For the cost involved it's a usefull part of any kit even if it's only used every 6 months...
They can't be, as many photoshops no longer carry them due to a lack of demand...
It depends on what you consider worthwhile. If your camera shoots RAW and you dont mind sitting around the computer adjusting you pictures they are probably not worth it. But I think the goal is to get the picture as close to perfect the first time as possible but I dont use a gray card; but I do have one. I have found that the ExpoDisc is a much better option and is a lot more accurate for getting the white balance set correctly..
Now I am assuming your camera can adjust the white balance. As far as I know most point and shoot cameras it cannot be adjusted but I could be wrong. I would say it is a matter of preference but I do use my ExpoDisc all this time and feel my pictures have a better color accuracy when it is used..
The main reason for adjusting your white balance is due to changing lighting conditions. Indoor lighting is different it seems each time you enter a different room or as the light changes during the day. Also snow and sand can wreak havoc on a sensor and if you shoot snow it will come out looking gray but if you adjust your white balance first it will come out white as it should..
I hope this helps..
David Trinkle wrote: >.
The main reason for adjusting your white balance is due to changinglighting conditions. Indoor lighting is different it seems each timeyou enter a different room or as the light changes during the day.Also snow and sand can wreak havoc on a sensor and if you shoot snowit will come out looking gray but if you adjust your white balancefirst it will come out white as it should..
OK, you want to adjust the WHITE balance. Then, why use a "gray" card, why not use a "white" card (or just a piece of white cardboard or some white paper)?..
You won't need a gray card for a large percentage of your photos because the white balance settings in most digital cameras today are accurate enough without them. This is a subjective statement because many pros use gray cards for optimizing their color balance and exposures for work where accurate color is critical..
However, there are instances where your white balance setting is going to go all over the place and your camera won't be able to settle on a consistent setting. This is where having a known value such as a gray card is going to stop going all over the place and give you one correct reading. Getting a precise white balance is a one-two punch where you need a known value as a target..
There is a growing market for lots of types of gray cards these days; there are way more choices for gray cards today than there was in the days of just film..
Most amateurs or photo enthusiasts never use a gray card, and many don't even know what one is, let alone have a need for one. If you need accurate reproductions, chances are you know what a gray card is and how to properly use it.Pixel_CultHave FunJoin the CultDon't be a Dolt..
I am not going to get into an argument with you over the value of gray cards and when to use them obviously you have never used one or plan on using one and that is fine. I tried to answer his question with the best knowledge I have and my use of them. Do I have one yes have I used it yes but I dont anymore because the ExpoDisc works much better for me..
Now as to you question on a white piece of paper; you can certainly use one and that will be fine but the color accuracy will not be as good as a calibrated gray card. The difference in a gray card and a white piece of paper is a gray card is 18% gray and will reflect all colors equally. Go to your local office supply and look at the paper there are several shades of white. Obviously if I used your analogy I would be able to set the correct white balance using snow and that cant be done. Now your camera calls it the WB or white balance but technically you are adjusting the color temperature. Here is a good link on gray cards and white balance.http://www.photoxels.com/tutorial_white-balance.html.
The current batch of digital SLRs do a good job of guessing on white balance, but we need to remember it's only a guess. The light entering the lens of a camera has a mixture of colors - wavelengths - that depend both on the objects we are shooting (whether they are red, green, blue, yellow, etc.) and on the light that is illuminating them (whether it is reddish, greenish, etc.). Having a patch of known color, be it gray or white, within the field of view, helps solve this puzzle of two unknowns in cases where it matters. In truth, often you don't want truly neutral colors to come out as such in your shot, as in a picture at sunset with the warm oranges and reds illuminating the scene. Calibrating to a gray card for such shots will rob them of their glow and warmth. But in many cases, having a gray card somewhere in your shot - or at least in your first shot, so you can balance subsequent shots off of it - will help you find the proper color balance for your shot...
David Trinkle wrote:.
Also snow and sand can wreak havoc on a sensor and if you shoot snowit will come out looking gray but if you adjust your white balancefirst it will come out white as it should..
No. The reason that snow is captured as gray is because the camera "EXPOSES" it that way. It has NOTHING to do with white balance..
If you misadjust the white balance and then take a picture of snow, it will be rendered as colored, like yellow or blue..
Unless you get the snow or sand INSIDE the camera, the sensor will be fine. .
Charlie DavisNikon 5700, Sony R1, Nikon D300HomePage: http://www.1derful.infoBridge Blog: http://www.here-ugo.com/BridgeBlog/..
No. The reason that snow is captured as gray is because the camera"EXPOSES" it that way. It has NOTHING to do with white balance..
1. The camera sees a lot of light coming in from the snow..
2. The camera assumes that this light is from a subject that is "18% grey" (or whatever percentage of grey the vendor programmed into the camera)..
3. The camera assumes that there must be a LOT of light hitting the subject. It chooses / suggests one or more of (closing aperture, keeping the shutter open for less time, turning down the ISO) to get the "correct exposure". In fact, the amount of light hitting the snow is much less than the camera believes; the level of light hitting the camera sensor is only so high because the snow is so reflective..
4. The photographer accepts the camera's suggestion ("it must be right") and underexposes the picture. Voila, grey snow!..
I shoot a lot of sports for the newspaper using an older Nikon D2H and I shoot under a lot of different lighting conditions. I use my little pop-open grey card all the time..
Even when I'm shooting in my studio with my own camera and my AB lights, I'll usually take a shot with the card. It doesn't hurt, it doesn't take that long and you never know...It might come in handy to have that exposure with it..
Scott W. McClure.
'You only get one sunrise and one sunset a day and you only get so many days on the planet. A good photographer does the math and doesn't waste either.'... The Late Galen Rowell..
No they are not... at least not when you can pick up an expodisc!..
Even when shooting with my lowly Canon A520, I have sometimes resorted to setting the WB manually (yes, the A520 allows this). I've never used a gray card though, usually pointing at a white ceiling is close enough. I've done this when taking photos in my house where most of the lights are those new CFL bulbs. These seem to really confuse the auto white balance resulting in a sickly yellow-green color cast. I've also used the lining of my camera case - which happens to be a nice gray WB reference.WayneCan0n G-nine 0ly C-21oo/C-4ooo/..