[azcavalier]

So would you feel comfortable replacing the kit lens DA-L 18-55mm with it? That is what I am debating. I want to grab some primes but can only afford one lens at a time. The 40mm limited looks to be the sharpest and least expensive of them all. I saw one on eBay for 300 bucks.

I would, if you can afford it. The Sigma is just a better lens. Better IQ. Also give the Sigma 24-70mm some serious consideration.

My plan is to also, someday, get a "portrait" prime. Like a 77 or an 85. Those two lenses are all I need.

[pop4]

Not so. I bought this lens to pair with my K-5 IIs. The Pentax version does *not* have OS on it. You can see where that switch would be on the lens body, but it's just not there. While it's not clearly stated in any online sales description that I have yet to see, on B&H's site, if you go to the specifications tab on the lens' site, it does show that the lens is not optically stabilized.

Just for information and for a quick history lesson, when the Sigma 17-50mm F2.8 was initially released in mid to late 2010, it did have OS in all mounts that it was release for: Sigma, Sony, Nikon, Pentax and Canon. dpreview article available HERE. And in fact, the lens in stormtech's post above is my very own Pentax mount, Sigma 17-50mm F2.8 EX DC OS HSM, bought in September 2010.

Then, at the end of 2011, Sigma announced the launch of the Sigma 17-50mm F2.8 EX DC HSM without OS, for Pentax and Sony mounts; with the launch of this non-OS version of the lens, the OS versions were discontinued. dpreview article HERE and Sigma Japan press release HERE. So any store selling a Sigma 17-50/2.8 with OS in Pentax mount is either selling old stock, or aren't being very accurate with their product descriptions if they are actually selling the non-OS version.

So when Class A made his "Too bad that Pentax shooters have to buy the OS whether they want it or not" comment in Jun 2011, before the release of the non-OS version, at that time, he was correct.


And having owned the lens for close to two and a half years now, what do I think? Well, I don't use it, or even my Pentax gear as much any more as my shooting style has changed, but it's still a damn good lens. Sharp and fast, pretty much as fast as you'll get with a zoom lens, and I'll take HSM over screw-driven focusing any time. It also serves as a great workhorse lens; I've done plenty of event work with the 17-50/2.8 on one body and 70-200/28 on the other.

[Digitalis]

It's quite interesting that both of you mentioned compactness as one of the advantages primes have over zooms, but personally, it's not something that bothers me

Right, If you have ever travelled as a photographer and only had so much room in your carry-on sized camera bag then size does become an issue.


Please bear in mind that for every step forward in optical quality zoom lenses take primes take two, and I don't consider many sigma zoom lenses to be all that good anyway (In fact some of their primes are very average optically speaking, not to mention construction quality). Even the best zoom lenses really need to be stopped down at least two stops to get the best out for them and even there there are ways to spot the difference between a prime and a zoom lens. And for the record: the original Carl Zeiss 35mm f/2 can heartily belt the crap out of any sigma lens* of similar focal length ever made.


*Both optically and in terms of construction quality, those lenses were made to last - also I'm not talking about the current Zeiss 35mm f/2 which is made without the use of leaded glass (which almost always changes the optical design and performance) which is actually made by Cosina. I'm talking about the Made in Germany Carl Zeiss lens for Contax.

[pop4]

It's quite interesting that both of you mentioned compactness as one of the advantages primes have over zooms, but personally, it's not something that bothers me.

Right, If you have ever travelled as a photographer and only had so much room in your carry-on sized camera bag then size does become an issue.

I said that back in 2011, and how things change with time. Size is the reason why I rarely shoot with a dSLR anymore and I now shoot primarily with the Fujifilm X-Pro1 and it's 18/2, 35/1.4 or 60/2.4 lenses or the Leica M6 with Zeiss ZM 35/2 Biogon (not the one you're talking about either).

[Digitalis]

Leica M6 with Zeiss ZM 35/2 Biogon

Very nice, I have used that lens and without correction it vignetted really badly on the Leica M9, you also get some really bizarre colour casts out towards the corners on the M9. I use the Leica 35mm f/1.4 Summilux ASPH more these days, the physical size difference between f/2 and f/1.4 isn't as large with rangefinders than it is with SLR cameras.

[jkglogau]

SO how do we explain the difference in the ratings in the forum lens database - 9.20 for the non OS v 8.57 for the OS??????????