Approve the Cookies
This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and our Privacy Policy.
OK
Index  •   • New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Guest
New posts  •   • RTAT  •   • 'Best of'  •   • Gallery  •   • Gear  •   • Reviews
Register to forums    Log in

 
FORUMS General Gear Talk Flash and Studio Lighting 
Thread started 03 Oct 2009 (Saturday) 21:52
Search threadPrev/next
sponsored links
(this ad will go away when you log in as a registered member)

Gray card? what are they used for?

 
Muskydave22
Goldmember
Avatar
1,716 posts
Joined Jan 2009
Location: Menomonee Falls, WI
     
Oct 03, 2009 21:52 |  #1

I have been reading a lot of posts around here and people advising to use gray cards to get white balance correct? what exactly is a gray card and how does one use one? A little confused, is this something you purchase?

dave


Facebook (external link)
Flickr (external link)

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)
jeromego
Goldmember
Avatar
3,906 posts
Gallery: 2 photos
Likes: 1
Joined Jun 2008
Location: Florida
     
Oct 03, 2009 22:51 |  #2

a gray card is 18% gray. Scroll down to the bottom and you'll find more topic about this.


Jerome
Gear List
Canon CPS Member
www.lightsandimages.co​m (external link)
facebook (external link)

  
  LOG IN TO REPLY
TMR ­ Design
Cream of the Crop
Avatar
23,883 posts
Likes: 10
Joined Feb 2006
Location: Huntington Station, NY
     
Oct 03, 2009 22:57 as a reply to  @ jeromego's post |  #3

A gray card is used to set a custom white balance. Any source used for white balance (gray card, WhiBal, ExpoDisc, etc.) is completely neutral in that it has even amounts of red, green and blue. If you were to look at an RGB histogram showing the spike you would have perfect alignment of all three channels. If white balance is not set correctly you'd see the individual channel spikes out of alignment.


Robert
RobertMitchellPhotogra​phy (external link)

  
  LOG IN TO REPLY
colormaniac
Goldmember
Avatar
2,004 posts
Likes: 1
Joined Apr 2009
Location: Indiana
     
Oct 04, 2009 00:26 as a reply to  @ TMR Design's post |  #4

I'm no expert, having just learned it. But I'm puzzled by your claim that after you read so much you still couldn't find the answer. Are you after some issue other than just how to use a gray card, or why people use a gray card?

If not, maybe you can go to Youtube and search for a video on how to use a gray card. There are plenty. PhotoVision has some, too. It may be easier to learn by video than by reading.



- Good info: "How to Get, Give, and Take Photographic Criticism (external link)"
Gear list | Smugmug (external link) | ModelMayhem (external link)

  
  LOG IN TO REPLY
Muskydave22
THREAD ­ STARTER
Goldmember
Avatar
1,716 posts
Joined Jan 2009
Location: Menomonee Falls, WI
     
Oct 04, 2009 00:33 |  #5

i guess my main reason what what makes a gray card gray... i figured that out. Also, do you always need to use one of these? why not just let camera settle on Auto WB? or shoot Raw and fix later?

dave


Facebook (external link)
Flickr (external link)

  
  LOG IN TO REPLY
ByTheBrooke
Member
Avatar
137 posts
Joined Oct 2008
Location: Florence, AL
     
Oct 04, 2009 01:13 |  #6

I suppose that's true, but isn't the goal to achieve perfection straight off the camera? To need no or little post processing? That's what has always been "beaten" into me.

I will admit that I'd heard about a gray card back when I started courses through NYIP about a year ago (which I never finished) but never knew what it was. Now I think I should learn to use it :)


Brooke
Gripped 7D, Sigma 30mm 1.4, Sigma 85mm 1.4, Canon 100 2.8mm Macro, etc etc.... I just love to shoot!

  
  LOG IN TO REPLY
alphonsis
Senior Member
386 posts
Joined Jun 2008
Location: Bay Area, California
     
Oct 04, 2009 03:01 |  #7

The one thing that confused me for a while is that there are two types of gray cards. One for exposure and one for white balance.

Walking into my local photography store and asking for a "gray card" got me a mix of both types.

unless of course, I'm still confused, in which case someone should correct me. ^_^


My flickr (external link)
Rebel XTi, BG-E3, 18-55 kit, 50 1.8, 70-200mm f/2.8 L IS, 28-135 IS, Tammy 17-50 2.8, 580EX II, LP120, 7MDH, 46" Softlighter II

  
  LOG IN TO REPLY
colormaniac
Goldmember
Avatar
2,004 posts
Likes: 1
Joined Apr 2009
Location: Indiana
     
Oct 04, 2009 11:10 as a reply to  @ alphonsis's post |  #8

In reply to some of the questions, as far as I know,

1. using a gray card can reliably determine the white balance. Checking it on the screen is not reliable.

