Gray Card Question

Why is the gray card used for?

what does it help set?

and how do you adjust with a gray card?

I don't wish to be mean, but have you heard of Google? A one second search found this link http://www.the-digital-picture.com/Reviews/Gr​ay-Card-Review.aspx which really explains it well and saves a lot of typing. Kudos to author.

I don't wish to be mean, but have you heard of Google? A one second search found this link http://www.the-digital-picture.com/R...rd-Review.aspx which really explains it well and saves a lot of typing. Kudos to author.7 Hours Ago 22:50

Appreciate you not being mean, I am fully aware of Google! I have always figured a forum as like this one was to talk and explain photography and display our work. If we used google everytime we have a question then we would not need a photography forum just a page to display our work. Sorry that you had to type an answer to my question. Thanks for the link btw.

Now now children!

You're right though, forums are a good place for sharing info and no matter how basic your question may seem, we were all beginners at some stage and all needed answers to questions that are seen by some as simple and seen here a thousand times. However, I would never be afraid to ask a question on these forums. Sure, I may search the forum first, but often I won't find the answer to a specific question so then I will ask.

So, back to the question, the grey card is a useful tool for getting your exposure and white balance sorted. I have never used one though so I'm not the best authority here on the subject, although the link above seems a good place to look for info.

Need an exposure crutch?
More on how the subject affects the exposure in Post # 47

mdaddyrabbit,,,,all camera exposure meters are calibrated to measure 18% reflectance grey...That is 18% of light is reflected 82% is absorbed..Grey cards do just that,,reflect 18% of the light..

Grey cards are useful when the lighting is a tad tricky like in situations where the subject is back lit..Take a meter reading off the grey card when placed near the subject..Use this exposure reading as a basis for your exposure..

Jurgen

Shoot the card and set the gray point in photoshop or Caputure 1 to establish colour balance for accurate colour rendition for commercial.

I believe (at least according to the link I posted) that the meters actually meter closer to 13% gray, but the principle is identical.

So if I am reading right gray cards are used for closeup, for landscape this would be an non issue?

mdaddyrabbit wrote in post #5330175
So if I am reading right gray cards are used for closeup, for landscape this would be an non issue?

Can be used in any lighting situation especially when the lighting is a bit tricky..

I use a grey card to set a custom white balance - mainly indoors (e.g. gymnasiums, school halls, etc), where the light is less than ideal and the preset white balance options don't really work. The grey card neutralises some of the colour tones you might otherwise get in your images

mdaddyrabbit wrote in post #5330175
So if I am reading right gray cards are used for closeup, for landscape this would be an non issue?

If the same light is falling on the grey card as the distant landscape then yes you can, but often the light falling on a distant hill or whatever could be slightly different (cloud cover etc.) - in this case best to spot meter off a neutral tone (grass or blue sky at 180 deg from the sun is usually pretty good)

Crossfire wrote in post #5331447
I use a grey card to set a custom white balance - mainly indoors (e.g. gymnasiums, school halls, etc), where the light is less than ideal and the preset white balance options don't really work. The grey card neutralises some of the colour tones you might otherwise get in your images

Can you ignore the grey card all together and shoot RAW and then post-process for white balance?

trickyricky wrote in post #5366813
Can you ignore the grey card all together and shoot RAW and then post-process for white balance?

Yes (for white balance, not for exposure use obviously) , but you may want one shot with a grey card or other known neutral reference for WB. For casual uses often a white object in the scene can be used as a reference point; for more precise work a true neutral such as a grey card is preferred. Many camera bag interiors are gray and make a decent substitute.

lungdoc wrote in post #5330059
I believe (at least according to the link I posted) that the meters actually meter closer to 13% gray, but the principle is identical.

A great traditional (film) technician, Ctein, can expound in great detail why it is true that meters actually are calibrated to 12% gray level.