Canon EF-S 18-55mm f/3.5-5.6 IS SLR Lens * above f/5.6? I recently bought the Rebel XSi that came with this 18-55mm lense. Since i'm still learning about what the camera can do, can someone help me out on fully understanding the limits of various lenses? If I'm taking a pic, and use the Aperture AV mode set to f8 or higher, how does that work when the lense says f/3.5-5-6? Is it a setting that will not be a true f8+ since the lense is limited to f5.6? As i've experimented with the camera, it's been very hard getting tack sharp images, even on a tripod. I finally disabled the automatic sharpening options, but have not tested the results to see if shots are any sharper. Also, a reviewer of this lense here, said to turn off the IS if the camera is on a tripod. But they didn't say why to turn it off, so i'm left assuming it's for sharper images. Thanks for any info!
That is the maximum (lowest number) aperature the lens can offer, not the minimum (highest number). The reason it is a range is because the maximum aperature will vary depending whether you are at 18mm or 55mm or somewhere inbetween. You will be able to set it to f/8 (or f/11 or whatever) at any focal length.
how can automatic sharpening not produce tack sharp images? I mean with a tripod and IS on why doesn't tack sharp images come about? I am thinking of buying this lens for a rebel xti that I just got. any help appreciate
If you are using a tripod, you should turn off the image stabilizer as it will actually impair the sharpness of the image by moving the lens slightly when it is already perfectly still. Another limitation (in terms of getting "tack-sharp" images) is the glass. the glass in the lens doesn't cost $1000 - so it won't be as sharp as a prime or L series lens.