18% gray card

true_one_picture

true_one_picture

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Phil
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I recently read in an article that you can not create a 18% gray card in photoshop.

Now if i take a white background layer, then create a new black filled layer on top and set opacity to 18% this produces a gray.
Understandably it wouldnt be perfect but as a alternative could this work???

Comments please! its one thats bugging me. :bang:

Phil
 
If your looking for something to use out and about I was once told by someone that the insides of Lowepro bags are 18% grey!

Not sure how true that is or even if it helps with what your doing but I ermember at the time thinking that it was useful to know.

Chris
 
I recently read that 18% grey is only for film cameras... and 13% grey is more in line with digitals. :shrug:

Is there one thing we could use to get our exposure and our whitebalance right?...something small.

Does an exposdisc only do the exposure?
 
Well its true about the 18% film and different for digital but thats where its more confussing...

I read Nikon use 12% as a standard but yet company's such as Fuji use 14% and other company's use even different values!?!

The ANSI standard is 12%, check this article out for more info...

http://www.bythom.com/graycards.htm

The reason why I was thinking is because it would mean all someone would have to do is check there manufactures spec and make one up in Photoshop, this would save buying different ones for different cameras.

Thanks for the response so far.

Phil
 
true_one_picture said:
I recently read in an article that you can not create a 18% gray card in photoshop.

Now if i take a white background layer, then create a new black filled layer on top and set opacity to 18% this produces a gray.
Understandably it wouldnt be perfect but as a alternative could this work???

Comments please! its one thats bugging me. :bang:

Phil
Click to expand...

true_one_picture said:
Well its true about the 18% film and different for digital but thats where its more confussing...

I read Nikon use 12% as a standard but yet company's such as Fuji use 14% and other company's use even different values!?!

The ANSI standard is 12%, check this article out for more info...

http://www.bythom.com/graycards.htm

The reason why I was thinking is because it would mean all someone would have to do is check there manufactures spec and make one up in Photoshop, this would save buying different ones for different cameras.

Thanks for the response so far.

Phil
Click to expand...

Why don't you do a test with an 18% and then a 12% then a 14% and so until you find which one works best for YOUR camera.

Please post results and share with TP like most of us would do. It's your baby now. :thumbs:

Oh, by the way it is GREY not GRAY.
 
tiler65 said:
Why don't you do a test with an 18% and then a 12% then a 14% and so until you find which one works best for YOUR camera.

Please post results and share with TP like most of us would do. It's your baby now. :thumbs:

Oh, by the way it is GREY not GRAY.
Click to expand...

Sorry didnt know there was a procedure I had to follow before I asked a question on TP, I will do a test but I had to ask the question first. The one thing with a test like this is without expensive equipment I would not be able to tell N. Gray by eye alone, also different % would just be the same as using different white balance settings.

As for the Gray or Grey topic I checked this and even in photoshop's FILL tool its spelling is Gray :rules: so thats how I spell it.

Phil
 
true_one_picture said:
Sorry didn't know there was a procedure I had to follow before I asked a question on TP, I will do a test but I had to ask the question first.

As for the Gray or Grey topic I checked this and even in photoshop's FILL tool its spelling is Gray :rules: so thats how I spell it.

Phil
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It's an Americanism.

There is not a procedure I was just asking you to do a test and post the results as there does not seem to be a definitive answer.
 
true_one_picture said:
Flash in the pan: great product but it kind of looses the point of the post

There are lots of gray card products out there but my point is could we make our own since different manufactures use different values as neutral gray.

Phil
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In theory, yes you could make your own,but how do you know that you have 18% gray/grey/grise or 12% or whatever? If you are printing it off from Photoshop is your monitor calibrated and do you know that your printer/ink/paper combo will give a true representation of the desired shade?

Too many variables for me. I'll stick to my Grey Kard (not litterally)
 
Flash In The Pan said:
In theory, yes you could make your own,but how do you know that you have 18% gray/Grey/grise or 12% or whatever? If you are printing it off from Photoshop is your monitor calibrated and do you know that your printer/ink/paper combo will give a true representation of the desired shade?

Too many variables for me. I'll stick to my Grey Kard (not litterally)
Click to expand...

Great point Flash, as I said earlier it was just a wounder and as I have read in many articles the different companies have different standards so whats to say any particular value is right for the camera your using.

I think the answer to it all is:
Yes its correct but only to a point because it would be hard to print the exact value especially since it working on such detailed values.

Phil
 
in sRGB and using windows standard 2.2 gamma then the RGB values for 18% grey are 117,117,117. Pop that into the colour picker and then print it out. Provided you know you're gonna get exactly that out of your printer you should be ok!
 
Janice said:
Does an exposdisc only do the exposure?
Click to expand...

