focus ring canon 17 X 85

[rwenglish1]

I was wondering, is it normal for the focus ring on this lens, to continually turn in one direction? It seems like on my old canon AE1 35 mm, the lens would turn one way or the other, then stop. I have a lot of pictures, that are a little out of focus. I am sure, that some of it, and maybe all of it, is from being hand held shots. Plus today, I did try shooting in the AV mode, set the arpture to 22, but could not freeze the action. And the focus seemed to still be fuzzy.


http://www.allmounts.com/backyard.html

[rent]

it is normal to be able to turn the focus ring past both "ends".

if you are shooting at f22, what is your shutter speed? too low of a shutter speed would definately cause blurry pictures.

if you want to test your lens's focusing, do it with your camera set on a tripod and preferrably with a shutter release cable.

good luck!

-alex

[pierrot]

Is it normal for the focus ring on this lens, to continually turn in one direction?
Continuously? Be more explicit, this sounds strange...

[Dew]

The focus ring has a friction clutch kind of thing going on, so you can keep manually turning the ring,
but it will start to slip as the focus gets to one end limit or the other. Is this what you mean?

[RichardtheSane]

The focus ring seems normal for a USM lens.

It is not designed to stop at the end of the scale, instead as Dew said there is a friction clutch thal allows you to keep turning it. The advantage of this is it allows more precise adjustments on the focus. Watch the scale when you turn the ring very slowly, soo how much more accurate it is!

About the shots on that link. Your shutter speed was too slow. The top shot you were down to 1/15th second, and I would imagine closing your aperture down to F22 caused this. Try setting your camera to TV mode and dialing a shutter speed of 1/125th (minimum) and you should get sharper shots. You could also try an aperture of F5.6-F8, this will also help.

Good luck!

[rwenglish1]

Continuously? Be more explicit, this sounds strange...

The focus ring turns easly clockwise, or counter clockwise with really no resistence, you can just keep turning it forever.

Thanks for all the comments, I will keep reading the book and learning the camera. rw

[Citizensmith]

Plus today, I did try shooting in the AV mode, set the arpture to 22, but could not freeze the action. And the focus seemed to still be fuzzy.

You've got things backwards. f/22 means a very narrow appeture opening which means a longer shutter speed is needed to get a correctly exposed image. To freeze action you need to set your shutter speed to something fast (such as 1/125 as suggested earlier or even better). For instance in the first duck photo you could have gone for f/5.6 and 1/250 which would have given a much sharper image.

Appetures past f/11 or f/16 will start to show diffraction effects (stars) around point sources of light. Additionally any time you use a lens at its extremes it won't be at its best. Basically only go for appetures beyond say f/16 unless you really have a specific need. f/8 is about the best appeture to have your lens on.

If you want a fast shutter speed and a narrow appeture you can increase your ISO. Your 20D can go to ISO 400 with very litte effect, and even ISO 800 is very good. At ISO 800 you could of had a 1/1000 f/8 image. Any softness left then would be down to missed focus from the camera.

[Citizensmith]

I just realised you may have been relying too much on the image stabilizer in your lens.

Sure it will give you 2-3 stops better handholding ability in low light, but it only corrects for movement in your hand. If the subject itself is moving (ducks, water surface, plants in the wind) it will have a motion blur if shot at low speed. IS is great in low light on static subjects, or for just adding a kick of extra stability in general use. However for moving subjects with slow shutter speeds there is nothing it can do.

[rwenglish1]

I just realised you may have been relying too much on the image stabilizer in your lens.

Sure it will give you 2-3 stops better handholding ability in low light, but it only corrects for movement in your hand. If the subject itself is moving (ducks, water surface, plants in the wind) it will have a motion blur if shot at low speed. IS is great in low light on static subjects, or for just adding a kick of extra stability in general use. However for moving subjects with slow shutter speeds there is nothing it can do.

Thank you Citizensmith, I can see, I do'nt know diddley yet, I will save your info, and practice it, I guess before with my AE1, I just left it on auto, and took pictures. But now I want to make better pictures. rw