[English-Photographer]

The Pentax K1 sensor is pretty great, and is even better with pixel shift mode. I have some relatively sharp lenses like the 31mm, Sigma 85mm, 28-105mm and the Porst 55. But the Samyang 135mm f2 is in another league entirely. It's manual focus and heavy but optically it's incredible. Is it the sharpest lens available for the Pentax K1?


Here's a full resolution photo with it just for an example.

https://farm1.staticflickr.com/556/32300012061_055ef5a3d4_o_d.jpg

[Na Horuk]

I've read some great reviews of that lens and it is very attractive, particularly the lack of CA and very clear photos.
I think the "sharpest lens" threads usually mentioned the following a lot: DFA 50mm, DFA 100mm, DA* 55mm, FA 77mm. Some of these suffer of purple fringing or some CA wide open, though
These days Sigma 35mm Art and some Samyang lenses, like the 135mm, might be too much for those "old lens designs."

Looks like Pentax is working on revamping its lineup in the coming years, though.

[English-Photographer]

I have the Dfa 50mm and it's not really sharp. The 100mm might be special. Haven't seen...

[HarisF1]

I think I'm right in saying that sharpness would be tested more on a high res APS-C body like the K-3 than the K-1, yes?

[lithedreamer]

Here's one of my photos from the D-FA 100 @ f/5.6 for reference:

https://farm1.staticflickr.com/557/31169371310_1358113357_o_d.jpg

[From1980]

Samyang lenses like the 135 f/2 certainly seem desirable for the price and it's great to hear of good results using them. However, issues with the company's quality control and consistency of their product keep coming up in discussions. Is anybody reporting that is improving?

[clackers]

I have the Dfa 50mm and it's not really sharp. The 100mm might be special. Haven't seen...

It's very sharp, EP - check out the incredible performance of its ancestor, for instance:

http://www.takinami.com/yoshihiko/photo/lens_test/pentax_normal.html

Perhaps you have a dud copy - mine did these:

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Last edited by clackers; 01-21-2017 at 05:03 AM.

[Rondec]

Sharpest lenses I have used -- DFA 100 macro WR and probably DFA 70-200 f2.8. The zoom, if you have a good copy is amazingly sharp at f2.8. I haven't used the Samyang (not a big manual focus person), so I can't compare. Seems like macro lenses feel sharper in general due to their flat field.

[Digitalis]

Is it the sharpest lens available for the Pentax K1?

There are probably sharper lenses out there. some of the Voigtlander SL series lenses. Older Zeiss/Leica glass and the newer zeiss otus line of lenses when adapted to K mount could beat it easily...also there is the pentax SMCP-FA*200mm f/4 ED Macro which is the benchmark for resolution among all 200mm lenses out there.

[Na Horuk]

There are probably sharper lenses out there. some of the Voigtlander SL series lenses. Older Zeiss/Leica glass and the newer zeiss otus line of lenses when adapted to K mount could beat it easily...also there is the pentax SMCP-FA*200mm f/4 ED Macro which is the benchmark for resolution among all 200mm lenses out there.

Hey Digitalis, what do you think of the modern Samyang primes? Many are quite well-corrected and very sharp, and QC problems are smaller and smaller with the new stuff

[Digitalis]

Hey Digitalis, what do you think of the modern Samyang primes?

Samyang lenses are rather difficult to get a hand on here in Oz. I like to buy my lenses from B&M stores that have good return policies*. I have test data from colleges in the EU and the data looks promising, but it is from a rather limited sample size. As you mentioned QC is problematic: I won't publish test results from a bad copy of a lens, it just isn't fair. I will test a bad copy, but only to use it as a data point regarding consistency of a particular lens makers product portfolio. And to be perfectly frank: Samyang look pretty bad regarding defects**.


* And the B&M stores that I work with are well aware of my stringent optical and physical construction standards. The store managers hold my opinions in high regard, as I bring my test data with me when I have a complaint about a particular lens.

** especially as focal length decreases. As a rule, longer lenses are more difficult to mess up.

[normhead]

I just can't bring myself to embrace manual focus. I shoot with my A-400 for manual focus, from time to time, but it's not good for everything. With small quick moving birds manual focus can cost you an opportunity entirely. Thinking the image would have been really sharp if you had captured it is little consolation.

It begs the question, what do you want to do behind the camera. Do

Do you want to observe your subject, wait for the best possible pose, move around looking for better backgrounds or angles, or do you want to spend half of it trying to perfect your focus?

The only time manual focus is competitive is if I stop to select a different point in the AF grid. An MF guy might be faster. But even then, it would be a contest.

And as a general rule, people's opinions of which lens is sharpest, are for the most part pretty meaningless. After a certain degree of sharpness, it's about the picture, not the glass.

Focal length and aperture are pretty real concepts. Sharpness is surrounded in CA, micro-contrast, contrast lighting and many other factor, all of which might influence what the poster might call sharpness.

[Digitalis]

I just can't bring myself to embrace manual focus.

I rarely use AF for anything these days. I know my camera focusing screens "snap" I know my lenses: With pentax I have a small working set : Sigma 8-16mm f/4.5-5.6, Pentax DA-15-30 f/2.8, FA31, SMCP-K 50mm f/1.2, FA77, Leica-R 90mm f/2.8, Pentax FA*200mm f/4 MACRO*, Sigma 100-300mm f/4, Pentax FA*300mm f/2.8, FA*250-600mm f/5.6.

Some of my lenses don't even have focus rings that turn the same direction!

*Sometimes substituted for the Sigma 180mm f/3.5.

[normhead]

I'm the complete opposite, I rarely use AF for anything these days. I know my camera focusing screens "snap" I know my lenses: With pentax I have a small working set : Sigma 8-16mm f/4.5-5.6, Pentax DA-15-30 f/2.8, FA31, SMCP-K 50mm f/1.2, FA77, Leica-R 90mm f/2.8, Pentax FA*200mm f/4 MACRO*, Sigma 100-300mm f/4, Pentax FA*300mm f/2.8, FA*250-600mm f/5.6.

Some of my lenses don't even have focus rings that turn the same direction!

*Sometimes substituted for the Sigma 180mm f/3.5.

In the end everyone has to figure it out for themselves, what works for them.

[Gimbal]

My copy of the Samyang 135 is also, by far, the sharpest lens I have. It's as if it came from a totally new generation of lenses. it's even sharp in the corners, wide open. I like it.