A question about grey cards

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Of those, I'd go for the Opteka from Amazon. I'd say you only need an expensive one if you're doing colour-critical photography (say product photography).
 
If you also want to sort your colours out and you use a raw workflow through Lightroom or Photoshop, the Xrite colour checker passport is very good (if expensive). It also doubles as a grey card.
 
i use raw and have a calibrated monitor so should be ok without the xrite but thanks
 
I have never bothered with one, (except for fun) I set the balance during raw conversion.

A true representation is rarely the best choice.
 
I never bother either. just as well buy a 18% grey lens cloth, one less thing to carry around.
 
found some on 7dayshop's ebay site for £3.99

They'll do!
 
Terrywoodenpic said:
I have never bothered with one, (except for fun) I set the balance during raw conversion.

A true representation is rarely the best choice.
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I would disagree, whilst I use WB creatively in my landscapes in most other things an accurate white balance is important, imagine a wedding where the bride's skin was a sickly hue and her dress not the right white, or product photography explaining to the client why their products aren't the colour they are in real life.

If you've got an accurate white balance it gives you a baseline to work from, Colorchecker Passport improves on that by letting you warm it up or cool it down in measurable degrees.
 
I agree with you mark - thanks for your advice here and the other thread!
 
markmullen said:
I would disagree, whilst I use WB creatively in my landscapes in most other things an accurate white balance is important, imagine a wedding where the bride's skin was a sickly hue and her dress not the right white, or product photography explaining to the client why their products aren't the colour they are in real life.

If you've got an accurate white balance it gives you a baseline to work from, Colorchecker Passport improves on that by letting you warm it up or cool it down in measurable degrees.
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For product work I always used colour patches (and took samples of house colours)
You can also use a button sized grey spot and include it in the first shot at weddings (or a fashion shoot if they do not give you a material swatch.)

Both methods give equipment free (unbiased) standards.

I never had a client reject a shot on colour grounds in some 50 years.
 
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DTS said:
i use raw and have a calibrated monitor so should be ok without the xrite but thanks
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In which case, you don't understand what the Xrite does ;)

Basically, it takes what the camera captures as a set of colours, matches them to a known set and then creates the mapping between camera colour and actual colour. So, if the camera sees green as a slightly redder shade than it expects to, it will tweak the colour back out to the correct point.

If you think of a 3D shape being the colour space, with correct white balance being the z axis, the colour checker helps you get the x and y axes correct too. Take a look here: http://photo.andysheen.co.uk/technical/lightroom-raw-vs-dpp-raw-processing/ to see (the images are mostly rollovers so you can see the before/after of the application).

If you want accurate colours, you also need to calibrate the camera and the Xrite allows you to do this.
 
markmullen said:
Colorchecker Passport improves on that by letting you warm it up or cool it down in measurable degrees.
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No, it allows you to calibrate the response of the camera to known real world colour stimulii. It also gives calibrated offsets from the correct WB, but the main use is to enable you to get different cameras to produce the same colours of the same objects.
 
arad85 said:
No, it allows you to calibrate the response of the camera to known real world colour stimulii. It also gives calibrated offsets from the correct WB, but the main use is to enable you to get different cameras to produce the same colours of the same objects.
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I know, I've got one and use it, I was explaining that in addition to the standard grey card it includes patches to give a warmer and cooler balance.
 
I understand what your saying but my aim here is to remove the blue colour cast. I always play with the colours in post anyway and don't necessarily want the right colour when I'm doing sunset blurred water type landscape shot. What I'm looking for are nice dreamy sunset shots and once I've got the original image back on screen I can commence the post work I want to get the shot I was originally after.

Thank you for letting me know about the xrite however, as I do feel I could use it in other situations other than with this particular filter :)
 
Do you even need one? The custom WB setting on my D3 says to sample something white, not grey. Perhaps its just my camera, but I've never needed a grey card and I routinely take product shots for stock.
 
James J said:
Do you even need one? The custom WB setting on my D3 says to sample something white, not grey.
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Do you know how many shades of white there are?
 
DTS said:
I understand what your saying but my aim here is to remove the blue colour cast. I always play with the colours in post anyway and don't necessarily want the right colour when I'm doing sunset blurred water type landscape shot. What I'm looking for are nice dreamy sunset shots and once I've got the original image back on screen I can commence the post work I want to get the shot I was originally after.

Thank you for letting me know about the xrite however, as I do feel I could use it in other situations other than with this particular filter :)
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I would say that sunsets are one time you dont need accurate colours. You either warm or cool colours to your desired result. With a sunset you want the colour cast its the whole point.
 
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DTS said:
i use raw and have a calibrated monitor so should be ok without the xrite but thanks
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But it still relies on your ability to judge what is a neutral grey, no matter how accurate your monitor is. A decent grey card will be exactly grey, so you can actually look at the RGB values and make sure they are all equal when white balancing. Unless you are doing colour critical work though, I'd not get too stressed about it. Sometimes you WANT to change things from strictly accurate. Having an accurate monitor is more about confidence that what you see is actually exactly represented on the file data so it prints correctly. Everything else is personal taste.
 
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What I want is to use the grey card to remove the cast, as its completely blue. I will then play with the colour to get it the way I imagined in my head not necessarily the way it would be seen by you.
 
Surely one could just go into photoshop and open a layer and set the background to 50% grey and print a square of it? So long as you have the printer profile of your printer?
 
DTS said:
Surely one could just go into photoshop and open a layer and set the background to 50% grey and print a square of it? So long as you have the printer profile of your printer?
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Its 18% grey it if you are going to print something thats about 18% grey you are just as well just click the grey picker on something grey in the image. Which has always been accurate enough for me.
 
donutagain said:
about the same as there are grey ?
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Colour wise - yes. The point is pointing at "anything white" doesn't guarantee a neutral colour balance. Also, unless you are very careful, you can end up saturating one or more of the R, G or B channels leading to incorrect white balance setting. The reason a grey card is used is to ensure that you have a neutral R:G:B balance AND that you are far enough away from saturating the individual channels that you are able to set a sensible balance.
 
Thought it was 50% grey and 18% grey was actually its reflective properties?
 
me too as everything is advertised as 18% grey - i only stumbled on the above suggestion that its infact 50% and its reflective properties are 18% when researching grey cards for purchasing during this thread, il see if i can find it again....
 
A typical example is the Kodak R-27 set, which contains two 8x10" cards and one 4x5" card which have 18% reflectance across the visible spectrum
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Thats from wikipedia - although thats not where i originally read it
 
I knew the 18% referred to the reflective properties. I didn't think it was a specific colour of grey its just equal amounts of rgb make grey.
 
rjbell said:
Its 18% grey it if you are going to print something thats about 18% grey you are just as well just click the grey picker on something grey in the image. Which has always been accurate enough for me.
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I very often do that too.
It usually take a few attempts to get what looks right. But it is far easier than tugging colour curves around.
 
i see how that would be easy - but it can also be a real pain to find the right grey in the image, id rather take a second pic really quick highlight both in camera raw a click the WB picker on the greycard job done
 
rjbell said:
I knew the 18% referred to the reflective properties. I didn't think it was a specific colour of grey its just equal amounts of rgb make grey.
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There are 2 types of grey card.
  • One type is used for setting exposure. It is supposed to be '18% grey', but the colour neutrality is not critical.
  • The other type is used for setting white balance. Here the neutrality of the colour is a key feature, as is its ability to remain neutral in all different kinds of light. This sort does not need to be '18% grey'.

Of course, there's no reason you can't have a single grey card to fulfill both functions.
 
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