camera focus

[Clip]

anyone here knowledgeable on the camera f-stops and apertures, and how they affect the focus of the picture? i've searched online but need a simpler explanation.

thanks,
-clip

 

[theKnifeArtist]

with apertures its how much the shutter opens up and how thats how much information(what your taking a picture of) your letting in. its related to F-stop..thats just how they mark it. less aperature means you let less info in, which gives you a less juicy picture but a good chance not to blur the picture. When you got allot of aperature, which is a smaller F-stop number, the thing opens up big time and you get a niiice picture with allota sweet lighting, but a very easy chance to blur the picture. so get an tripod.

 

[Clip]

beaut, Knife. thanks for the tips.

in my old canon ae-1 manual they gave examples of a chess board, with the foremost piece in focus and the rest blurred. next example, the center of the pic was blurred and the rest was clear. any input on this? i can dig out the old manuals if need be.

 

[phoenix6]

Thats focus. I forgot all the techy crap names but you adjust it all with the lens. Dammit, Im forgetting all the stuff I learned, I used to work for an Ebay store (yes like the one in 40 yr old virgin) and I sold vintage and antique cameras ALL the time, for these 2 guys who were veterans, amazing stories. Anyways, so they kept bringing shit in and I had to describe them and learned alot, but now its late and Im blank...

 

[cwapface]

You can think of it like a cone. Say you focus on a chess piece and you have stuff in the foreground and stuff in the background. The crisp focus on the chess piece is like the point of the cone, and it grows larger as it nears the lens, so the closer it is to you, the more out of focus it gets. Same deal with behind the chess piece, think of another invisible cone growing larger as it moves away from the camera so the imaginary person standing behind the chess board is not as blurred as the mountains in the background.

The more open the aperture is (the smaller the f-stop number), the bigger the diameter of the cone you are working with. Stop the aperture down to f/22 and you are dealing with a very narrow cone. Well it made sense to me anyway lol.

 

[Facime]

The more open the aperture is (the smaller the f-stop number), the bigger the diameter of the cone you are working with. Stop the aperture down to f/22 and you are dealing with a very narrow cone. Well it made sense to me anyway lol.

actually thats backwards. The smaller the aperature (larger f-stop number), the larger the depth of field is, and vice versa.

When shooting say a landscape, where you have a subject in the foreground (lets say a flower up close) and you want to keep the remaining background in focus, you will want the lens opening as small as possible (therefore you need alot of light or high ASA or long shutter times to maintain exposure). Ansel Adams used to use a pinhole camera, where the opening of the lens was not much bigger than a needles width.

this link has a pretty simple explanation of depth of field: http://www.azuswebworks.com/photography/dof.html

 

[Clip]

depth of field, thats what i was trying to remember. thanks for the help, guys.

 

[NATAN666]

f-stop is the size of the camera's "pupil" if its a low number like 1.8 then its WIDE OPEN, and will give you a VERY shallow depth of field, meaning that only a small portion of the picture will be in focus.. the more you close the pupil (increase the number) the less light you let in, and the more area will be in focus.

in can affect focus in many ways other than depth of field. havign too large of an f stop (too small of a number) would mean that the photo may not be as crisp and clear, while too small (too large of a number) and the light will distort and be extremely unclear (over f22)

so basically try and keep your f-stop around f5.6 and maintain a good exposure to that and youll be set