About Exposure Compensation :S

[Moni]

As I am new...to this media...I don't know much...besides...I've just bought a new Digital Canon PowerShot S400 only for personal use...but suddenly I was attracked by an exibition of photography...and want to learn it...after learning it...when I'll be expert I'll buy good one to shot good shots :)

Now can you give me some knowledge on Exposures???

When I'll go -ve and when +ve? And how it's related to light? When to use Shutter Speeds and when not?

[stopbath]

Reflected light meters only guage light as if all light was reflected off a medium grey object. Thus a photo of a white wall, black wall, and grey wall would all be the same resulting image (ignoring detail and such and assumin enough light was present to garner an image.)

Use the + ev to turn lighter shades lighter and - ev to turn darker shades darker. You need not exceed -2 or +2 usually. (1 ev change = 1 full stop change in shutter speed or aperture.)

Now, you need a few books on photography, lots of practice to learn from, and enjoy photography.

[Moni]

Thanks for your suggesion and reply :)

Hmm...I'm reading a book by Niall Benvie...it seems good :)

Here I've found something about selecting midtones...but I've got the idea clear :?

Can you explain a bit? :)

[stopbath]

Basically the photograph resolves into about 10 zones of brightness. From pure black to pure white. Generally all 'texture' in a photograph will resolve to levels 3 to 7. (2 ev below mid tone, and 2 ev above mid tone. Mid tone being level 5)

Your spot meter may say "What ever you're pointing to, use F 5.6 and 1/100 to make it a good mid tone." If you use those readings, you will get mid tone. A mid-toned white rose, a mid-toned red balloon, a mid-toned black stone... You'll need to add or minus exposure to get them how you want...

If you have a grey card, that is mid tone. Bang on zone 5 (well, production run may deviate a smidge, but generally, right on.) If you meter off a grey card you'll get a decent reading withouth any +- EV calculations... So you'll have a white rose instead of mid-tone...

The "average scene" renders about midtone as it's a big mix of high, mid and low tones...

What is the 'correct exposure'? Whatever you want to use! If you want a white rose to be black (due to silouette effect) fine! (-3 or -4) If you want it grey to add sombre feeling, sure (as is). If you want it white with detail, fine (+ 1 or maybe 2) and if you want it a big ball of white with no hint of what it truly is, then fine again (+3 or 4). Thats the art part!

Hope I didn't confuse you too much :)

Hmmm... Also, the actual meter reading value may change with the meter choice!

If you choose evaluated meter, the camera disects the entire scene and tries to do a best comparison to it's database of shots. This gives you a good and easy way to meter quickly for even some complex images. It's not fool proof though.
If you choose center weighted metering, the camera gives more value to the middle portion of the portrait. A back lit portrait will be affected a little by the back lighting.
If you choose spot meter, the camera will ONLY read the boxed or circled area. Even a brightly back lit subject won't get fooled. It's more work, but the results are more accurate.