canon 7d and sigma 500 f4.5

bazzaboy09 · #1 (**permalink**) 15-12-2010, 03:31 PM

Guys, I have had the sigma 500 f4.5 and my shot are not that sharp as i have seen with the same lens in the Gallery, And i am just wondering if the camera and lens should be calibrate to get the desired shot.
hope you can help and thank you.

triops · #2 (**permalink**) 15-12-2010, 05:32 PM

Hi bazzaboy,

I don't really know the answer to your question. However, looking at your picture it seems that the bird is not in focus, that the plane of focus is just in front of the bird. Perhaps the camera is focussing on the grass. Possibly there is a way of instructing the camera to focus on the subject in the centre of the screen. Hope this helps.

squishy · #3 (**permalink**) 15-12-2010, 05:58 PM

The grass in front and behind the bird also looks a lot softer than you'd expect, so it doesn't look like front/back focussing.

I'd be getting that lens checked by sigma.

SouthwestSnapper · #4 (**permalink**) 15-12-2010, 06:15 PM

What f-stop was used and what shutter speed? I dosent look like a really bright day.. could this be a combo of slight camera shake and shooting wide open???

Need more info please???

Nothing in that shot is really pin sharp, if you tell me it was shot a F11 and 800th sec then there is a fault with the equipment..

If it was at F4.5 and hand held @ 125th then,,well ...

luv SWS

squishy · #5 (**permalink**) 15-12-2010, 06:43 PM

Tiny amount of camera shake may be the cause if it's handheld or slow exposure, but this lens should be sharp wide open.

johnf3f · #6 (**permalink**) 15-12-2010, 09:54 PM

It looks as though things are not quite right, though you can't judge on just one shot (or a couple for that matter). The first thing to do is type "FOCUS TARGET" into Google and have a look at the free ones available. Print off one with a distance scale as these are normally intended to be mounted at 45 degrees. When you photograph the target (at max apeture) you will soon see if there is a tendancy to front or back focus and you can then adjust accordingly. Remember to make your final settings at the "normal" range that you will use the lens. Your camera is able to remember the settings for a number of Canon lenses (I believe it will remember your Sigma). If it's still not OK then back to the shop!