[ronyzmbow]

Looking for a lens to replace my kit lens on a Pentax K-10D.
The decision is between Pentax 18-135 and Sigma 17-17 mm. I am fully aware of all the differences between the 2 - my main main concern is image quality and sharpness. Are they equal in terms of sharpness?
Can the Sigma lens create the beautiful colors that Pentax lenses produce?
How can one compare the mechanical quality of these lenses?
Many thanks for the help I can get!

[JinDesu]

I assume you mean the Sigma 17-70? F2.8-4 or F2.8-4.5 older version?

I don't have the 18-135, but I can say that my Sigma 17-70 F2.8-4 is a very good lens. It's quite sharp through most of it's range, being a bit weaker at the long end. It renders very cool (blue) compared to my DA 35 F2.4 and my older DAL 18-55. Some people may not like the colors it produces because it renders so cool - but post processing brings it back to normal. The build quality of my 17-70 is pretty solid - there isn't a lot of zoom creep as the zoom ring is well damped

Now things that I think the Sigma 17-70 is bad at compared to the 18-135:
1) The zoom ring rotates differently than Pentax zooms. It can be annoying.
2) The AF on the Sigma 17-70 is quiet, but it's probably not as fast as the 18-135.
3) It has OS and AF switches - OS isn't necessary on Pentax cameras, and the AF switch is just one more step before I can use manual focusing mode.

[abmj]

I think you meant to say the Sigma 17-70mm ?

Speaking for just my copies of those two lenses, I find the Sigma to be a tad sharper, a lot heavier and a little bulkier. I appreciate the Macro feature which permits me to get pretty close without carrying a separate lens. It is my walk-around lens when weight and extra equipment don't matter, such as when traveling by car or carrying my full kit around.

On the other hand, I find the Pentax to be more convenient for travel as it is smaller, covers a much wider range thus eliminating carrying of extra lenses, is WR and is ALMOST as sharp. It is my single lens travel solution and I also use it as a walk-around in sketchy weather.

YMMV.

[Cambo]

Looking for a lens to replace my kit lens on a Pentax K-10D.
The decision is between Pentax 18-135 and Sigma 17-17 mm. I am fully aware of all the differences between the 2 - my main main concern is image quality and sharpness. Are they equal in terms of sharpness?
Can the Sigma lens create the beautiful colors that Pentax lenses produce?
How can one compare the mechanical quality of these lenses?
Many thanks for the help I can get!

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/193399-issue-s...-ex-macro.html


I am completely against ANYTHING from Sigma. IMHO. You're free to be foolish with your money if you want.

Cheers,
Cameron

[Digitalis]

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/193399-issue-s...-ex-macro.html


I am completely against ANYTHING from Sigma. IMHO. You're free to be foolish with your money if you want.

Cheers,
Cameron

I wouldn't be that black and white about it, My sigma 100-300mm f/4 APO EX DG has done impressively well. It is one of the few lenses I have bought for my pentax cameras that has managed to pay for itself. Pentax has made some incredibly average lenses in their 50 year history, do you happen to remember the Pentax FA-J lenses? none of them can match the FA limited lenses that is for damn sure.

[panoguy]

do you happen to remember the Pentax FA-J lenses?

I thought we all agreed not to speak of them in polite company?

[vrrattko]

https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/193399-issue-s...-ex-macro.html


I am completely against ANYTHING from Sigma. IMHO. You're free to be foolish with your money if you want.

Cheers,
Cameron

Why so negative about Sigma? Some of their EX lenses (30/1.4, 50/1.4, 85/1.4, 50-150/2.8, etc)have impressed many accomplished amateur photogs even on this forum....check for example Sigma 30/1.4 club. You'll find many cool fellow pentaxians praising that len over there...

[GabrielFFontes]

I bought a Sigma APO EX 70-200 2.8 and it came with a focusing problem, so be sure to check it before.
Even though my experience with Sigma isn't the best one (1 lens, 1 problem), i can't say i don't recommend it. The lens, when focused using live view, is incredibly sharp even wide open, and the focus is REALLY fast...

[panoguy]

Why so negative about Sigma?

Reading the linked thread (which is more about old vs. new Sigma coatings, than bad vs. good), one of Cambo's friends had a bad experience with a Sigma lens more than a decade ago. So the rapid-fire slagging of Sigma is truly well-reasoned and insightful, and based on critical experience...

[Digitalis]

Every manufacturer makes a lens that I don't like, even Leica has made two lenses in the past* that I simply cannot fathom why people buy them. Sigma has a few bad lenses - usually cheaper ones. Tonkina has made more than a few, so has Voigtlander, Nikon, Zeiss, Contax,Canon,Olympus,Minolta etc,etc so on and so forth.

Just because a few Sigma lenses are bad doesn't mean all of them are (though I have yet to see anyone make a perfect lens for a 35mm camera, Leica comes pretty damn close)


* Leica 135mm f/4 Tele-Elmar-M , because it nearly always misfocuses on modern RF cameras - you need a really high magnification greater than the .72 that is common these days to be accurate with such a long focal length (Though the Leica M3 has .91 magnification which is perfect for longer RF lenses, and the Nikon SP gets a honourable mention for having 1.0X magnification) and the other Leica lens I do not like would have to be the Elmarit 90mm f/2.8 Macro - I prefer to do my macro work on a SLR because that way at least I can see the focus errors coming.

[Cambo]

Reading the linked thread (which is more about old vs. new Sigma coatings, than bad vs. good), one of Cambo's friends had a bad experience with a Sigma lens more than a decade ago. So the rapid-fire slagging of Sigma is truly well-reasoned and insightful, and based on critical experience...

read up about them. There have been LOTS of issues with that company and their products, not the least of which had them TAPING ON the front element of a lens costing more than $2,000.00. Appalling. I will never trust them again; you're free to if you want.

IMHO, we shouldn't reward corporations who put out products like that.

Sincerely,
Cameron

[abmj]

Oh Bulls**t!

[Digitalis]

TAPING ON the front element of a lens

Exaggerate much?

[Cambo]

Exaggerate much?

Look it up. Documented throughout the Pentax geek forums back in the late 90's. Many instances of the element coming loose, and people shocked to see that it was taped on. Apparently Sigma used it as a primary means of construction for several of their lenses back then.

Here's one of the first one's that came up with a Google search:

http://www.photography-forums.com/happy-enigma-crappy-sigma-t100656.html

Cheers,
Cameron

[Digitalis]

Apparently Sigma used it as a primary means of construction for several of their lenses back then.

And apparently Canon are still using it - on their L "luxury" lenses too - this lens was a 50mm f/1.2L that cost thousands of dollars, until it broke in half. As far as I know Canon repaired it free of charge, but they probably just replaced the broken front cell and re-glued it.



All i'm saying is that sigma isn't alone in making bad choices in lens construction - the other major players have also made some egregious bloopers themselves. The only lensmakers that have managed to avoid this are Leica, Voigtlander and Zeiss.