white balance

Is there something that tells you how to set ? Going from " P " TO , AV or TV seems to erase what I set .
I shoot in Raw + jpg and when I adjust , the shot goes from blue-esh to yellow-est with none looking good .
A Mexican wedding would be a good example . from dark inside church to bright sunlight after mass to different lights at reception .
I want something that says - set this at this ? Asking too much ? Does the Sekonic 358 do white balance ?
Is there a good book on it , most have a page or 2 and move on .

I would suggest shooting a white balance target of one sort or another. I use a Lastolite White Balance target, shoot in the light you will use and either set it as your custom WB or correct from it in post. The Ed Pierce(?) target looks interesting too because it gives you white, grey, and black.

The L-358 will not do that. I'm not aware of anything that will tell you what to use and I don't know why your camera isn't holding when you switch modes. It should hold in the creative modes.

It might be but the pictures vary and I don't know if it's me moving around or camera - lens changing .
I tried a 16 % and an 18% gray cards but I got / get different readings without people and then with them .
I go into church , take a reading , go into hall and take a reading , outside church so I am ready but then when people show up everything is different .
Probably reflections and sun moving . The bride in white and groom in black doesn't help . Thanks for input .

You say you get different readings? On what are you getting different readings? If the camera is in AWB you will get a different reading every time you shoot. Not necessarily a correct reading, just a different reading.

The worst was outside . I took a reading and it said +1 then after mass / service with people outside it was "o" or OK . Outside WB set to sun , inside church Incand.
I take a reading in church with a few people and again when everybody's leaving one stop different then the bride and groom come back in for pictures with family / priest from 1/4 to 1/2 difference .
I have noticed that when the brides maids wear light pastels it isn't as bad as when they wear darker colors .
I found a manual on the l 358 Sekonic on line and it says it doesn't do white balance . You were right about that .
Sorry for being a pain-
I have read /looked up in the following books
Digital photography - sucks - I am great , see my pictures
Peterson's understanding shutter speed and understanding exposure both mainly 35 mm
Digital photography made easy lots of pictures - no before / after -
Blue crane DVD's 1 on XTI and 1 on EXII 580 - ok
A short course in Canon EOS XTI - 2 pages that don't help much .
Adobe camera raw for digital photography - Ron Sheppard - best book so far - still reading it .
I am begining to wonder if I am mixing apples and oranges expecting to find grapes - if that makes sense .

I think you are confusing white balance with exposure.

Shoot RAW, include something white in one frame for each time the light changes (white balance card or brides dress), use the white balance tool to fix it later.

I shoot raw + jpg . I'll try reading up on it some more .

White balance has to do with the color of the light, degrees Kelvin. Exposure is intensity of light.

Thanks , I thought it had to do with light temperature + f stop + speed and ISO . Well back to books .

More than you would ever be likely to need to know about color temperature can be found here:

http://en.wikipedia.or​g/wiki/Color_temperatu​re

The short version is that color temperature has to do with the color of light. It is called color temperature because the colors are based on what colors a theoretical "black body" would be at a given temperature measured in degrees Kelvin. The Kelvin temperature scale is essentially centigrade, but with a completely different starting point. Zero degrees centigrade is at the freezing point of water. Zero degrees kelvin is the point at which all molecular motion stops. So zero degrees centigrade is 273 degrees kelvin.

Now, as this theoretical black body warms up, it starts to glow. It's like a piece of steel - it starts glowing in the neighborhood of a dull red and the hotter it gets, the bluer it gets. The crazy thing about color temperatures is that the hotter the heat temperature of the black box, the cooler the color. That is because color is described by the emotional response it produces rather than heat of the theoretical black box. Blue is a cool color despite having a higher color temperature than red, which is a warm color.

In summary, color temperature is all about the color of light. It doesn't have anything to do with shutter speed, aperture, or ISO.

A footnote: I realize that I should say 273 kelvins rather than 273 degrees kelvin, but this is confusing enough and almost everyone in photography includes the degrees.

Second footnote: A black body is something that absorbs all the energy it receives. In black body radiation, the black body also radiates all the energy it receives. No real need to get into this just to understand color temperature.

Jim M wrote in post #6017724
...

A footnote: I realize that I should say 273 kelvins rather than 273 degrees kelvin, but this is confusing enough and almost everyone in photography includes the degrees.

...

I didn't know that! This is why I love the forums - there is always somebody around who can go the extra mile with an explanation. Thanks.

Now if I could just stop these references to Canadian Geese.

Titus213 wrote in post #6018071
...Now if I could just stop these references to Canadian Geese.

What? You mean they are not citizens of Canada?

Thanks again . It's starting to make more sense .