Luckylove
03-06-2007, 07:41 AM
Hey Jackie,
So I am reading this book I told you I bought. I was wondering, is there a hardfast rule on apertures? The author keeps referencing things like "I set the aperture to f/5.6 because she's wearing white". I understand that lower lighting means higher apertures. Just wondering if there is a "cheat sheet" of sorts that most photographers use.
Also, I am confused about shutter speeds. Is it correct that you use a faster shutter speed if the subject is moving? He didn't really go into shutter speed too much.
Sorry if these are lame questions but I appreciate the help!
Kathleen
a faster shutter speed is used when someone is moving, a slower shutter speed will give you a "blur" when they move.
As far as aperatures... For starters, know that a "higher aperature" is a "lower number.
So when you "bump up" your aperature, you're going Towards 1. Bumping it down, you are giong towards a higher number (say 10). Another term you'll hear is a "wide aperature".. which is a high ap/low number (1.8ish)
The wider ap allows in more light. A lower ap (like 5.6) lets in very minimal light. To be able to use such a low ap, you REALLY need to have a TON of available light, or set your ISO and SS to compensate.
There are really no hard-fast rules about anything in photography. That's why it's so confusing.. there is no magic bullet. Every single setting to choose will vary based on the smalles thing (which angle the light is coming from, if the sun is behind a cloud and then a moment later is out from behind the cloud.
A lot of it is trial and error.
I rarely set my ap any lower than a 3.0... my 2 main lenes go up to 1.8, and one goes up to 2.8, so i pretty much go with 2.8 on both (most prime lenses work best at one stop from their widest ap) just b/c most typicaly I don't have the light to allow for it, but also b/c I'm more inclined to change my shutter speed.
Here's why: ISO is what adjusts how much light is anticipated by your camera - in all reality, aside from teh lighting, it doesn't affect anything about your image.
shutter speed will change how much light is let in also. A faster shutter speed doesn't allow in as much light as a lower shutter speed (never go below 120 if hand holding/not using tripod.) BUT it can also affect your image in how "sharp" it will be. If someone is moving, a 120 shutter speed may show some shake to the image, and won't be in perfect focus.
aperature affects how much light is let in also, BUT it also affects your depth of your image. A 1.8 has a very shallow depht of field, a 5.6 has a VERY wide depth of field. I prefer narrower depth of field in ALL my photos, so i typically set my aperature first based on what i want, and then I adjust my shutter speed per image. Sometimes I'll have to adjust the ap, if there is too much light, or not enough, or whatever... but typically i leave it around the same numbers b/c that depth of field is important to my style of photography.
hth