soft focus after tight zoom

[David Morgan]

after doing the standard procedure of zooming in all the way for manual focus, I notice that when I pull out, the image seems slightly out of focus.

Here's the situation: Doing stage shows, camera is about 60 feet from stage. Zoom in, focus, then pulling out for a wide shot, images seems soft. Shows that way in post. Is this just the best a 1/3" chip camera can do?

[Chris Soucy]

Not something I've ever seen on my A1.

With the depth of field offered by the wider lens angle, even the inevitable minor differences due to manufacturing tolerances should be invisible, and they are with mine.

If this is a new cam or a problem new to this cam, I'd suspect some form of fault with the lens mechanism, but as to what, I can't even hazard a guess and user fixable NOT, regardless.

If it's noticeable enough to drive you to distraction, well, you know where this is going - Canon Service.

Sorry, can't offer any better advice, although...........hang on, stage shows?

Stage lighting?

How wide are you going and what's the aperture going to when you pull back, flat chat open?

What aperture are you at when doing the focus zoomed right in?

Just a suggestion, lock your aperture and let the shutter speed do the walking (if possible) 'cos if focused at f8 it sure as hell won't be, wide open.

Else, set your aperture for max, do the zoom in and then focus, if it's tack sharp full open at max zoom, then it should be tack sharp full open with the lens pulled back.

If it's still not right, go to Para 4 above.


CS

[David Morgan]

not a new camera. same problems for a couple of yrs which led me to post.

Since shows are wide dynamic range (lighting), I always shoot with 1/60 shutter and work the iris for widest exposure using the zebra as my guide.

Close up shots from 60 ft (full zoom in) then have to widen out to cover a stage width of about 40 or 50 feet.
Thats when I loose light and the shots just look soft. They look soft in post as well. Maybe it's just as good as it gets with 1/3" chips but I can't get it sharper no matter what I try.

Think it might be dangerous to shoot with shutter priority because brightly lit shots could cause too slow a speed and the results might be blurry

[Chris Soucy]

I didn't express myself very well in my original post.

The point I was making was that you need to do the initial "full zoomed in" focus at maximum aperture, when the lens is at it's weakest.

If you nail it tack sharp at maximum aperture then, it SHOULD be tack sharp for whatever you do subsequently.

If you're shooting below the A1's light floor, well, who knows, never tried, but I guess it would get a bit sad.

Sorry, best I can do.


CS