[gerax]

So I was kinda decided for the Sigma 10-20 HSM as my next wide angle lens, when the Pentax 10-17 pops up...

Reviews on this very forum give the Pentax a 9.2 against an 8.7 (8.8 for the 3.5 version) of the Sigma, plus it's 3.5 while to get the same aperture on the Sigma the price ramps up quite a bit (although it's 3.5 on all the focal range). I know some pretty nasty purple fringing on the Pentax it's a bit of an issue and the Sigma looks sharper...so...

Does that half stop really matter? Does the HSM AF really makes a difference (the non HSM version can be had cheaper)? Anybody actually compared Sigma and Pentax side by side?

Thanx

[enoeske]

So I was kinda decided for the Sigma 10-20 HSM as my next wide angle lens, when the Pentax 10-17 pops up...

Reviews on this very forum give the Pentax a 9.2 against an 8.7 (8.8 for the 3.5 version) of the Sigma, plus it's 3.5 while to get the same aperture on the Sigma the price ramps up quite a bit (although it's 3.5 on all the focal range). I know some pretty nasty purple fringing on the Pentax it's a bit of an issue and the Sigma looks sharper...so...

Does that half stop really matter? Does the HSM AF really makes a difference (the non HSM version can be had cheaper)? Anybody actually compared Sigma and Pentax side by side?

Thanx

The 10-17 is a fisheye. Very different from a rectilinear wide angle.

[pathdoc]

Wait a moment - if I'm not mistaken, the Sigma is rectilinear and the Pentax is a fisheye. They are chalk and cheese; apples and oranges. Pentax's ultra-wide rectilinear zoom is the 12-24, which is f/4 all the way.

Apologies for repeating enoeske's point - that post came in while I was still typing and I didn't see it until after I clicked post).

[gerax]

...I see....didn't take that inot account...

Infact I see the distortion in the Pentax is way higher than the Sigma, now I understand the reason...

[ChristianRock]

...so basically, you need both

[gerax]

Well...my Idea was to have a better qualty lens than the 18-55 kit lens I'm using now with a wider angle, thus the Sigma 10-20...

[reeftool]

The Sigma 10-20 is a fine lens. So is the DA 12-24. The DA 10-17 is a fisheye. I love mine and use it often but it can't take the place of a rectilinear. It's very versatile and with proper framing, the distortion isn't bad but it's always there and you can't rely on software to correct it. My other wide angle, besides the 10-17, is the DA 15 Limited. It's reputation is legendary. You might also look at the DA 21.

The HSM lenses are much quieter but probably a little bigger. I don't own the 10-20 so someone who owns one might chime in. There is no lack of wide angle options for Pentax cameras and to make a buying decision even more difficult, they are all pretty good lenses. I chose the DA 15 because of it's small size and light weight. It's a little wider than I often need but the IQ is good enough that I have no second thoughts about cropping.

[UncleVanya]

Maybe I'm confused but my impression of the 10-17 is that it is Fishy on the 10mm end and pretty Rectilinear on the 17mm end. Am I confused?

[Just1MoreDave]

It's less fishy at the 17mm end. What I remember in use is the angle of view at 17mm matches the DA 12-24/4 angle of view at 12mm. If you have a scene that doesn't make the fisheye distortion obvious, shooting at the 17mm end helps hide it further, or allows you to use software correction more successfully. But you'll be happier if you always think of it in fisheye terms and sometimes fool people into not noticing.

[BrianR]

Maybe I'm confused but my impression of the 10-17 is that it is Fishy on the 10mm end and pretty Rectilinear on the 17mm end. Am I confused?

At 17mm your picture looks a crop of the 10mm setting (with correspondingly more pixels of course). The type of projection this lens uses looks "less fishy" in the middle. Hence, it looks much closer to rectilinear at 17mm - straight lines are straighter but they will still have a pretty wicked curve.

edit- see the photo of the test grid @10mm and 17mm here http://www.photozone.de/pentax/132-pentax-smc-da-10-17mm-f35-45-edif-fisheye...report?start=1

[robthebloke]

If you need ultra wide, then the DA 15mm is impossible to beat. If you need stupendously wide, then the sigma 8-16 is not a bad option. I've tried virtually every offering in that range that are available new, those would be my two choices. If you have the da15, there isn't really a reason to have anything else.

(I've tried: sigma 8-16, da 12-24, sigma 15-30, da15, k18, a20, da21)

The da21 is worth a special mention - if you're after something wide, that can cope with being a standard, and has nice bokeh

[Jonathan Mac]

The 15mm isn't what I'd call an ultra-wide, and bear in mind it's not sharp at the edges until f/8 or more, but it is much smaller and lighter than any other option at that focal length. I understand that the slower Sigma 10-20 is optically better than the faster version, but it really depends if you need the extra speed.

[AquaDome]

I have both the Sigma 10-20mm/4-5.6 and the Pentax DA10-17mm Fisheye. They do not serve the same purpose and are not interchangeable. I use the 10-20 for architecture and indoor photos. The 10-17 fisheye gets used outdoors for landscape and nature stuff where there are no man-made straight lines.

[redrockcoulee]

I still have the 17 28 FE and the 15 da and my wife a 10-20 Sigma. The FE would be my last choice which is the reason I will sell it someday soon. I really like my wife's Sigma but 8 like the da 15 even more. I would probably recommend the 10-20 due to it being so much wider than the kit lens or the 15. You can always pick up the 15 is you find you shoot alot of uwa.

[j0n4hpk]

If by any chance you get to sample a Schneider-Kreuznach (Samsung) 12-24mm F4 ED D-Xenon lens for Pentax K mount, give it a try. This lens was produced for the Samsung GX-series (similar to the Pentax K10D, K20D series) and it's equivalent to the DA 12-24mm one.