[noob] Aperture & focus

[dmunsie]

For some reason this really helped things click for me, so I thought I would pass it on for other noobs. I always thought if you changed aperture you had to refocus, but that's not true. Once you focus you can freely change aperture to see how it affects your photo. The best thing to do is to simply focus on a subject and then take a shot for each aperture your lens is capable of and then compare the results.

 

[MK3Brent]

Ever wonder what those numbers are on the focusing ring?

 

[SCraig]

It depends on which way you change your aperture. If you go to a wide aperture (i.e. f/2.8) from a narrow aperture (i.e. f/16) then you will have less depth of field. Not refocusing can put the point of focus outside the range of acceptable sharpness.

 

[KmH]

As long as you use the same point of focus and don't change the point of focus distance, yes, you can vary the lens aperture and see how the depth-of-field changes.

Note that the DoF changes both in front of and behind the point of focus.

 

[480sparky]

For some reason this really helped things click for me, so I thought I would pass it on for other noobs. I always thought if you changed aperture you had to refocus, but that's not true. Once you focus you can freely change aperture to see how it affects your photo. The best thing to do is to simply focus on a subject and then take a shot for each aperture your lens is capable of and then compare the results.

You can also take one aperture and see how changing the focus point affects your images as well.

 

[dmunsie]

As long as you use the same point of focus and don't change the point of focus distance, yes, you can vary the lens aperture and see how the depth-of-field changes.

Note that the DoF changes both in front of and behind the point of focus.

Exactly. I'm taking a few camera classes just to reinforce my personal findings and this was one of the first things we discussed.

 

[Damon]

Sorry folks. Another newby here with probably a dumb question. I have a Nikon D50 with a quantaray AF LD 55-200mm lens which says that it has an F stop range of 4 to 5.6 range. I have taken a basic beginners photography class so I'm not a complete moron in terms of basic vocabulary and what the basic terms mean so with that it mind here comes my dumb question. If my aperture range for this particular lens is 4 to 5.6 then why does (under certain shooting conditions) my display tell me my f stop is at 32 or higher when making adjustments? I most always shoot pictures in manuel mode so I am adjusting my shutter speed and f stop values picture to picture.

 

[Low_Sky]

The range of F stops on your lens are the maximum apertures. At 55mm, f/4 is your maximum aperture. At 200mm, f/5.6 is your maximum aperture. At focal lengths in between, the aperture will fall between those two value. From those maximum apertures, you can always go smaller from there.

 

[Damon]

I understand what you said about the maximum aperture at 55mm and 200mm but i'm reffering to the values the lense is going to "outside" the range of f/4 to f/5.6 which is noted on the lense itself. I was playing around last night trying to take a picture of my little boy in low light setting and the I guess the conditions where outside the capabilties of my camera however, in trying to adjust, I noticed my f stop value went up to f/32. Not f/3.2. 32. Im wondering why it went that high when the lense said it's range is f/4 to f/5.6.

 

[SCraig]

I understand what you said about the maximum aperture at 55mm and 200mm but i'm reffering to the values the lense is going to "outside" the range of f/4 to f/5.6 which is noted on the lense itself. I was playing around last night trying to take a picture of my little boy in low light setting and the I guess the conditions where outside the capabilties of my camera however, in trying to adjust, I noticed my f stop value went up to f/32. Not f/3.2. 32. Im wondering why it went that high when the lense said it's range is f/4 to f/5.6.

You're missing the point. The MAXIMUM aperture is the f-stop value of the lens when the aperture is wide open, and that is only one end of the range. The MINIMUM aperture is probably f/22 or f/32 or something along those lines. At 55mm your apertures will range from f/4 wide open to f/32 closed down. At 200mm your apertures will range from f/5.6 wide open to f/32 closed down. Or whatever the minimum aperture on that lens is.