What's It Called 'N Where Can I Get One?

08/10/2006 03:58:44 PM · #1

Hello Good People!

So, I'm looking for this chart, not sure what it's called, but it has grayscale boxes on it (white, gray & black) to adjust the color & levels on a picture correctly if the desired lighting cannot be achieved pre-processing.

Anyone know where I can download & print one online? Can you post a linky?

Thanks is advance!
PEace
Rooster

08/10/2006 04:09:35 PM · #2

oh, yeah, it's called a gray card, yeah? I need one with white & black on it too. One that I can print off my printer. Anyones gots a linky for N ONLINE SOURCE?

rex

Canon PowerShot SD780

08/10/2006 04:17:01 PM · #3

//www.google.com/search?hl=en&lr=&q=%22gray+card%22&btnG=Search

What if your printer is off calibration before you print this?

I would suggest buying one.

Here

Message edited by author 2006-08-10 16:17:57.

08/10/2006 04:32:40 PM · #4

yeah, I would buy one too. in fact I think i have one hiding somewhere in mi casa but I really need one 2day. My sis got a art showing & I have to shoot some of her work later 2day.

Thanks for the link Rex!

edit: curses! I did a google search & didnt find diddily... :(

Message edited by author 2006-08-10 16:33:44.

sammigurl

Canon EF-S 18-55mm f/3.5-5.6 USM

08/10/2006 04:42:46 PM · #5

Or you could use the little eyedroppers in the Levels dialogue box in Photoshop, right?

08/10/2006 04:45:53 PM · #6

Originally posted by sammigurl:

Or you could use the little eyedroppers in the Levels dialogue box in Photoshop, right?

Yeah I want to but it would be more accurate if I had the actual shades (white, gray & black) somewhere in the shot & then use the droppers to get it just right, see.

Ok, I have to go the west 34th street to the gallery & lucky louie, B&H Photo is on west 33rd. NYC RULES!

Sammigurl, I could post some before & after shots to show you what I mean if you;re interested. PM me of post here.

peace!

DjFenzl

08/10/2006 04:46:16 PM · #7

I read on Luminous Landscape the other day that gray cards do not work well with digital. Here's an exerpt:

Some people think of digital imaging as solid state film. This isn't the case. The following explanation by Bruce Lindbloom may help you understand what's going on with the above technique...

For film based photography, the highlight end of the scale is compressed by the shoulder portion of the D/log E curve. So as brighter and brighter objects are photographed, the highlight detail gets gradually compressed more and more until eventually the film saturates. But up until that point, the highlight compression progresses in a gradual fashion.

Solid state sensors in digital cameras behave very differently. As light falls on a sensor, a charge either accumulates or dissipates (depending on the sensor technology). Its response is well behaved right up until the point of saturation, at which time it abruptly stops. There is no forgiveness by gradually backing off, as was the case with film.

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.

sammigurl

Canon EF-S 18-55mm f/3.5-5.6 USM

08/10/2006 04:51:13 PM · #8

Originally posted by Rooster:

Originally posted by sammigurl:
Or you could use the little eyedroppers in the Levels dialogue box in Photoshop, right?

Yeah I want to but it would be more accurate if I had the actual shades (white, gray & black) somewhere in the shot & then use the droppers to get it just right, see.

Ok, I have to go the west 34th street to the gallery & lucky louie, B&H Photo is on west 33rd. NYC RULES!

Sammigurl, I could post some before & after shots to show you what I mean if you;re interested. PM me of post here.

peace!

That would be great.

But isn't putting that card in the frame taking up space in your photo?

kirbic

Canon EOS R5

Canon RF 24-70mm f/2.8 L IS

08/10/2006 04:51:56 PM · #9

Purely for exposure, yes, setting up with an 18% gray card for digital may not be the best approach. It's still of great value, however, in getting color balance correct. It gives a neutral gray reference so that the tonal curve may be compensated accurately.

leaf

Canon EF 24-70mm f/2.8L USM

08/10/2006 04:53:19 PM · #10

depending on what you want to do.

If you are trying to set white balance, a grey card will work just fine... and it will be the middle grey you want to measure, not the white.

DjFenzl

08/10/2006 05:01:27 PM · #11

really? Most software I have to correct color cast has me set the white point - not the grey point. does grey really work better than white when adjusting the color?

I'm asking because I don't know, i certainly am no expert on it nor have I ever played one on TV. I was an extra in Beverly Hills Cop III though... but I digress...

Message edited by author 2006-08-10 17:01:56.

sammigurl

Canon EF-S 18-55mm f/3.5-5.6 USM

08/10/2006 05:03:47 PM · #12

Photoshop has one for a white, gray, and black.

But that's for lighting. For color balance, it's called a white point, but basically any area you want with no saturation will work.

rami

Canon EOS-350D Rebel XT

Canon EF 50mm f/1.8 II

08/10/2006 05:12:20 PM · #13

is that the one you use to obtain the correct WHITE BALANCE.. ?