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03-01-2015, 09:00 PM   #16
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QuoteOriginally posted by UncleVanya Quote
It is always hard to switch systems - I have a small superzoom fixed lens Nikon that I didn't find too complex. I hate Canon's interface on the other hand... LOL.
Thank the stars Sony redid their ergonomics with the A500, otherwise I might still be there watching the A mount starve and I wouldn't have met all the nice people here!

03-01-2015, 10:14 PM   #17
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Despite the sensor size (which kills low light performance) on their cameras, Panasonic really does make nice stuff. I have a Lumix LZ8 Point and shoot and it's pretty straightforward and packed with features for what it is. Plus they have the marketing capital to back their products up. Keep in mind that they're also a major player in the consumer electronics division and very well known.

Given that, it's no wonder they can withstand poor marks on dXo. But I will say that the Venus engine in their cameras is a monster for colors, it's highly impressive.
03-01-2015, 10:54 PM   #18
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Pentax used to have higher ratings, but Sony barfed out a bunch of cameras in the past 1.5 years, pushing Pentax down a bit, and then Nikon released some too.

The real mystery is why they don't bother testing the 645Z. They tested the 645D and it got a respectable score. They also tested a Phase One camera.

DxO Mark's website is just the worst by the way. It's so clunky and unintuitive. Their methodology is also a little weird in the way they come up with values based on the sensor + lens combo. We don't have to worry about the general public using their info to make camera purchasing decisions because the general public won't be able to make sense of anything on that site.
03-01-2015, 11:06 PM   #19
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Ah ah, in my opinion, it's better to refer to tests rather than subjective judgement. I take DXO as a good reference.
There is no Pentax sensor. The sensors used by Pentax are from third parties, for instance Sony Semiconductors , who also sell sensor to Nikon and other brands.
And Nikon have a trick: the Nikon D7100 uses lower actual ISO than Pentax. So with a D7100 @ ISO400, you'll get better IQ than Pentax K-3 @ ISO400, but the shutter speed of the Nikon will be slower.
Having lower actual ISO is not a good thing, so Pentax has not done this trick. However, Pentax could have added a ISO80 on the K-3 as they did on the K-5.

03-01-2015, 11:08 PM - 1 Like   #20
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Within the APS-C segment, all the current Pentax cameras are toward the higher end of the spectrum.

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03-02-2015, 12:24 AM   #21
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QuoteOriginally posted by brewmaster15 Quote
Camera Sensor Ratings by DxOMark - DxOMark

Seems our Pentax sensors didnt come up high on this listing..

Just how accurate do you guys think these reviews are?

its a tad discouraging to see things like thison websites..makes it hard to attract others to use pentax.

Al
In this table K-3 is rated below K-5 and K-5II. My experience says something quite different.
03-02-2015, 01:10 AM   #22
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QuoteOriginally posted by Obin Robinson Quote
Even if it was twice the price I'd buy the Pentax over the Nikon. I can't stand that horrible Nikon user interface. We have one at work and I find the ergonomics and interface to be very un-ergonomic. obin
same problem here, i have the D500 and D5200 at work i sometimes need them to do technical (R&D) pictures or pictures of the new hires.... somebody bought the Nikons and i always struggle with the menu.... many times I brought my loved K-5 or nowadays the K-3 to be quicker...:-)
03-02-2015, 03:18 AM   #23
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QuoteOriginally posted by normhead Quote
In DxO ratings, the low light performance count for a lot. SO with few really fast Pentax lenses they tend to punished for that. Less than stop of difference in low light performance really skews DxO marks. Ver few lenses that aren't 1.4 or better are top rated, again because of the low light thing.
I don't look at DXO ratings. I look at measurements.

03-02-2015, 03:36 AM - 1 Like   #24
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QuoteOriginally posted by HYS Quote
In this table K-3 is rated below K-5 and K-5II. My experience says something quite different.
The DXO Mark sensor score does not include resolution as a factor. It is assumed that you will factor that in as well. The difference of two points is primarily due to the dynamic range difference, because the K5 has iso 80 and the K3 doesn't. Otherwise the sensors are very comparable, but with the K3 having better resolution.

One problem I do see is that DXO Mark doesn't factor quality of noise (presence of banding) into their equation. The D7100 (and in the past many Canon cameras) is prone to banding and is much less usable at high iso than the K3, even if it scores a little better in the sports iso score.
03-02-2015, 09:40 AM   #25
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The DxO ratings are pretty arbitrary. For instance, the D7100/5200 Toshiba sensor has a shadows banding problem (much like the Samyang sensors did); Nikon has dropped those sensors accordingly, but DxO scores them on top. Pretty much everyone here who uses the D7100 and K-3 solidly favor the IQ and low-light capabilities of the K-3.

As a studio camera, the 645D clearly beats out any of the FF cameras by a wide margin, but as Norm points out the emphasis on low light capabilities are weighted heavily in the final scoring. If the 645z was rated (it will never happen, you can be sure), certain very important players would be very unhappy with the results - and DxO wants to keep those potential customers as happy as possible.

Regarding those certain players, I transitioned from a Canon FF to a Pentax body that was down-rated very publicly by DxO for smoothing at high ISO. Well, that Canon body did a heck of a lot more smoothing (yes, in RAW) than my Pentax, but never has smoothing been found on the Canon and Nikon bodies. Well, all modern bodies smooth in the higher ISOs (Pentax could hide it better by implementing the smoothing more gradually).

