Aperature photography/art/design

[Bubblegum Bandit]

Apeture: The apeture, or F-stop, is the size of the hole the light comes through in the lens. Bigger hole = more light. Apeture size is also measued as a fraction, F2.8 is actually 1/2.8. So F5.6 is a smaller hole then F2.8. It also affects what is called the depth of field. Basically, DOF(depth of field) is how much of the picture is in focus at once. Example: You focus on a person's face 2 feet in front of you. With a wide apeture, say 2.8, you may not be able you get the whole face in focus at once. The eyes are in focus, but the nose ia a little fuzzy. This would be because the depth of field is only a few inches(so anything more then a couple inches in front of, or behind the focus point will be out of focus). If you were to close the apeture a bit, down to F8 or so, suddenly the whole face can be in focus at once because the DOF would increase from a few inches to 6 or maybe 8. So you have to decide ... do you need DOF, or more light?

 

 

HTH

-George

<{POST_SNAPBACK}>

 

Ok, lets talk about aperature for a sec. The terminology confuses the hell out of me. So as you go up the line from F1 up to F22 the opening that allows light to go through gets smaller, correct? 1/1 > 1/22. So, then from my reading it tells me that going 1 F-stop larger gives you twice as much light. If I'm shooting in F5.6 and some says you should step up an F-stop, should I be moving to F4 or F8?

 

Here's my confusion, the way aperature is recorded/viewed on the camera lenses, in my head stepping up would be going from F5.6 to F8. But, if you think about it in terms of diameter of opening, stepping up would be going to F4 because the diameter of the lens is getting bigger.

 

Which rationale is "correct" in the photography world. It always confuses me.

[Scourge]

Alrighty .. here it goes.

 

Q. So as you go up the line from F1 up to F22 the opening that allows light to go through gets smaller, correct?

A. Correct

 

Q. If I'm shooting in F5.6 and some says you should step up an F-stop, should I be moving to F4 or F8?

A. Stopping Up would be opening the apeture up larger, so F4.

 

Here's my confusion, the way aperature is recorded/viewed on the camera lenses, in my head stepping up would be going from F5.6 to F8. But, if you think about it in terms of diameter of opening, stepping up would be going to F4 because the diameter of the lens is getting bigger.

 

Which rationale is "correct" in the photography world. It always confuses me.

 

Yeah, It took me a while to get my head around it too.

 

So, then from my reading it tells me that going 1 F-stop larger gives you twice as much light.

 

Now this is a tricky one. Yes, one stop higher will double the light.

BUT going from say f5.6 to f5 is not one stop as one might guess. The stops go F1.4, F2, F2.8, F4, F5.6, F8, F11, F11, F16, F22. Moving from one to another will double/halve the anout of light depending on which direction you are going. Now you're wondering "but my camera has more numbers in between those" lol, yeah, confusing eh? Most lenses will go in 1/3 stops. A 1/3 of a stop difference in exposure can greatly effect a picture. (Most camera's will have an exposure control in auto mode that will let you make 1/3 stop adjustments .... ).

 

And while I'm here and talking about stops and 1/3rd stops. Shutter speed stops. 1 second, 1/2 sec. 1/4 sec, 1/8 sec, 1/15 sec, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000. These are all the main stops. One stop between one and the next.

 

Shoot away if you have any more questions.

 

HTH

-George

[Bubblegum Bandit]

Yeah, I understand shutter speeds and 1/3 stops. Like I say, in practice I can set my camera to what I want using these. But when I start thinking about the terminology I start going round and round in my head over what is up and what is down as far as aperature goes. I just need to ingrane in my head that UP/DOWN refers to diameter of opening and I will be fine.

 

I struggled for a long time with ISO especially when I was shooting 35mm because you had to shoot a whole roll before you could change the ISO. With the purchase of my new camera I'm becoming accustomed to throwing the ISO in the mix of the equation. I still don't know the "exact" (I say that but in photography "exact" is in the eye of the beholder) situations to use 400 vs 200 etc.