Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-15-2009, 11:33 PM   #1
Senior Member




Join Date: Feb 2009
Location: Lévis, Canada (Québec)
Posts: 143
K-7 RAW samples tested at home...

Hi,

I did some tests with the RAW (DNG) samples of a pre-production K-7 provided by Imaging-Resource (ISO 1600 to 6400 with NR off), converting them with CaptureOne Pro 4.8.1 and Lightroom 1.3.1 (I haven't updated to LR v.2 yet) and I thought I'd share my observations on the forum.

All were converted in DNG file format and compared ot the original DNG RAW samples for analysis.

First thing I see is that Lightroom has better color accuracy than CaptureOne, something that doesn't surprise me. The DNG format was created by Adode, so I would expect a software made by Adobe to perform very well on such a matter.

(Converting a K-7 PEF file might be a different story, though. When converting my K10D PEF files, I usually have better color accuracy by using CaptureOne. The K-7 might behave in a similar or completly different way.)

Beyond color accuracy, I found that CaptureOne does a better job at reducing the chroma noise present in the pictures than Lightroom does. I couldn't see much difference once the slider was beyond 25 on the chroma noise reduction scale in Lightroom. On the other hand, I was able to push the chroma noise reduction slider up to 75 in CaptureOne, something I am unable to do with my K10D (I would never push the slider past 55).

Please note that all the conversions were done with the sharpening set at 0, in order to keep demosaicing artifacts down to the minimum.

As I expected, CaptureOne was able to produce more detail than Lightroom, probably because of its algorithm, designed specifically with digital backs in mind. (Usually, the more the pixels, the less the sharpening artifacts are visible — just compare a 2 Mpix and a 10 Mpix picture after applying an unsharp mask at 50%, radius 5 in Photoshop and you'll see what I mean, lol.)

There are more demosaicing artifacts visible with CaptureOne, however, especially at ISO 1600. The difference is less obvious at ISO 3200 and more so at ISO 6400.

Anyway, both show lots of luminance noise (and resulting noise artifacts) which can only be tamed by reducing the detail level through luminance NR. I'd rather have higher luma noise and higher detail level than little noise and little detail, but I wish the luma noise of the K-7 was a bit lower. (Pushing the in-camera NR up might do the trick.)

As a side note, I must mention that the ISO 1600 sample converted by CaptureOne produced some very large post-processing hot pixels-like artifacts.

I guess it figures out somehow, since CaptureOne hasn't been updated to support the K-7 yet. Same goes for Lightroom 1.3.1, which doesn't support the K-7 at this point (not sure about Lightroom 2.4, though).

While it's impossible to draw a final conlusion based on the samples of a pre-production model (and converted with software that does not fully support the camera yet), the results I got are quite interesting at this point.

With noise reduction off, the K-7 RAW files are quite capable of delivering a very high level of detail (with good glass, that is), at the expense of a higher luminance noise level and more intrusive demosaicing artifacts. In fact, the level of detail at ISO 1600 is high enough to use a bit luminance NR without fear of smearing, IMHO.

It might be another story with the in-camera NR on, but I suspect that the low and the medium settings will provide a fair balance between detail level and luminance noise smearing. The Imaging-Resource samples seems to confirm that, at least at first glance.

I'll do some further testing with the other ISO 1600 to 6400 samples, in order to measure the efficiency of the in-camera NR (low, medium and high NR) compared to the out-of-camera software NR. More on that in an update later.

I dont want to get in trouble by posting images that are copyright protected, so I can't show you with any crop or example... But you can download the samples from their website here and do your own tests to see if my conclusions are sound and fair (or biased and pointless, lol).

BTW, has anyone done similar tests using other (or identical) RAW converters? If so, what were your findings?

...

07-20-2009, 02:01 AM   #2
Senior Member




Join Date: Feb 2009
Location: Lévis, Canada (Québec)
Posts: 143
Original Poster
Update, as samples with Noise Reduction were also tested.

My first impressions are that the Pentax NR affects chroma noise much more than luminance noise. In all cases, I found out that the high setting starts to really affect color accuracy and is best avoided.

