[NickLarsson]

Not sure if it has been already posted or not:

DxOMark - Best lenses for your Pentax K50: Pentax lens overview

[normhead]

That's a pretty much useless review.... because of the lenses not included. Lenses they didn't test, that I use, the the Sigma 8-16, Sigma 70 macro, the Tamron 90 macro, the DA* 60-250, the DA 18-135. Neither does it mention the 31 ltd, the 43 ltd, the 77 ltd, the DA*200 or the DA*300 As far as I'm concerned if you talk about the "best lenses for a K-50" and don't include the first three, you're just wasting everyone's time and actually doing a disservice to your readers. I suspect that DxO didn't rate the Sigma 70 and Tamron 90 because they are much higher rated on other systems and they don't want to have to explain that all over again. Most people would think, well a lens is a lens, when in fact the same lens has much different ratings on DxO depending on which system it's on, and despite the high scores in DxO sensor ratings, lenses rate very poorly when evaluated on Pentax systems. Nevertheless, IR uses the SIgma 70 for it's resolution tests so you can compare how different systems do with the same lens, something that's nice to know. DxO pretty much hides that kind of information.

The title of this article should be " We didn't test most of the lenses commonly considered to be the best lenses available for the K-50, but of the cheapies we did test... these are the best."

Personally I did a lot of research before I bought each lens, and looked at a lot of pictures. I'd put my group of lenses up against DxO's any day, I will have better results than they do and have a better collection of lenses. It's sad when a company that wants to make money providing a service doesn't even meet the level of understanding of many of the users of the camera when making this kind of recommendation. I hope no newbies read this crap.

[JinDesu]

The top 3 in each category:

Best prime -
Sigma 35 F1.4
Pentax DA*55 F1.4
Pentax DA 50 F1.8

Best zoom -
Pentax DA 16-45 F4
Pentax DA*16-50 F2.8 (<-heh)
Pentax DA 12-24 F4
*Honorary mention: 4th place - DA 18-55 F3.5-5.6 II

Best portrait lens -
DA*55 F1.4
DA 50 F1.8
DA 70 F2.4 Ltd

Best Standard zoom - See Best zoom

Best Superzoom -
DA 55-300 F4-5.8
DA 18-250 F3.5-5.6
Sigma 18-200 F3.5-6.3 II DC OS HSM

I suspect that DxO didn't rate the Sigma 70 and Tamron 90 because they are much higher rated on other systems and they don't want to have to explain that all over again.

Tamron 90 F2.8 Di Macro on D7000: Score is 18 (no available score for Pentax)
Sharpness: 8MP
Transmission: 3.2TStop
Distortion: 0%
Vignetting: -0.4EV
Chromatic Aberration: 9 micrometers

Sigma 70 F2.8 Macro on D7000: Score is 19 (no available score for Pentax)
Sharpness: 8MP
Transmission: 3.1TStop
Distortion: 0%
Vignetting: -0.4EV
Chromatic Aberration: 12 micrometers

So they probably didn't include those two because they didn't test the Pentax k-mount versions, but to extrapolate from the D7000 results, they would score lower than the top 3 primes.

For example:

DA*55 F1.4 on Pentax k-50: Score is 23
Sharpness: 9MP
Transmission: 1.7TStop
Distortion: 0.2%
Vignetting: -0.8EV
Chromatic Aberration: 8 micrometers

Best aperture: F2 (not best sharpness aperture, best aperture for everything above combined)

Admittedly, I don't put much stock into what DXOmark says. But per their methods, the lenses that they list make sense. And if a lens isn't on Pentax mount, just select the Nikon D7000 and you'll see the relative performance.

[K57XR]

What happened to the DA18-135WR - didn't make the list?

[Docrwm]

Thanks. One of the surprise performers is the 50/1.8. It seems to be the Best Buy among primes given performance/price. The old 55-300 does very well too and gets high price/performance marks too. Too bad they didn't include the 18-135.

[JinDesu]

What happened to the DA18-135WR - didn't make the list?

Thanks. One of the surprise performers is the 50/1.8. It seems to be the Best Buy among primes given performance/price. The old 55-300 does very well too and gets high price/performance marks too. Too bad they didn't include the 18-135.

DxOMark - Pentax smc DA 18-135mm F3.5-5.6ED AL [IF] DC WR

Unfortunately they did not appear to have reviewed the 18-135 yet.

[Rondec]

DXO mark scores are mostly about light transmission and a little bit about resolving power. I don't feel like they really tell you what you need to know when choosing a lens, but I guess if someone is about accumulating lenses with a high DXO score, then that is great.

[Docrwm]

DXO mark scores are mostly about light transmission and a little bit about resolving power. I don't feel like they really tell you what you need to know when choosing a lens, but I guess if someone is about accumulating lenses with a high DXO score, then that is great.