As others have mentioned, scores less than 5 points apart amount to very little more than rounding error. I do like the ability to compare much older sensors with comparable newer designs. For instance, the old 6mp sensors on APS-c bodies are roughly comparable to the original Q (at least in good light) - and the scores are accordingly comparable.

Finally, nothing about the sensor ratings are absolute - even when all the factors are weighed. Some perform a bit better in good light, or have a bit more dynamic range, others might be better in low light. The ratings help with those determinations. There are different ways to get the most of a sensor. Many people feel strongly that the 16mp sensor cameras are tad better than the K-3 in low light. When I use LR for conversions, I completely agree that around 3200, the 16mp sensors appear to have about a one-third stop of an advantage. However, if you use a more sophisticated converter - such as Capture One - you can manipulate micro-sharpening to allow for greater noise reduction. In that scenario, the additional acuity of the K-3 comes through and it easily outperforms the 16mp sensors. The process requires a bit more work, but the results are better.
03-02-2015, 10:08 AM   #26
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QuoteOriginally posted by biz-engineer Quote
I don't look at DXO ratings. I look at measurements.
I don't look at measurements, I look at pictures.


If you want to know what kinds of picture a camera takes, why would you look at measurements?

But, let's make use of measurements, as an engineer, you should know.. what use is a measurement, without a margin of error, a standard deviation, and a calculation that includes a sample variation factor for the cameras and lenses tested?

Now to that one, I actually know the answer... very little.
03-02-2015, 10:28 AM   #27
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Just for grins, Norm, what do you think should be the minimum sample size (i.e. numbers of different copies of a camera body / lens tested) and minimum number of independent iterations of the test routine for each one before DXO would have a mathematically valid sample size from which to draw its conclusions?
QuoteOriginally posted by normhead Quote
I don't look at measurements, I look at pictures.


If you want to know what kinds of picture a camera takes, why would you look at measurements?

But, let's make use of measurements, as an engineer, you should know.. what use is a measurement, without a margin of error, a standard deviation, and a calculation that includes a sample variation factor for the cameras and lenses tested?

Now to that one, I actually know the answer... very little.
03-02-2015, 10:37 AM   #28
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The single number 'Sensor Score' should usually be ignored- it's distilled from their other measurements into one easily digestible number and may or may not represent usage that applies to you.

If they didn't have "Sensor Score" or the various "Sports/Landscape/Portrait Scores" we'd instead have threads about people complaining that looking at the DxO measurement graphs hurts their heads.

About 'normalizing' the scores based on sensor area...when you do look at the more detailed reports about the cameras, they do give "Print" and "Screen" versions, which let you essentially compare the same output size between cameras or how they perform at the 'pixel level' for you 100% crop viewers. If you really care how it does per unit area of the sensor, you could probably interpolate using either version knowing the pixel density or sensor size.


And while Norm's complaining about sample size- anyone out there with multiple copies of the same body notice sample variation between sensors? This is a sincere question. We know lenses can vary somewhat from copy to copy, but how about noise characteristics across copies of the same body?
03-02-2015, 10:49 AM   #29
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QuoteOriginally posted by monochrome Quote
Just for grins, Norm, what do you think should be the minimum sample size (i.e. numbers of different copies of a camera body / lens tested) and minimum number of independent iterations of the test routine for each one before DXO would have a mathematically valid sample size from which to draw its conclusions?
Someone with a background in statistics could probably come up with something. Just looking at the stuff lens rentals posts, I would think a 20-25 lens sample would be a minimum. Tested on at least 10 bodies....

Or long story short, while everyone wants conclusions, no one wants to pay to have someone actually do meaningful tests. Obviously having a few tests with some data, however unreliable is better than having no tests and just making it up with random impressions, as most reviewers do, but in this case, one has to realize that the data as presented is extremely unreliable. Made worse by the fact that when checked, the info from these sites lack internal reliability. A higher rated camera body with a higher rated lens can have poorer results than a lower rated camera body with the same lens on a different mount. That kind of aberration doesn't happen when you have good numbers. The value of these numbers are pretty clear if you studied them. They are better than guess work, but less than reliable.

On the other hand if you're looking at one system, where all the lenses were tested on the same body, like on Photozone, you can definitely say the copy or the 31 ltd Klaus tested on the K-10 was better than the kit lens. It's true for the copy he tested of each lens. It's when you start trying to extrapolate to different bodies and lenses from different manufacturers it all goes out the window etc. then the info just isn't that good.

SO in essence, if you tested a 31 ltd and a Sigma 30 1.4 and one was better, some one else could do the same test with their 31 and their 30 and their K-3, and get different results. it's happened right here on the forum.

Just for a grin.

Last edited by normhead; 03-02-2015 at 10:59 AM.
03-02-2015, 11:45 AM   #30
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like normhead and Monochrome, I don't like measurements from the light meter of my K-3 because they are subject to errors due the temperature variations, humidity of air, battery voltage and manufacturing process uncertainty etc. So, (measurements are rubbish , we should not consider them) I do light metering with my eyes and determine exposure time, f stop and iso by subjective guessing.
And you know what? It works!

Last edited by biz-engineer; 03-02-2015 at 12:18 PM.
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