The level of detail is reduced when applying a high NR, which is a sign that luminance NR starts to kick in much more at that setting.

Otherwise, I'd say the low level shows slight improvement on chroma noise over the NR off setting, with only minor loss of detail. The med level is a fair compromise, with some detail loss, but also a bit less visible chroma noise and luma noise as well.

As stated above, the high NR setting is just too agressive in reducing luminance, smudging away a bit too much detail, at least IMHO.

The demosaicing artifacts are still very visible at all settings (none, low, medium, high) and obviously increase as ISO does.

Lightroom did a better job of retaining color accuracy at high ISO regardless of the NR setting. But CaptureOne still manages to pull out a bit more detail than Lightroom, but only marginally so, as the detail gets lost in the increasing noise. Except in emergency situations, my opinion is that ISO 6400 is almost useless, even with NR turned off and the picture converted to B&W.

So far, the K-7's noise levels seem quite improved over those of the K10D (at ISO 1600), but this comes with much more noise artifacts as well. Such artifacts could be the result of a bad demosaicing job done by the RAW converter, as neither Lightroom 1.3 nor Capture 4.8 support the K-7 at this moment.

But nonetheless, although very good, the K-7 is far from being a revolution on noise levels when compared to the K10D, so much that I've decided to cancel my K-7 order and wait a bit before committing into buying the new Pentax flagship. I'll weight the pros and the cons a bit more until I know if it's worth it to upgrade.

If I choose not to upgrade, I might as well spend the money into more Pentax glass, which should prove very useful when I finally upgrade the body as well.

07-21-2009, 07:24 AM   #3
Inactive Account




Join Date: Oct 2007
Location: Massachusetts
Posts: 6
Your test is a bit meaningless...

Thanks for posting your findings, but they have essentially no value. Neither program you've tested the files with even supports the k-7. You're taking a new camera and testing it with old, now second-rate software that doesn't have a chance of competing with up-to-date software that carries the k-7 profile.

I think it's a little comical, actually.

If you aren't willing to shell out the money for the newer version of ACR then yes, I agree, the k-7 isn't for you.
07-24-2009, 05:04 PM   #4
Senior Member




Join Date: Feb 2009
Location: Lévis, Canada (Québec)
Posts: 143
Original Poster
QuoteOriginally posted by chrswggl Quote
Thanks for posting your findings, but they have essentially no value. Neither program you've tested the files with even supports the k-7. You're taking a new camera and testing it with old, now second-rate software that doesn't have a chance of competing with up-to-date software that carries the k-7 profile.

I think it's a little comical, actually.

If you aren't willing to shell out the money for the newer version of ACR then yes, I agree, the k-7 isn't for you.
It's not so much a question of money, since ACR is free to update provided you have a recent version of Photoshop or Lightroom. I could probably afford Lightroom 2, which I would need in order to upgrade to ACR 5.4, since Lightroom 1 doesn't support such a recent version of ACR (last supported version is ACR 4.1).

But fact is, I'm not about to upgrade to Lightroom 2 yet, as I use it only as an alternative software when CaptureOne Pro doesn't give me the results I'm looking for. C1 is a lot better than LR when it comes to detail level and sharpening (IMHO), so I only use LR when I do a lot of individual color adjustments (that's where LR shines, much more than C1).

(Sure it's only 200$ in US funds to upgrade from Lightroom 1.3 to 2.4, but I'd rather use that money to run my business, at least at this point in time. That's 200$ I'd better spend on my phone bills and marketing expenses.)

But upgrade issues aside, I've only done the test to share my impressions about the high ISO performance of the K-7. That's what forums are for, aren't they? Share infos, comments, questions, etc!

With the compatibility of the software used out of the equation, my conclusions are that the noise levels show some improvement over those of the K10D and that the level of detail the K-7 manages to keep is excellent when compared to my old K10D (at least at ISO 1600, since the K10D doesn't get beyond that).

