa). From the help file:

 

Oh no, don't say that. !! 

I used it on about 100 photos that only had grey in them and I thought it did a really good job. A minor tweak and a Preset and it saved me loads of time.

I shall have to redo all those pictures now and stop recommending Photo to everybody 

 

[larsh]

Hi, thanks a lot, the way @toltec shows is ok for me to find a first change before fine tuning.

Gruss

lars

[firstdefence]

I always thought the 18% grey card was a myth and most camera's aren't actually set to 18% they are bias towards 12-14% ish anyway.

I use the threshold adjustment to find the hotspot.

[larsh]

Quote

 

Ja, the grey card is old stuff. In digital-cameras the white balance may be good, more or less (as the grey card with real 18% or 16% or whatever). You know colors change with different light, flash, aperture... up to print colors (better than I do I think).

Importend is to have a part in the motiv with three equal RGB values, grey to white, for the first step in image editing.

My problem is to make pictures of art, sculptures and paintings of importend artists. The paintings hang at the walls, they shall not simple be reproduced. And it shall be done in a flat, some walls are white, some colered (lilac), in rooms with big windows and some without windows, lightened bei doors of the other rooms. The plan is to take one flash with softbox and little more power as the normal light as I did it in some big rooms of exhibitions to show the normal situation (using film 6 x 6 years ago; you see my digital training now); for some special situations may be added by little slaves (I love fluorescent tubes, but in this flat are none of them).

So there must be noticed some values of colors. First there shall be included a color card and a gray card in the motiv, second the same without them. Third I will use some apps to find the values RGB and so on of the walls.

I do not know the designer of the catalog now. I think the best is to give the origin JPG and RAW to her and a selfmade JPG edited (and hope the best; the painters are dead, this profession never seems to unterstand that color is like some liquid and can look different as on their easels).

What is today the way to communitate with designers? (It is not necessary to make an art board)

regards

lars

 

[R C-R]

48 minutes ago, firstdefence said:

I always thought the 18% grey card was a myth and most camera's aren't actually set to 18% they are bias towards 12-14% ish anyway.

As I understand it (which could be totally wrong), the problem with using grey cards is unless they are lit with the same color of light as the rest of the shot, using one as a reference won't work very well. So if different parts of the shot are lit by a mixture of different light sources, or it isn't practical to place the grey card where it would be lit by the same light that the camera sees (like in an outdoor shot of distant scenery) then you can't trust sampling from the grey card to be very accurate.

[firstdefence]

12 minutes ago, R C-R said:

As I understand it (which could be totally wrong), the problem with using grey cards is unless they are lit with the same color of light as the rest of the shot, using one as a reference won't work very well. So if different parts of the shot are lit by a mixture of different light sources, or it isn't practical to place the grey card where it would be lit by the same light that the camera sees (like in an outdoor shot of distant scenery) then you can't trust sampling from the grey card to be very accurate.

That's pretty much as I understand it, So at best it's a ball-park guide.

[larsh]

The grey card shall reflect 18% oft the upcomming light back to the camera. That was found (may be by Ansel Adams) as "normal" in a normal landscape. So it became the reference for the lightmeter. If the landscape or the motiv is not normal, as snow, dessert, sea or carbon, one has to correct it by hand, in earlier times.

There are two ways to use greycards. 1. One put it into the motiv only for checking the value of the aparture or speed with the lightmeter to give it to the camera, then take it away and make the image. The lightmeter only may "see" the greycard, nothing else of the motiv. It must stay in the correct angles, on the right place of the motiv...

What I asked for is 2. to put it in the motiv and make the image with it and another one without it, if it is necessary to use all the area of the film/ chip. Otherwise, may be making a reproduction of a painting one put the greycard and/ or a colorcard beside the painting (museums did it this way). Then the theory (!) said, click into the image of the card (greypoint) while editing the image and all color is fine.

[larsh]

Hi, I made a test. Two identical cameras E1, same lens 55 - 200 > same color card to RAF. You have to know, that my cameras are setted NOT to make full contrast.

First row: camera 1 in AP nothing done; second row camera 2; third row camera 2 in AP with auto contrast. Pipette 65 x 65 px

Red: 136, 77, 70   Green: 78, 109, 78   Blue: 73, 73, 114   White: 161, 160, 160   Black: 55, 53, 52   big Grey: 79, 79, 75

         140, 80, 72                81, 111, 81             79, 77, 118               166, 164, 166               57, 55, 54                   82, 81, 78

         205, 95, 82                97, 152, 96             93, 90, 165                251, 248, 250               54, 50, 47                  97, 95, 91

EDIT: two rows more; the origin cards analysed with two app android, first: Color Grab, second: Colorimeter, 5150 K Color Temp Meter

         255, 108, 100           51, 210, 146          110, 134, 240            255, 254, 254               59, 47, 45                 143, 145, 141

         247, 112, 106           39, 201, 154          102, 124, 210            243, 253, 254               62, 54, 52                   95, 98, 91

What ever the card-makers think about, the correct values RGB are different.