Nope - it only 'does' the WB, and is easier than using a grey card as it removes another step in PP as well as avoiding issues of reflectance of the grey card

(Grey is English, Gray is yankie - these days either seems to be fine as we all know what you mean)

DD
 
true_one_picture said:
Great point Flash, as I said earlier it was just a wounder and as I have read in many articles the different companies have different standards so whats to say any particular value is right for the camera your using.
Click to expand...


You are quite right, Phil.There are so many variables that it's probably nigh on impossible to produce an exact grey that will suit every different camera/printer/monitor combination. The best advice is just to suck it and see*










* Disclaimer: do not suck any electrical items without first ensuring they are switched off and disconnected from from the mains
 
There was a link Marcel (I think) posted:

here


The whole thing is worth a read, however the last paragraph states:

Because of this difference, setting up the exposure using an 18% gray card (as is typically done with film) does not work so well with a digital camera. You will get better results if you set your exposure such that the whitest white in the scene comes close to, but not quite reaching, the full digital scale (255 for 8-bit capture, 65535 for 16-bit capture). Base the exposure on the highlight for a digital camera, and a mid-tone (e.g. 18% gray card) for a film camera.
Click to expand...

Makes sense to me.
 
It should get you close enough, almost any mid grey cards will also work, it's only for really critical work you actually need a neutral grey colour (no colour cast) the percentage isn't as critical as all makes of camera meter and exposure bias vary slightly anyway.
Wayne
 
DiddyDave said:
Nope - it only 'does' the WB, and is easier than using a grey card as it removes another step in PP as well as avoiding issues of reflectance of the grey card

(Grey is English, Gray is yankie - these days either seems to be fine as we all know what you mean)

DD
Click to expand...

TY :thumbs:
 
Meter off your palm and expose at +1 1/3 over the reading, or meter off a sheet of white paper and expose at +2. That should get you pretty close. Lowepro bag interiors are pretty spot on for middle grey, too.

If you shoot raw and want to expose to the right then spot meter off the brightest part of the scene for which you want to record detail - i.e. not specular highlights or illuminated light bulbs etc. - and expose at +3, which will put that brightest (important) part of the scene on the right hand edge of the histogram. Specular highlights and light sources will be blown, but who cares? Do you want to try to read the manufacturer branding or wattage on a light bulb?
 
Am I missing something here, notwithstanding the debate over 12%, 18%, use one, don’t use one, the thing I can’t get my head around is that anyone is prepared to pay £11.50 to Gray Kard for a piece of plastic. We get the same with a whole host of credit cards, store cards, advertising and merchandising cards all FREE. This just happens to be Grey so they charge £11.50... Yeah right!

I know its an old thread but I came upon it researching Grey Cards :-)
 
The main difference with a grey card that you purchase, and that has been manufactured with photography in mind, is that it will be guaranteed to be colour neutral, so can be used for setting WB as well as exposure.

Not sure you could say the same for any other sort of grey card.
 
Have I just wasted my money on an 18% grey card?
 
As I understand it the Grey card is for white balance setting.

I have both a exposdisc (clone) and the Digital Grey Kard, which are use to set a custom white balance in the camera.

If shooting under say Tungsten light, your exposure maybe perfect, but you'll need to set the colour temperature (white balance) if you want to avoid a colour cast to you image, is this not what a grey card is for.
 
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This may be wrong but the way i see it it doesnt matter if its perfectly 18% or whatever, All you have to do is get the exposure to your liking (via chimping/histogram etc) then meter off the surface of your choice, see where the needle sits and just keep it there as the light changes.

Would that not do?
 
I recently read in an article that you can not create a 18% gray card in photoshop.
Click to expand...

You can test my 18% gray card if you like.

I think 18% is the amount of reflected light which
is supposed to be reflected by an object of 50% gray.

Have I just wasted my money on an 18% grey card?
Click to expand...

I think the grey cards you can buy are more accurate.
 
The original grey cards reflected 18% and were used for exposure only, most of the newer cards can also be used for setting white balance as well, although from my experiences theres a lot of dispute on what 18% looks like, personally I have never seen 2 the same shade of grey.
To be used for colour there needs to be NO colour cast, printing it yourself may introduce a cast that will throw it off slightly.
 
true_one_picture said:
Sorry didnt know there was a procedure I had to follow before I asked a question on TP, I will do a test but I had to ask the question first. The one thing with a test like this is without expensive equipment I would not be able to tell N. Gray by eye alone, also different % would just be the same as using different white balance settings.

As for the Gray or Grey topic I checked this and even in photoshop's FILL tool its spelling is Gray :rules: so thats how I spell it.

Phil
Click to expand...

Just for the sake of correctness, and not being picky, in Photoshop after calling up the text tool and typing in the word GRAY, you go to Window, Character, you will notice that at the bottom left hand corner there is a drop down box which enables you to check English (American) or English (UK). If you set this to English UK and then run the Spell Checker it will inform you that gray should be grey. It all depends of course whether you are in America or UK. Hope this helps.
 
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