Apeture/White Balance question

I will choose the white color instead. If still does not fit, then adjust it manually.

I am going to buy a gray card and take a snap shot, then I can use it as the benchmark under the same lighting condition

Frequently, I find that this problem occurs with mixed lighting and when I have taken a series of shots in similar circumstances. If so then the solution is simple -- search through the shots to find something with grey (or white if necessary). Once you have one such area of grey then use Aperture's White Balance to get a reading and use these readings on all the shots. After that you will need only fine tuning. And next time make sure you have one test shot with a grey card or paint in it.

A neutral section of the image has the R, G, and B channel values all the same. The number doesn't matter, so much as the agreement with each other.

But that's not what you want to aim for as you look for a neutral spot to colour correct, since aligning the channels is how that process works. That is, if you use the white balance tool to select a spot that's already neutral, you won't see any change in the image white balance. What you have to select is something you believe is supposed to be neutral, but may not currently be so.

Any color where the amount of 'red', 'green', and 'blue' are all equal will work -- including "white".

But you're not searching for color values where the R, G, & B values are equal... rather you're searching for colors you know are supposed to be equal -- yet are not. The white-balance will then adjust them based on how out-of-balance your selected color is to correct the color to be in-balance (and everything else in the image will be adjusted relative to that selected point.)

This just gets you a starting point -- you might need (or want) to tweak it off that starting point just a little. e.g. At a wedding with candles the images probably should appear just a touch to the warmer side -- a true & "perfect" balance that fails to represent that candles would have put a slight warm cast on the room would make the pictures appear "cold".

At the very least, make sure the color adjustment appears consistent from image to image.

Hi,
If I cant find a Neutral Grey in a photograph, I usually adjust the White Balance by eye, the results are quite pleasing and sometimes surprising. It depends how critical you want to be.

Gerry.......

I agree with Gerry, Colour is very subjective. The numbers allow you to ensure all images have a common WB datum point. The main thing to watch and be careful of is the Ambient Light when making adjustments. This applies to any not just WB. Allan

In Final Cut Pro you can just select a color that's supposed to be white and boom, there it is. Why can't Aperture do this? How often is a neutral grey in the shot? Choosing from whites to white balance makes sense and I'm ****** off at Aperture right now.

White balance is not important in that case. Aperture sets a white balance in much the same way as the camera in auto wb mode. Though it is not fixed as per a jpeg. WB does what it says on the tin. If you have no white items in the picture. There is not much point getting critical about it.
ask yourself is it important.

If you shoot with a light source of known temperature. Use the numbers in Apertures wb to set degrees kelvin.

You can can select a " colour " thats supposed to be white and very accurately.

The easy way is pull the slider until it looks white. So long as the walls and ambient light are not affecting your colour perception.

I can not understand why you are hacked off about it, Aperture is not the easiest thing in the world to understand and it could be better but, it is about as good as it gets.

128 is the mid Grey Tone. Allan