No, it's not the whole story- but another piece of information upon which to base decisions.

[6BQ5]

All publicity is good publicity. If that article helps promote Pentax products then I'm all for it!

[JinDesu]

Alternatively, looking through the wealth of information in the tabs (sharpness graphs, etc) for each lens can help decide also - if you are into that kind of thing.

Imaging Resources isn't without fault either. Their comparometer tool tends to select noise reduced images for comparison from certain cameras - When I compared the 5DMk3 vs the k-5 a while back, I was like, how the hell is the 5DMk3 so clean?

Then I realized they were showing me noise reduced pictures vs no-noise reduction on the k-5. You actually have to go into each camera's page to find the proper images for comparison.

[seventysixersfan]

I was surprised how well the DA 16-45mm scored. Might have to acquire that zoom sometime...

[JinDesu]

I was surprised how well the DA 16-45mm scored. Might have to acquire that zoom sometime...

DA 16-45 F4 (Best at 28mm F4)
Sharpness: 8MP
Transmission: 4.2TStop
Distortion: 0.3%
Vignetting: -0.8EV
Chromatic Aberration: 17 micrometers

DA*16-50 F2.8 (Best at 35mm F5.6)
Sharpness: 9MP
Transmission: 3.1TStop
Distortion: 0.4%
Vignetting: -0.9EV
Chromatic Aberration: 18 micrometers

Looking at the individual numbers, the DA*16-50 is sharper and transmits more light. Of course, you will need to really go into the individual tabs of each lens to compare why the DA16-45 scored higher, but I think DXO also weighs the "Best at ##aperture" for lower aperture results.

[Docrwm]

DA 16-45 F4 (Best at 28mm F4)
Sharpness: 8MP
Transmission: 4.2TStop
Distortion: 0.3%
Vignetting: -0.8EV
Chromatic Aberration: 17 micrometers

DA*16-50 F2.8 (Best at 35mm F5.6)
Sharpness: 9MP
Transmission: 3.1TStop
Distortion: 0.4%
Vignetting: -0.9EV
Chromatic Aberration: 18 micrometers

Looking at the individual numbers, the DA*16-50 is sharper and transmits more light. Of course, you will need to really go into the individual tabs of each lens to compare why the DA16-45 scored higher, but I think DXO also weighs the "Best at ##aperture" for lower aperture results.

Price may also play a role, as can the inherient unreliability of the SDM in the 16-50.

[normhead]

What happened to the DA18-135WR - didn't make the list?

Top performing Pentax lenses that they didn't test.

Tamron 17-50, 90 Macro,
Sigma 8-16, 70-200, 70 macro- 105 macro, 85 1.4, 300, 500
Pentax 31, 43 and 77 limited, DA 18-135, DA* 200, DA* 300, and a whole host of legacy glass.

16 of arguably the best lenses available for Pentax were not tested. Throw in the Samyang lenses which are top rated on DxO on every system they test on, but not tested on Pentax at all, and you could make a case that the best 20 lenses available for K-mount aren't even included in their list. I seriously question the compiler of this list, and once again warn people not to pay any attention to DxO until you've done enough reading on the site to understand their biases and omissions. It's not that their information is useless. It's that you really have to pay attention to understand what it means.

Personally I won't take them seriously until I see the Sigma 70, 85, 105 and 70-200, Tamron 17-50, 24-70 and 90 macro, all Samyangs, and the 18-135, 60-250 , 200 and 300 tested on their site on K-mount. You simply cannot take a site seriously that tests all those lenses (but the DA lenses) on Canon and Nikon, but not on Pentax. They have a serious anti- Pentax bias in their research. They are a private company and it's all market driven, and Pentax has really small market share, I understand that, but fair is fair. My advice to them with regard to Pentax would be walk the walk, or shut up.

Unless what Pentax users were supposed to get from that would be that the Sigma 35 1.4 is a really good lens. How does it stack up against the FA 31? DxO doesn't know, even though they try and sound like "experts".

Admittedly, I don't put much stock into what DXOmark says. But per their methods, the lenses that they list make sense. And if a lens isn't on Pentax mount, just select the Nikon D7000 and you'll see the relative performance.

Not exactly...




The 35 1.4 tests 4 points lower on a K-5 than it does on a D7000, even though the K5 has a higher sensor rating (go figure). DxO numbers are pretty inconsistent comparing different brands... they really only make sense comparing the same body

[yygomez]

Thanks for posting! even though they did not test many lenses that we would like to see I think it is a great piece of info, for example I was able to compare the DA 16-50 with the sigma 17-50 (on Nikon D7000 the same sensor resolution)