70-400G - is it good enough?

Started Jul 13, 2011 | Discussions thread
ForumParentFirstPreviousNextNext unread
Flat view
ChuckB
Regular MemberPosts: 231
Like?
70-400G - is it good enough?
Jul 13, 2011

Just took delivery of my new 70400 and decided to compare it to my old Sigma 400 5.6 APO Macro. There have been a couple of reports of lemons, and with all this money at stake I figured I ought to check it out right away.

Better than the Sigma: focus speed, the fact that it's a zoom, build quality (I had another Sigma, same model, and my Maxxum 5D stripped its focus gearing - with SSM that should never happen).

Optical quality - see photos below. (The ones labeled 75-300mm are actually the Sigma - Sigma doesn't label lenses properly.) This is a test only of center sharpness. My subjects are birds, mostly, and edge sharpness is not really an issue for me. Both these lenses are FF so on my a55 I wouldn't expect edge sharpness to be a problem anyway. I used a tripod, SSS off. I focused manually on the white square (sticky paper) and got focus lock in the viewfinder. I examined the photos carefully to make sure that sharpest focus was not somewhere else - you see the best. The drive was set for a two-second delay to eliminate vibration from pressing the shutter button. In any case, both lenses received identical treatment. The only difference in the end was the odd exposure - at identical f stops the Sigma required more light and therefore a slower shutter speed.

So - comments?

ForumParentFirstPreviousNextNext unread
Flat view
Post (hide subjects)Posted by
ForumParentFirstPreviousNextNext unread
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark post MMy threads
Color scheme? Blue / Yellow