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08-23-2013, 07:46 AM   #16
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QuoteOriginally posted by normhead Quote

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
That is surprising, and I will revise my previous statements about their consistency.

08-23-2013, 08:39 AM   #17
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The very low score for the DA15 tells me everything I need to know about the usefulness of their tests!
08-23-2013, 08:40 AM   #18
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QuoteOriginally posted by JinDesu Quote
That is surprising, and I will revise my previous statements about their consistency.
Isn't this simply because the K-5 has a strong AA filter?
08-23-2013, 08:43 AM   #19
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QuoteOriginally posted by gazonk Quote
Isn't this simply because the K-5 has a strong AA filter?
That may be, but I always thought the k-5 had the sharper sensor amongst the Sony, Pentax, and Nikon uses.

08-23-2013, 09:12 AM   #20
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QuoteOriginally posted by normhead Quote
Top performing Pentax lenses that they didn't test.
16 of arguably the best lenses available for Pentax were not tested.
Agreed. I despised the 18-135 at first until CRIS calibrated it along with my K5. Lens now performs flawlessly and in my opinion it is one of if not the best standard zoom one can have particularly on a WR body. (Lightweight, Great IQ, Quite AF, Ideal Range, excellent build and yes, WR). Perhaps they'll revise the article in the future with additional tested lenses.
08-23-2013, 09:55 AM   #21
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I'm surprised that there's no mention of the DA*50-135mm f/2.8...it's the best DA zoom ever, in my opinion.
08-23-2013, 09:57 AM   #22
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QuoteOriginally posted by yygomez Quote
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)
You must have missed my post above...



A lens tested on a D7000 does not test out the same way it does on K-5.

If you can find the same lens tested on the same camera, like the Sigma 16-50 and the Tamron 17-50, you can make a comparison...

ANother note... if it were the same lens, the CA would not be different on the Pentax mount and the Nikon mount.... most of the difference between these two ratings can probably written off to variations in the copies used, rather any real comparison between the two systems. ALways a problem with these lens testing sites. They refuse to test enough lenses to determine sample variation, and without a stat for variation within sample lenses of the same type.. statistically, they got nothing.

Last edited by normhead; 08-23-2013 at 10:09 AM.
08-23-2013, 09:57 AM   #23
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QuoteOriginally posted by HSV Quote
I'm surprised that there's no mention of the DA*50-135mm f/2.8...it's the best DA zoom ever, in my opinion.
Well to be fair they didn't review any of the 3 Amigos either.

08-24-2013, 01:00 AM   #24
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My take on this: Pentax is coming, DXO believes. I was actually positively surprised, given the obvious lack of Pentax lenses on DXO. It seems they realize this and intend to correct it. Why? Just to fill in the gaps? Or because they have been impressed by recent Pentax cameras and expect more to come?
08-24-2013, 06:09 AM   #25
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QuoteOriginally posted by normhead Quote
You must have missed my post above...



A lens tested on a D7000 does not test out the same way it does on K-5.

If you can find the same lens tested on the same camera, like the Sigma 16-50 and the Tamron 17-50, you can make a comparison...

ANother note... if it were the same lens, the CA would not be different on the Pentax mount and the Nikon mount.... most of the difference between these two ratings can probably written off to variations in the copies used, rather any real comparison between the two systems. ALways a problem with these lens testing sites. They refuse to test enough lenses to determine sample variation, and without a stat for variation within sample lenses of the same type.. statistically, they got nothing.
I didn't missed your post, I was just thanking the one that started this thread, and I still think the DXO test is a valuable piece of information if you know how to read it, of course there are variations from lens to lens
08-24-2013, 07:59 AM   #26
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QuoteOriginally posted by yygomez Quote
I didn't missed your post, I was just thanking the one that started this thread, and I still think the DXO test is a valuable piece of information if you know how to read it, of course there are variations from lens to lens
I agree with you there, if you are considering two non Pentax lenses and you can find them tested on the same camera body, it can be enlightening.. like when I was deciding between the Sigma 16-50 and Tamron 17-50. HOwever the best use of DxO is to start at the top of their lens ratings and see how the lens you are considering rates on every system. If it receives high marks on 3 or 4 camera bodies you can assume it is consistently a high performer. With Pentax lenses that doesn't work. They have not tested enough 3rd party lenses on Pentax to even help you guess which lenses might excel.

This Sigma 35 1.4 DxO loves so much is one of the first. ANd as I said, it tested 4 points lower on a a K-5 than it did on a D7000, two cameras that use the same sensor. So, that's a bad start.

Once they've tested the Tamron 17-50, Sigma, 70 , so we can do some direct comparison with some Pentax lenses we might be able to have a better guess as to how the Pentax lenses stack up against offerings from other companies. But right now there really isn't a very clear picture of how this operates.

For example, Imagine Resource rates a D7000 at 2100 lw/ph a K-5 II tests out at 2200 yet DxO rates the D7000 35 1.4 image higher... see what I'm saying. IR shows me the images so I understand how they come by their data, DxO doesn't. But their numbers show a D7000 image rated at 26 and on a Pentax rated at 22. That means the D7000 image is almost 18% better. Not so at IR where the Pentax image is 6% better.

Until you can resolve these discrepancies, and I'm not even going to hazard a guess who's right, there has to be a legitimate expression of doubt when interpreting any of these comparisons. They provide you information... but not enough you can draw any solid conclusions without inspection of images on line. After all, you want a lens that suits your style... and paper ratings don't begin to address that. Some of us like warmer images, some of us like the colour of Pentax glass, and CA and MTF don't matter to us. As much as these sites like you to think they are experts... you're the only expert on what you like to shoot. DxO has said, the Sigma 35 1.4 is pretty much the best lens for any system... but it doesn't have a lot of popularity on the forum... there might be a reason for that that DxO's numbers don't address. If you examine this lens and a few others and decide their rating system suits your style, then believe their numbers... personally, my experience with them has been that to a point they're good, but they can't help you decide whether to buy the Tamron 90 of DA 100 WR, because they haven't done the head to head tests... until they have done direct comparisons on the same camera body with the full run of lenses available to Pentax, there headline should read " Of the lenses we've tested for Pentax, which excludes many of the best, this is what we found was the best." They're lack for integrity in disclosing their paltry testing effort tends to make me want to ignore them altogether. Their information simply isn't reliable to the casual reader, and is misrepresented. That is a testament to the character of those running the site.

I can't recommend them. If you want more reliable data, go to Imagine resources, a much more comprehensive and reliable outfit, IMHO. They aren't perfect, but they try their best and don't try and hide the limitations of their research. DxO is interesting as second or third opinion, it's interesting to see what they think, but the thing that stands out for me is the inconsistency of their rating process. In the end, you can read the whole site, and still not understand how their rating system works, or more importantly... what it means to you.

Last edited by normhead; 08-24-2013 at 08:29 AM.
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