Mine came from Cameta as well. Agree on the lens cap and the way zooming works. Not all Sigmas are like that though - my 10-20 zoom works the normal way.

The Tamron lens caps (as fitted to the FA 28-200 Pentax) are definitely the best for removal and replacement when a hood is fitted.

To answer my own question, the Sigma arrived this morning from the states and first impressions are pretty good. It's a fairly hefty lens (similar in size to the FA 28-200 but heavier) and seems well built. The viewfinder image appears bright and crisp and it'll be interesting to see how it performs in the field.

My walkabout kit looks like it's going to be the 10-20 and 24-135 Sigmas plus a 7 element 2x convertor for when more length is needed.

I'm looking for a walkabout lens to match up with the Sigma 10-20mm I have on order and this focal length range appeals to me. I've read some online reviews however I'd be interested to know if anyone here has actually used one of those.

I can get one from the US for about the same price as my SMC-FA 28-200 should make if I sell it on Ebay.

Digital cameras need the light to hit the sensor from as close to perpindicular as possible. Any light that doesn't can cause chromatic abberations and it's for this reason that we see measures being taken now to address this with new lens designs, including measures internally to cut down reflections. Some lenses have internal baffles to cut down internal reflections and others have coatings were none would have been used before.

I've not used either of the lenses you mention, however my own 85mm lens (the FA*) was produced before the digital era and doesn't appear to suffer from chromatic aberattions - in fact the only lens I have which was specifically designed for digital (the 18-55 kit lens) suffers to a more noticeable degree (although it's not bad either).

SPB: On my first outing with the mirror lens I also took some shots of a swan and they were very similar to the one you posted up. Most of the well composed ones I took that day were a tad out of focus though (one would have been a cracker as it had water dripping from the beak after the bird had brought its head back up from under the water), so for the second outing (the one when the gull pictures were taken) I concentrated a lot more on exactly where the focus point was and my success rate jumped quite a bit, although without viewfinder focus aids it's not easy to focus correctly on the subjects eye. I also had a few which were affected by camera shake which is why I later tended to err on the side of caution and use a faster ISO. Given this was on a DSLR I also took lots and lots of pictures as that pretty much ensured I'd get some right!

The third time I used the lens was for the garden shots and again my success rate with focusing improved so it does seem to be that a little practice is what's need - so I'll be looking forward to the results of your next shoot.

Just been out in the garden and took a few more shots with the Tokina, to give some idea of its versatility:










It's close focus capabilities are quite impressive, however it's difficult to focus accurately as the DOF is very small when the subject is that close.

Regards
Steve

Here are a few examples I shot that day using the 500mm Tokina:













These were all shot handheld, mostly using ISO 800 I think. None of the ones I took of birds in flight with the mirror lens were sharp enough to use as I wasn't accurate enough with focusing. I did get a few reasonable ones using an 80-200F2.8 and a 7 element 2x convertor:




Regards
Steve

What I've found so far is that the Tokina mirror lens is capable of good results as long as your accurate with the focus, something not as easy on my DS as it is on my Z1p (because the Z1p viewfinder is much, much better than the DS one). That makes moving targets very hard work, however with static subjects it's usually ok. At shorter distances the focus depth is pretty small and the lack of manual focusing aids in the DS viewfinder means that it takes some concentration to confirm that you are focusing on the right area.

We had a family day out to an island in the middle of the river Forth yesterday and as its home to a large bird population (as well as a historic abbey and some wartime fortifications) it was the first chance I'd had to use the mirror lens properly.

Fitted to the DS the handling and balance was fine and handholdable speeds were no problem with the ISO set to 800. The quality from shots of static seabirds seems pretty decent, however capturing birds in flight was a lot more difficult and more practice will be required to get a better hit rate. I also had my 80-200 F2.8 Tokina and a 7 element 2x convertor and with AF-C available my hit rate with in-flight birds was a lot better. Even wide open (handheld again) the results using that combination seemed more than acceptable.

The Sigma is supposed to be a good lens - as good as the Tamron, perhaps even better. £500 is steep though as on Ebay they'd typically make £70 or so.