2. but then, of course, it depends whether you need to get THE right white balance. (The right one isn't always the one that pleases your eyes most.) That's why some people think it's important and some people don't.

3. the same gray card can be used to set the white balance and brightness. At least, this is what I found many experts suppose in their discussion here, and I successfully do both of them with the same gray card.



- Good info: "How to Get, Give, and Take Photographic Criticism (external link)"
Gear list | Smugmug (external link) | ModelMayhem (external link)

  
  LOG IN TO REPLY
PhotosGuy
Moderator
Avatar
75,349 posts
Gallery: 8 photos
Likes: 2173
Joined Feb 2004
Location: Middle of Michigan
     
Oct 04, 2009 12:42 |  #9

Grey Card who uses one and which one ??


FrankC - 20D, RAW, Manual everything...
Classic Carz, Racing, Air Show, Flowers.
Find the light... A few Car Lighting Tips, and MOVE YOUR FEET!
Have you thought about making your own book? // Need an exposure crutch?
New Image Size Limits: Image must not exceed 1600 pixels on any side.

  
  LOG IN TO REPLY
wyofizz
Goldmember
Avatar
1,340 posts
Gallery: 9 photos
Likes: 7
Joined Oct 2007
Location: Wyoming
     
Oct 04, 2009 12:54 |  #10

Muskydave22 wrote in post #8756407 (external link)
i guess my main reason what what makes a gray card gray... i figured that out. Also, do you always need to use one of these? why not just let camera settle on Auto WB? or shoot Raw and fix later?

dave

I always use one when shooting indoors.
My experience is that AWB doesn't work that great inside.
Fix later: Sometimes easier said then done and achieve exact colors.
(However I'm no PS expert)

Dave


Dave - Fuzzy Hashing makes me itch.

  
  LOG IN TO REPLY
Wilt
Reader's Digest Condensed version of War and Peace [POTN Vol 1]
Avatar
40,239 posts
Gallery: 1 photo
Likes: 2037
Joined Aug 2005
Location: Belmont, CA
     
Oct 04, 2009 15:58 |  #11

1. Some gray cards are for setting WB only, as they are not 18% tonality and therefore not suitable for a reflected light reading for setting exposure.
2. Some 18% gray cards are for setting exposure only, as they are not neutral in R-G-B balance and therefore would lead to falsely balanced photos for WB
3. Some gray cards are tonally balanced (same value for R-G-B) and also 18% tonality, so can be used for both exposure and WB setting.
4. You can take a shot with a gray card filling the viewfinder, and set Custom WB in the camera to shoot photos with correct WB setting. This is particularly the better way when shooting in-camera JPG files only, or...
5. You can shoot a shot with gray card in the scene and later use that during PP to set the correct WB setting. This works fine when processing RAW files in RAW convertors, or shoot in camera WB photos (a superfluous activity if shooting RAW and using a RAW convertors with easy batch processing tools, but a reasonable technique to use with captured JPG)


You need to give me OK to edit your image and repost! Keep POTN alive and well with member support https://photography-on-the.net/forum/donate.p​hp
Canon dSLR system, Olympus OM 35mm system, Bronica ETRSi 645 system, Horseman LS 4x5 system, Metz flashes, Dynalite studio lighting, and too many accessories to mention

  
  LOG IN TO REPLY
sponsored links
(this ad will go away when you log in as a registered member)

1,125 views & 0 likes for this thread
Gray card? what are they used for?
FORUMS General Gear Talk Flash and Studio Lighting 
AAA
x 1600
y 1600

Jump to forum...   •  Rules   •  Index   •  New posts   •  RTAT   •  'Best of'   •  Gallery   •  Gear   •  Reviews   •  Member list   •  Polls   •  Image rules   •  Search   •  Password reset

Not a member yet?
Register to forums
Registered members may log in to forums and access all the features: full search, image upload, follow forums, own gear list and ratings, likes, more forums, private messaging, thread follow, notifications, own gallery, all settings, view hosted photos, own reviews, see more and do more... and all is free. Don't be a stranger - register now and start posting!


COOKIES DISCLAIMER: This website uses cookies to improve your user experience. By using this site, you agree to our use of cookies and to our privacy policy.
Privacy policy and cookie usage info.


POWERED BY AMASS forum software 2.1forum software
version 2.1 /
code and design
by Pekka Saarinen ©
for photography-on-the.net

Latest registered member is Bhalaje
554 guests, 258 members online
Simultaneous users record so far is 6430, that happened on Dec 03, 2017

Photography-on-the.net Digital Photography Forums is the website for photographers and all who love great photos, camera and post processing techniques, gear talk, discussion and sharing. Professionals, hobbyists, newbies and those who don't even own a camera -- all are welcome regardless of skill, favourite brand, gear, gender or age. Registering and usage is free.