If you're considering selling the lens in 3 years then I'd suggest you've bought the wrong lens anyway! The difference in eventual re-sale over that sort of period isn't likely to offset the difference in initial purchase costs anyway - unless you can find a way to purchase the DA12-24 for under say £400.

The photodo web site has reviews of both lenses in a Pentax mount and their test numbers show the Sigma as actually having less distortion across the frame at 10mm than the Pentax has at 12mm, with the Pentax being a little better at the longer focal lengths. Both are pretty good for such wide angles though. Both lenses are also closely matched for resolution, the Pentax is better for vignetting (both are pretty good) but noticeably worse for CA. Such test results always have to be taken with a grain of salt given they're only based on a single sample of each, however what they do seem to indicate is that the lenses are very well matched, and both very good, optically and therefore the purchasing decision comes down to how much value you (and the re-sale market) put on the Pentax brand compared to a 3rd party one (given the Pentax lens is a joint venture with Tokina anyway) and whether than, plus the handling differences and the constant F4 aperture (certainly worth having although less so in an ultra-wide) offet the lower price and additional width of the Sigma.

When I bought my Sigma I could (and eventually did) get it and the DA16-45 for less than the cost of a DA12-24 and that made the decision a lot easier for me.

The Sigma is also a reasonably bulky lens - it's inevitable given the focal length range etc.

£429 would be very expensive for the Sigma - warehouse express sell it for £289 (and they list the Pentax 12-24 at £629).

If the Pentax were only slightly more expensive than the Sigma, as John indicated in the prices quoted, then the higher re-sale of the Pentax would make it worthy of consideration (although I'd still be tempted by the extra width of the Sigma) - but with a difference really more like £200 in the UK it's a very easy choice IMHO.

I'm sure I'd have been more than happy with either lens though. I had the option of getting a DA 12-24 for £350 when my wife was in Singapore a year or so back but eventually I decided to stick with the Sigma I already had and get her to bring me back a DA10-17 instead.

I'm scanning some films from years back and this was a shot I liked of a Hong Kong street at night. It was taken on Fuji 800, almost certainly handheld and I suspect using the FA* 85mm F1.4 & MZ5 (I often used to wander about with just those and a FA* 24mm F2).




I prefer it in B&W, however here's the colour version for comparison:

I don't know that one - all the manual focus Vivitar macro lenses I was aware of went to 1:1 without an adaptor.

I think there was a Vivitar/Kiron 105mm macro that is supposed to be superb, however they're fairly rare and tend to command quite high Ebay prices.

There are also a couple of Komine build macro lenses badged as Vivitars (I have the 55mm) and those are also very sharp but a lot cheaper (I can'd recall exactly what I paid for my lens but it was in the region of £30 I think). These can be found from time to time on Ebay although the prices seem to be increasing (as they are with many Pentax fit lenses now).

There are a few cheaper options you might want to consider as well:

1) Manual focus lenses - there are lots of these pretty cheap, including Pentax ones. Manual focus isn't a problem for macro shooting (it's more reliable than AF anyway) however it might limit the lenses usefulness for general purpose stuff. With older (pre KA) lenses you'll need to work out the exposure when stopped down manually as the K10D isn't accurate with small apertures set.

2) Cosina 100mm F3.5 macro (or the Pentax badged version of the same lens) - It has AF (noisy but fast & accurate) but only goes to 1:2 (although an optical adaptor is supplied for 1:1) but is good optically.

If you're going to be doing a lot of Macro shooting then the Pentax/Tamron/Sigma AF options would definitely be your best option.

Unless you're looking for a small lens then the Sigma 70-300 APO Macro is a better option than the Pentax 50-200 and they're about the same price (the Sigma is faster, sharper and has useful macro capabilities). The Sigma is also frequently available used.

I've never used the Tamron 70-300 but I've seen some posts from folks saying it's a good lens.

All donations to my 645 lens fund gratefully received...

I wouldn't touch it if I were you, and I'd be wary of any consumer telephoto that's slower than F5.6 at 300mm.

I paid something like £67 on Ebay for a 2nd hand Sigma 70-300 APO Macro and that is a much, much better lens than the one listed.