Photoclubalpha

Having been spoilt by the CZ16-80 lens on the A700, I have been trying to get a zoom lens line up that will work as well on FF with the A900 for those sort of focal lengths.

Here is a quick review of what I have tried.

For wide angle:
Tamron 17-35/2.8-4
This works pretty well, a little corner softness, but low CA and probably better all round than the Sony 11-18 I used on APS-C.
It is reasonably priced, no doubt nowhere near as good as the forthcoming Zeiss 16-35.

For normal angle:

Tamron 28-75/2.8
Soft below f/4 - sweet spot about f/5.6, corners probably best at f/8, then diffraction above that limits resolution. AF micro-adjust settings depend on focal length to some extent with his lens.
Generally it front focussed compared to all of my Minolta/Sony lenses, before I calibrated the micro-adjust. For me this is an F/4 lens, as it is poor below that. There is no sign of uneven focus across the frame, so centering would appear to be OK. Currently this is the best zoom for this range that I have.

Minolta 28-105/3.5-4.5 RS
My copy has some blurriness on the LHS between 85 and 105mm, perhaps indicating some lens element decentering. Some CA visible, though CA not as sharply defined as lenses I used on APS-C. Even stopped down it is not as sharp as the Tamron 28-75/2.8 at the same aperture. Corners are not as sharp as the Tamron. Corner darkening at 28mm f/4 quite visible. I would not use this lens for really critical work like landscapes or architecture. It is fine for portaits, natural objects like flowers and I like the bokeh.

Saying all of that, these lens defects really only show up when pixel peeping at 100%. It is an unavoidable fact that with 24M Pixels, you will see the slightest lens aberration if you look at pixel level. I am trying to train myself not to view at 100%, but instead enjoy the photographs at full screen size, knowing that the print would also be perfectly fine at normal viewing distances. Incidentally the effects of slight camera shake even with SSS are more evident in the A900 files at 100%.

Ultimately, good primes may be the way to go for the best quality, or the expensive CZ24-70 and very expensive CZ16-35.

I have not had enough experience yet with my telephoto zooms on the A900 (70-300G and 80-200G), but will examine them next.

Sample of close up with Minolta 28-105 at 105mm


Larger size here (25% of original size)
http://www.pbase.com/braeside/image/106 ... iginal.jpg

Many thanks for this important info, David.

Very neat, David, thanks!

Yildiz

Nice review: I'm on the fence with the 28-75mm right now. I had the Sigma EX DF, but close-focus was horrid until f/5.6, so I returned it.

I'll throw out what I've gotten out of my extensive testing:

28-135mm f/4-4.5: As good as you've heard. Wide-open there is some CA, but @f/5 and above it is tack sharp with no CA corner to corner (in normal situations). Even 100% crops are fantastically sharp and clear.

Tamron 70-200mm SP: Just as good on FF as APS-C. Some CA and a touch of softness @ f/2.8, but stopped down to f/3.2 it is beyond amazing. The bokeh is old-style Minolta good and the focus is very good for small-medium transitions. Running from 1:4 - Infinity it is somewhat slow.

Minolta 50mm f/1.4: Again, just as good as it was on APS-C. SUPER sharp by f/2.2 with CA until about f/3.2.

Big Beercan: Very good all around. Best if stopped down to f/7.1 or so, but good even wide-open.

Minolta 35-70mm f/4: Stellar performer! Sharp with NO CA wide-open and very rich Minolta colors and bokeh. The macro function is particularly amazing because it doesn't seem to soften it up at all.

Anyway, I've got some more in my bag to test out, but so far the Minolta stuff is handling amazingly well on the uber-demanding A900 sensor.

lattiboy wrote:Minolta 35-70mm f/4: Stellar performer! Sharp with NO CA wide-open and very rich Minolta colors and bokeh. The macro function is particularly amazing because it doesn't seem to soften it up at all.

I've heard rumours that the newer version (3.5-4-5 I think) is even sharper (but lacking the macro mode?), have you tried it?

BR,
/Zeb!

[SiC] wrote:

lattiboy wrote:Minolta 35-70mm f/4: Stellar performer! Sharp with NO CA wide-open and very rich Minolta colors and bokeh. The macro function is particularly amazing because it doesn't seem to soften it up at all.

I've heard rumours that the newer version (3.5-4-5 I think) is even sharper (but lacking the macro mode?), have you tried it?

BR,
/Zeb!

Can't say much in comparison, but I do own the 35-70/3.5-4.5 and I like it very much (except for the range, of course).

I had both. I sold the 35-70mm f4 because the unsharpness wide open to the edges was not acceptable on the A900. The APS-C area was dead sharp all the way though. The later lens is better, I think, despite being less impressive in build quality.

David