Grey Cards & White Balance

King_Boru

King_Boru

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Right, I promised myself for a while now that I would look into this with more detail. I am forever getting leaflets through the door from camera accessory vendors telling me how good they are. Tonight, I decided to sit down and have a look into it with more detail.

The two parties which I have been researching is Lastolite (the grey card) and ExpoDisc (white balance).

I'll start with the Lastolite grey card. I cant really tell how you are supposed to use this thing and have guessed at the following ways:

  1. Do you place the grey card in the frame with the subject and meter as you would normally ignoring the card using it for post process purposes? Then take your 'main' shot without the grey card in the frame and sync the information later?
  2. Do you take a spot reading from the 18% grey and shoot from there? Does this give you your perfect exposure? Once metered you simply put the thing away?

I see so many photographers using these cards and I have always turned a blind eye,... So please, can someone tell me its worth an investment.

Secondly the ExpoDisc. I have never really delved into the whole custom white balance scene until today. So I dug out a piece of white paper, set my white balance for each test scene and it was spot on every time. Compared to the usually used auto setting which is quite random it worked a treat. So my main question is, how exactly do you benefit from the Expodisc? As I understand you clip it to the front of your lens, point it at the light source and take a custom white balance shot using your cameras options and go from there. What about exposure, you obviously need to maintain good exposure for correct white balance. So how do you expose through the ExpoDisc?

To those who have used it, can you please try and sell it to me because I am thinking a polystyrene cup shoved onto the front of the lens would do the same thing for 2ç.

I feel left out not having a million and one bits and bobs in my camera bag,... :rules:

Your feedback is much appreciated.

Dan.
 
Lastolite grey card ... My understanding is that the modes of use are not quite as you suggest. You can take shots with and without it in the frame, and then use it to fix the white balance in post processing. Or you can meter off the card to determine the right manual exposure settings. (Make sure the card is in the same light as the subject, and that the meter isn't seeing anything else... Either fill the frame with the card, or spot meter from it.) But you shouldn't use the with-and-without method to fix the exposure in post processing, because if you've exposed the scene wrongly in the first place (e.g. blown highlights) it may not be fixable.

Expodisc ... My understanding is that it can't help you with exposure, but the use for setting a custom white balance is as you describe. The advantages of this device over a sheet of white paper or polystyrene cup are durability and whiteness - "white" paper could be any colour from yellowish to blueish.

But whether it's worth investing in these things is a personal opinion. I tend to believe these days that, whilst there is an exposure and a white balance that is technically correct for each shot, the best choice is often a matter of taste. (On the other hand, if I shot weddings, I would be quite interested in making sure that the dress really is white!)

I hope this helps.
 
If you want 99.999% accuracy then maybe you will do better by buying a purpose designed thingy. Personally, I am happy to set WB using a sheet of white paper, or even a white shirt or t-shirt, or white paint etc. within the scene. I know there is white and then there is "white" but I'm happy that my paper stock is close enough. If there is nothing like that within the scene, either by chance or on purpose, then I will tune WB by preset and then adjustment by eye (profiled monitor) until I get a pleasing image. I always shoot raw, so setting WB is something I do after shooting, rather than before.

Same thing with exposure. I find that same sheet of white A4, set to +2 stops on the camera's meter gives me a pretty good exposure. Alternatively, the palm of my hand and + 1 1/3 stops on the meter gets me there equally well. I struggle to see how I would be better served by an incident light meter or a purpose bought grey (exposure) card.

Have a look here - http://www.talkphotography.co.uk/forums/showthread.php?t=64540
 
I did think of getting an expodisc for weddings (I sometimes help as a second) but I've found from experience that shooting in RAW is my friend. One room I was shooting in last week varied hugely in white balance. The room lights themselves were orange (literally) but the room had huge bay windows so the closer to the window, the more the white balance changed.

I've found that outdoors, the 5D is very close to perfect for the white of a wedding dress (I always check by using the eyedropper tool in pp) Indoors it very much depends on the light source.

Practically I don't think I will be investing in one because it would be impossible to use in such varied and shifting conditions. I'd never get the shot. And it's better to get the shot and have to adjust the colour balance in pp than not get the shot at all.

Perhaps it would be more useful in other settings?
 
i recently purchased the lastolite grey card. I find it useful as its has a cross hair on the center and can focus on the grey card. no more switching to manual and back. I like doing macro work on flowers so making sure the shades are jsut right is always a good thing
 
I use the Expo and think it an invaluable tool as it means I don't have to think about WB at all, so PP for that is not required

Same as shooting in manual for Weddings, another thing to not think about 'correcting' in PP

Makes life easier/swifter on a time is money basis

I also know a tog who uses a grey card all the time by asking one of the Wedding party to hold it near the bride for a 'control' shot; but the Expo is quicker and more reliable than hoping a guest will help and has less impact on the flow of the proceedings

My 2p anyway

DD
 
how does the expodisc work?
 
33L said:
how does the expodisc work?
Click to expand...

Hold/attach to front of lens, point at light source (switch lens to manual focus to stop it hunting) any auto exposure setting will work too. ON my camera, I press and hold the WB button, which flashes when ready, then expose a shot and it says 'Good' meaning it's set

Takes about 10 secs in all and doesn't need doing again until something changes significantly

DD
 
thanks for that - seems like a good tool.
 
I can see why you would want to do that for a batch of shots DD, save on any pp work:thumbs:

The difficulty I would have had last weekend though was the huge bay windows mixed with the interior lights made it an ever shifting mix of lighting. No way could I have taken a reading for each shot. Perhaps I need to rethink using it for batches. Take one reading for all the outdoor group shots and i'll know I'm bang on and just forget the mixed lighting because they will all need looking at anyway!

Food for thought though, thanks. :thinking:
 
AliB said:
Take one reading for all the outdoor group shots and i'll know I'm bang on and just forget the mixed lighting because they will all need looking at anyway!
Click to expand...
Sounds good to me.
 
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