Macro: Pentax vs Sigma

Any outfit that reviews such a wide range of products is not worth taking any notice of IMHO.

I am sure that John R. or George L. or Clarky (to name a few) will be able to advise you, once they see this thread.

Try here for a start
https://www.pentaxuser.com/forum/viewtopic.php?t=7142

I love the D-FA100! It is a little noisy (AF-wise) but not considerably more so than any other Pentax lens (and at macro ranges you tend to use MF anyway) and there are times when the lack of a focus limiter can be, er, limiting but overall I find the optical quality to be absolutely first rate. The main advantages are the quick-shift focus and the incredibly light weight for a macro - these features I find make it much easier to use in real-world situations. I've seen some excellent shots taken with the Sigma (and the various Tamron 90 incarnations) but I wouldn't personally swap my D-FA for either of them to be honest.

Because the D-FA is such a featherweight lens it can give the initial impression of being "cheap&cheerful" but once you've used it you'll soon realise it's anything but! I'd put it level with my FA43 Limited in terms of outright IQ and that is no mean feat.

Couple of example shots (one at macro distance, one at near-infinty) - they may not be prize winners but that's more my fault than the lens...

That link is the first bit of negativity i have read about the Pentax

I agree with Hefty its a superb lens although i have not had this lens very long and not used it for portraits as yet. Also i have used it predominatly with a ring flash attached so i have been stopping it down somewhat and experimenting with it.

The guy who tested it said it hunts excessively : well i have been using the AF quite a bit, even with close up shots. and as you would expect it does hunt a bit, but not excessively so, and not as much as my Tamron 90mm, in fact i found i can control the Pentax better by feathering the shutter button to achieve focus lock.

In the wash up i would go with either of the 3, Pentax, Sigma, and Tamron. I don't believe you will be disappointed with any of them

Mybe the tester got a dud or he was having a bad day

I'd have a look at www.photodo.com to see if it's tested there.

I have used the D-FA lens but only for some test shots but it does seem fine. Sharp, crisp, nicely designed. For macro shots I don't use AF. Manual focus is much better for most macro subjects. But from what I've seen I would happily buy this lens.

I'm not buying the lens because I already have a FA 100mm f2.8 which I use quite a bit and is superb.

All the Pentax macro lenses are of the highest standard and I don't think you would be disappointed. The reviewer may have had a poor example, although it's unlikely, or may not be very good at testing macro lenses. Who knows, the parameters of the "test" are unknown.

I use the Sigma 105mm - and it is a superb lens. Lately I have started to use it as a prime as well - with excelent results. Frankly I'm so happy about it's sharpess that I'm considering to buy a 50/200mm macro to use as a prime....

I don't have the pentax model.....

The Photozone site www.photozone.de doesn't give the DFA 100 a particularly sparkling review either, looks pretty ordinary. The Tamron which is also tested on the Pentax K10D gets a better review as does the old FA100. Both the Tamron and old Pentax lens are more consistent from wide open with their quality hardly varying. It doesn't test the Sigma on Pentax but it does well on other cameras.

I have the old Pentax FA100 and it's pretty decent. Built like a tank so very heavy but it's the best built lens I've ever owned. Optical quality is fine although the contrast doesn't seem quite as sparky as I'd like for a Pentax lens. Strangley I find that the M series lenses have better colour, contrast and purple fringing characteristics than the FA lenses. I don't use it much as I tend to use the 50mm version instead as it's more handy.

One word of warning, I did buy the old version Tamron 90mm it was auto focus but not the digital version, the colour cast and purple fringing were appallingly worse than any other lens I've ever seen truly horrible so I wouldn't get a 2nd hand one unless you can try it.