And while there are a bit too much artifacts showing here and there to my taste (which might probably much be less of an issue with an upgraded RAW converter — I hope C1 4.8.2 will be available soon), my K10D isn't free of such problems anyway.

It's just that I was expecting more improvement, probably too much in fact. Pixel-peeping is making photographers more and more demanding and when expectations are too high, they aren't met. Such is the case for me, but not because the camera isn't

But the K-7 is much more than just high ISO performance. It also means much better metering than the previous K bodies (I saw P-TTL flash shots comparasion between the K20D and the K-7 and the difference is amazing), faster AF (seems it's the biggest improvement over the K20D) and lots of nice features you can't find anywhere else in the same package.

So I'm not pulling the K-7 out of the equation yet, since going full frame would be much more expensive and switching from a Pentax APS-C to a Canikon APS-C is just pointless when you have already good Pentax glass at hand.

I'll just going to ponder a bit more on the advantages of upgrading to the K-7 (more responsive, more accurate camera) compared to getting new glass (better long term investment). I have my eyes set on the FA31, DA21 and DA*55... and maybe the DA*16-50 as well (if only for the weather seals).

Cheers,

07-24-2009, 06:39 PM   #5
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,576
Try Raw Developer. You can get a demo, and it supports the K7. I found it to better handle the K7 dng file than Aperture (which doesn't have a K7 profile). Plus in general I find RD to give the best detail. I hate the interface of C1...
07-24-2009, 07:05 PM   #6
Senior Member




Join Date: Feb 2009
Location: Lévis, Canada (Québec)
Posts: 143
Original Poster
QuoteOriginally posted by nostatic Quote
Try Raw Developer. You can get a demo, and it supports the K7. I found it to better handle the K7 dng file than Aperture (which doesn't have a K7 profile). Plus in general I find RD to give the best detail. I hate the interface of C1...


Strange, I get a lot of people telling me how they don't like C1's interface. I really like it, though. Guess it's a metter of taste.

Thank you for the info: I thought Raw Developper was only Windows-compatible. Looks like you found a good RAW developper, there. I'll experiment with it soon.

Cheers,
07-28-2009, 06:51 PM   #7
Senior Member




Join Date: Feb 2009
Location: Lévis, Canada (Québec)
Posts: 143
Original Poster
Tried Raw Developper and the difference is noticeable.

Although noise levels are similar (and not really good at ISO 6400, as one might expect), the artifacts seen when using Lightroom 1.3 and CaptureOne 4.8 are much, much less an issue.

I'll wait until CaptureOne is updated before I draw some conclusions on the K-7 high ISO quality.

But so far, it seems it is better than I expected when converted from RAW using a supported developper. ISO 1600 is very clean, with almost no chroma noise and ISO 3200 is still acceptable.

Looks like a good upgrade (and improvement) from my K10D, that's for sure, especially with the better AF and metering.

And with better metering, I'll have more properly exposed shots, instead of underexposed and over-exposed shots that I need to correct with an EV adjustment that affects noise further more.

Still, a new FA 31mm F/1.8 Limited (or DA*55mm F/1.4, DA*50-135mm F/2.8, etc) is almost as tempting. But with the K10D's inaccurate AF, it's not worth it. The K-7 could be a better investment after all.

Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
artifacts, camera, captureone, detail, dslr, iso, k-7, level, lightroom, noise, nr, photography, samples
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K-5 vs D700 - ISO6400 RAW, Testing w/samples... JohnBee Pentax News and Rumors 62 10-04-2010 10:22 AM
Shooting Raw Gemstones or Mineral Samples brecklundin Photographic Technique 9 12-03-2009 05:45 AM
K-7: Any Pentaxian who tested the camera with a TC? Pentaxor Pentax DSLR Discussion 1 07-06-2009 01:28 AM
Photo of the Day - Home Sweet Home Adam Post Your Photos! 1 07-02-2009 01:18 PM
Tested 50mm FA/1.4 vs A1.7 Michael Barker Pentax SLR Lens Discussion 0 09-20-2008 07:48 PM



All times are GMT -7. The time now is 03:14 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top