Same here, but bloody annoying that you have to do it

John

There's a tendency for the lens not to lock focus between 50-70mm, it's well documented on several forums.

John

I found this in a thread on Photozone, a review of Teleconverters including Kenko (Teleplus) 1,5x SHQ, Kenko (Teleplus) 1,5x MC DG and Soligor 1,7x AF, primarily aimed at Canon users but useful for those who need a TC for their Telephoto lens:

http://www.traumflieger.de/desktop/telekonverter/konvertertest2.php

Tha pages (4) are in German but translate well when converted with Google.

John

I calibrate half way through the zoom range (approx)

John

I found I needed +5 adjustment on the DA-15 but it was no worse than some of the other lenses, it depends on the flange thickness of the mount on camera and each individual lens as they're all made to a tolerence. As an example I have these settings on the K20D:

SMCP DA 15mm +5
Sigma AF 24mm -8
SMCP FA 28mm +5
SMCP FA 35mm -3
SMCP FA 50mm -4
SMCP DA 70mm -8
Tamron Di 90mm +/-0
SMCP DA*16-50mm -6

John

That's an early Sigma, the finnish and focusing rubber changed on later models, but still nothing like the Exakta pictured.

John

Another vote here for for Sigma 10-20 f/4-5.6

John

Who, me?

"Nobody made a greater mistake than he who did nothing because he could only do a little."

John

April 21, 2011
26th CAPA Lens Grand Prix won by Tamron SP 70-300mm F/4-5.6 Di VC USD(Model A005)

The SP 70-300 mm F/4-5.6 Di VC USD (Model A005) has won the following prize. That telephoto zoom lens for full-frame digital SLR cameras is produced by optical equipment manufacturer Tamron Co., Ltd. (Headquarters: Saitama City, Japan / President and CEO: Morio Ono), which is celebrating its 60th anniversary this year.

Prizes Won

●26th CAPA Lens Grand Prix from the photo magazine CAPA
The same lens also won the European Zoom Lens 2010-2011, awarded by EISA last year, and the Gold Award in the 2011 Digital Camera Grand Prix from Ongen Publishing Co., Ltd.

This year marks the 26th time that the prize has been presented by CAPA, a hugely influential Japanese photo magazine highly endorsed by Japan’s photographers. The winner was decided after lenses nominated from new products were subjected to repeated testing and debate by all the committee members.

You have to take your hat off to its ultrasonic silent drive as well as its descriptive performance that is almost on a par with that of high-performance models.

The convenience of an angle of view equivalent to 450 mm with APS-C cameras also hits the spot.
The amazement of being able to purchase it for under 50,000 yen shatters initial perceptions that this is just another high cost performance lens.


[IMG]http://i884.photobucket.com/albums/ac49/johnwhit24/logo_CAPA2010.gif[/IMG]

Major prizes won by the SP 70-300 mm F/4-5.6 Di VC USD (Model A005)

* ● European Zoom Lens 2010-2011, awarded by EISA
* ● Gold Award in the 2011 Digital Camera Grand Prix
* ● 26th CAPA Lens Grand Prix

John

I'd go with the DA-70 personally, diminutive size, very discreet, fast AF and sharp wide open. I recently used mine for some candid portraiture at Cheshire Steam Fair along with the DA-15 and FA-35, one lens on the camera and a lens in each coat pocket, a real pleasure.

[IMG]http://i884.photobucket.com/albums/ac49/johnwhit24/Cheshire%20Steam/Nice.jpg[/IMG]

John