Pekka or ? Setting White Point

[John Vito]

Pekka-

I notice that one of the things that characterizes your photos is the vivid, natural colors. I know you use RAW format and frequently set the white point. I have been having some problems setting the white point, especially in cases where there is no white to use as a reference or in the case where there are several white objects in the photo but the objects are in different lighting conditions. Have you posted anything in the way of a tutorial on how you go about setting the white point? If not, can you give a brief explanation. I would like to know what software you use when converting. Also, I would like to know if there is a batch method. For example, I take three shots in the same lighting conditions and the second one happens to have a white object in it that I can use to set the white point-how can I use that same setting to process the other two.

Thanks for any info you or others can give.
JOHN

[mpkirby]

I can't answer the part about what pekka does, but if you use zoombrowser, you can ctrl-click the pictures you want to convert. THe first picture selected will be used to pick the white-point from. After you select convert to raw with user options (or whatever the name of the menu item is), it brings up the thumbnail of the first picture. You pick the white point, and it will convert the remaining images using the whitepoint of the first image.

A couple of points when using raw.

1) Remember the best way to get vibrant colors in your picture is to have good lighting with a good exposure. If the right light doesn't make it to the CCD, nothing in the Raw conversion is going to fix it.

2) You can select anything that is supposed to be neutral. Grey All the way from "white", to "black".

3) Selecting the white point is most useful when you have multiple types of light coming into a scene. For example, room lighting, window lighting, and flash. Here you may be forced to make a compromise. If you select a white point for the flash, the background looks like crap. If you select for the background, the people look green. Selecting the whitepoint by hand lets you pick something in the room that is a mix of lights.

4) You can carry around a grey card, and shoot a picture of it if you are going to be taking a whole series. Just make this the first thing you pick in zoombrowser when you convert raw to tif.

Mike

[Pekka]

mpkirby had good points there.

Something I do often when seeking white point: see where the strongest light is coming from, follow the path of the light and see where it hits something on the picture that shoud be neutral (shade of gray). As mpkirby said you should try to avoid having many different light sources, as it makes overall balance uneven.

And don't try to seek for "real" colors, try to get out colors which look good. Often reality is unimpressive - consider RAW export your darkroom where you try to get the best out of the shot.

[sjguenard]

Quick and dirty: point lens at most prominent light source (not the sun!) and follow directions in manual p. 64. Works under sodium, tungsten, flurescent.
I always carry a folded piece of white paper in pocket to "read" hard to get light by reflection. Say "shooting" little critters in pet store cages etc.

[transco]

For some reason I am unable to control which picture is used for setting the whitepoint when doing a batch convert by holding down the control key and selecting multiple CRW files. Someone wrote that it will use the first picture selected, but it doesn't work for me. I've tried resorting, renaming, renumbering, but Canon seems to have its own criteria for which CRW file it opens first. I'm using W2K.