Question about white balance

[phix95]

I've read that for digital cameras you should expose for the highlights b/c shadows are easier to get detail from in an editor (photoshop), whereas if highlights are blown out, the detail is lost;
however,
I have also read that, even for digital, to expose for 18% grey (like film). So which is it to get the best exposure?
If it IS grey, you should always have a grey card with you yes? And if you do, in the sun won't the grey card look lighter? What light situation is the grey card "correct"?

Thanks

ps. I have a canon powershot a590

 

[fiveoboy01]

Exposure and white balance(color temperature) aren't the same thing.

You are correct that blown highlights are mostly impossible to correct because they contain no data.

An 18% gray card is used to set preset white balance in your camera, when either auto white balance or one of the preset white balance settings in your camera can't get it right. One example would be indoors, with several different types of light(flourescent and incandescent) and sunlight coming in through skylights or a window.

 

[EhJsNe]

ARgg.... Yes, generally it is easier to fix lighten shadows with detail than it is to darken highlights and get detail. However, it is possible for you to "blow out" the shadows (that doesnt seem like itsthe right word...but its the same thing as blowing out the highlights, you get no detail whatsoever) and if you try to lighten a "blown out" shadow, itll look like crap. Lots worse than a blown out highlight.

If you expose for an 18% grey card, 99.99% of your pictures will come out fine. That .1% of messed up exposures would most likely be human error or a complex scene (such as a bright sunny day with clouds, and dark rocks at the bottom, or a sunset, where what a "perfect exposure" would look not all to great, but thats what HDR is for tho! )
The greay card might look lighter in the sun....but so does everything else thats in the sun...so the perfect exposure of the grey card will be a perfect exposure of everything else!

 

[Big Mike]

Expose Right

 

[KmH]

Shadows can be 'blown' too, though they are then called 'blocked'. If the shadows are blocked they fail to retain any detail, like blown highlights, and cannot be recovered.

 

[jnm]

Expose Right

that was an interesting read. ive never used CameraRAW, would LightRoom allow you to do the same thing he suggests using CameraRaw for?

 

[robertwsimpson]

Expose Right

wow, I never thought of it that way before. I've got some spearminting to do now!

 

[BaileyAllison]

Expose Right

Wow, very interesting read. Thanks for sharing!