Nice day

lars

[firstdefence]

12 hours ago, larsh said:

The grey card shall reflect 18% oft the upcomming light back to the camera. That was found (may be by Ansel Adams) as "normal" in a normal landscape. So it became the reference for the lightmeter. If the landscape or the motiv is not normal, as snow, dessert, sea or carbon, one has to correct it by hand, in earlier times.

There are two ways to use greycards. 1. One put it into the motiv only for checking the value of the aparture or speed with the lightmeter to give it to the camera, then take it away and make the image. The lightmeter only may "see" the greycard, nothing else of the motiv. It must stay in the correct angles, on the right place of the motiv...

What I asked for is 2. to put it in the motiv and make the image with it and another one without it, if it is necessary to use all the area of the film/ chip. Otherwise, may be making a reproduction of a painting one put the greycard and/ or a colorcard beside the painting (museums did it this way). Then the theory (!) said, click into the image of the card (greypoint) while editing the image and all color is fine.

From what I have read, it was Kodak that effectively cocked it up in the 1970's and omitted the info that "the camera should be opened half a stop when using their grey card" bringing it more in line with the 12-14% so from then on photographers were actually using the grey card incorrectly informed, later on Kodak put the "open half a stop" info back into their instructions but I doubt people actually read the instructions and just start to take a reading from an 18% card and that's it.

The highlighted info was originally omitted: http://www.silverbird24.com/shop/media/files_public/trwtjbbcr/1903061.pdf which is a 2007 instruction manual, the info was put back in 2006 or thereabouts.

[R C-R]

Regardless of the omissions Kodak made in its manual, it does make it clear that grey cards are intended as an aid for setting the exposure of a photo, rather than anything to do with its color balance.

[lepr]

.

[R C-R]

11 minutes ago, owenr said:

Nevertheless,  a grey card is extremely useful for removing colour cast from photographs.

Sure, as long as all the precautions mentioned in the manual @firstdefence posted are observed when the photo was taken, like no nearby brightly colored objects reflecting light onto it or if it is not oriented properly.

[larsh]

Hi, in this image there is only used: white balance, +3 says AP. Then the messure is in the middle of the grey card. 72. 70, 72 is ok. That´s why I use the card. The angle is not really ok, but the flash would otherwise disturbe. It is a part, 100%. My system is not very good calibrated.

Regards

lars

[firstdefence]

But depending upon the ICC profile applied to the image the grey would read differently, I'm not sure R:72  G:70  B:72 is the correct reading if the image is exposed correctly I would expect it to be more than that. So an approximate reading of R:128  G:128  B:128 or a bit higher depending on the ICC profile used on the image.

That image looks dull, dark and out of focus to me.

[larsh]

Hi, you are right in all, I did not look at this and sent the wrong JPG. Only want to show, that it generally works with whitebalance to get grey: x, x, x. To get 128, 128, 128 in an image (!) the card must be lightened perfect, I think. It shall be neutral, that´s it. But the colors, as you see above in my rows, say: several ways give nearly the same values (some difference make the smartphone and the light). But in this card colors are all wrong. I will try a tiffen card next. It makes no sense to give a color card into the motiv of a painting, if the printer has not the same color values, isn´t? In former times in museums here they had a Kodak card to make the "Ektachromes" from paintings, as it is called till today. 

regards

lars

[larsh]

Now there comes Tiffen, one of two cards, they say this follows Kodak. It is the wide zoom with 55 mm with flash now (not 18 as before) and shown in 100%. The card stands in the images center.

And it is from the JPG, not the RAF. Shown is the grey circle field between white and black, the same as the background: nearly RGB 128!

Another question, my eyes are not so good: is it true, that a RAW/ RAF which is direct developed without any editing is not so sharp and light as the JPG?  MUST a RAF be edited to use before developed?

The colors of card two are very different as on the first cards I showed above. It makes no sense, I beleave now, to check the colors if the card lies not beside the printers computer. And the Tiffen is well known (in museums). The neutral grey is the main point. The JPG below is not edited, it is the image from the camera, but I set the dark and light in the camera to zero now (not both -1 to make the contrast later in the computer as it was set before).

Thanks (it is 20 years ago that I worked with paintings and a big flash)

lars