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03-23-2009, 11:56 AM   #1
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K20D Noise?

Hi, I got an K20D as an replacement for my K10D that pentax took back, the problem is that this new K20D I got works even worse than my old K10D

More about the other problems later, first of all, it makes images blue in the lower border on higher iso, depending on object it shows more or less.
To show this I made an video with some samples that I put up on youtube.

YouTube - Pentax K20D Noise

To make matters worse, it also front focuses some milimeters and behaves very wierd.
I sent it in for service some weeks ago and all I got was a paper with tips of settings like "Auto-ISO" which made me very angry beacause I have studied photography for 2 years and been photographing with d-slr´s for about 5 years, the only regret I have is that I chosed pentax over canon or nikon

So please Pentaxforums, is this a common experince of pentax or do I just have bad luck?
Sorry for my english btw, hope you understand me anyway

Best Regards Henrik

03-23-2009, 12:00 PM   #2
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The noise is not very much. I think this is normal for the K20d. When I compare this to a Canon 450d or the nikon d90/d60 there's no big difference.

The front focus can be changed inside the camera. I don't know exactly how, but you can find it in your manual.
03-23-2009, 12:13 PM   #3
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What kind of lighting is that?
If it's fluorescent, I think it might be picking up the tube fluctuations...
Repeat the test in sunlight, moonlight or another light source...
03-23-2009, 12:15 PM   #4
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QuoteOriginally posted by kenyee Quote
What kind of lighting is that?
If it's fluorescent, I think it might be picking up the tube fluctuations...
Repeat the test in sunlight, moonlight or another light source...
was just going to say that...saw another thread where someone was getting a yellow tint in their kitchen; had to do with the shutter speed and the refresh rate of the fluorescent lights...

03-23-2009, 12:39 PM   #5
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The lightning source is incandescent(?) I have tested in sunlight and it gives a more red tone in the bottom border.
The noise that bothers me is the coloured noise in the bottom and top of the frame, haven't seen this behavior on any other camera :S
03-23-2009, 03:36 PM   #6
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I'm not sure what you expected at ISO 6400, but it's pretty normal for contrast and color to get flaky at the extremes of ISO on any camera. Those results could be improved with decent PP, and I'm sure different lighting would produce different results too.
03-23-2009, 06:03 PM   #7
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Agreed, I'm quite sure any photography I do in 6400 ISO will have to be in black n white. Concerts, etc..
03-23-2009, 06:11 PM   #8
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My K20D does the same thing. It can be minimized with a proper exposure. What does your histogram look like for the example images? I find that shooting RAW and exposing to the right a bit will help a good deal in high ISO situations.

03-24-2009, 07:31 AM   #9
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Hi Henrik,

The K20D tends to have more noise in the blue above ISO 1600, and at ISO 6400 you will be getting lots of blue noise (and it isn't just in the bottom edge, but everywhere you have darker neutral tones). Other comparably-priced cameras have different noise profiles (Nikons go greenish) but also combat noise with heavy noise reduction. At the default settings, the K20D will do relatively light NR to preserve detail which these other cameras turn to mush at ISO 6400.

Personally, I reduce noise in three steps:
- In camera, by setting NR to "weak"
- Processing the raw file (the large chomatic noise, esp)
- By combining multiple high-ISO shots at the same exposure with Enfuse (read about it here).

Of course, you could also spend 3x as much (plus more for nice, stabilized lenses) and get a very low-noise at high-ISO camera, but that is up to you and your bank. ;-)

-Mark
03-24-2009, 08:17 AM   #10
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Well, mine also show this tendency to purple coloring on top and bottom, right from iso 1600, but it's quite discreet, not like what you've got here (a blue 3200iso shoot? What the ???)...
This can also be seen better in pics taken with the cap on, and is not dependent on shutter speed, so it's not noise building (it's the same at 1/4000 and 30").
I guess it's a problem with the black pixels substraction, or something like that... I bet that there is something generating heat next to the CMOS top and bottom, making those rows slightly more purple...

BF/FF is easily fixed by using the AF adjust menu.
03-25-2009, 12:14 AM   #11
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It seems to me this issue of noise is one of the most misunderstood issues with Pentax cameras. I do not know how anyone would come to Pentax, without first having learned about Pentax' unique handling of noise.

The K20's difference in noise is more related to its "hands-off" philosophy than it is to the competition's better performance. The K20 shows more noise in its images ( as well as more detail) at default because the K20 provides the user with the freedom to strike the delicate balance between noise and detail for him/herself. It is that simple! The K20 is performing on a par with the competition in terms of noise, particularly when you consider the sensor size to MP ratio.

Pentax should be applauded for taking such a daring approach to the issue of noise because it demands a more educated and autonomous user. Educated and autonomous users are not the majority of buyers--one need consider this for a moment, me thinks. Even DPreview, not known as Pentax fanboys by the stretch of anyone's imagination, acknowledges this fact in its K20 review which can be accessed here: Pentax K20D Review: 18. Photographic tests (Noise): Digital Photography Review I picked up in the review where the discussion of noise begins: this is a direct comparison to Pentax competition. Also, below is an excerpt from the review which I find appropriate to this post:



"Although we would expect many K20D owners to be willing to indulge in some degree of post-processing, it's still important that the JPEG output be optimized (or, at least, optimizable for each user's tastes). Noise reduction is always a fine balance between reducing noise and retaining detail and there are different attitudes towards where that balance should be struck. The K20D gives the user a degree of choice about their preferred output - light nr, luminance nr only, luminance and chroma nr, stronger luminance and chroma nr. However, even this heaviest setting is only comparable to the default noise reduction settings of its peers (in terms of detail, as well as noise). The K20D doesn't give the option to produce the smeared but essentially noise-free images that others offer."


In summary, you have, in the handling of noise, Pentax' bold and unique approach which sets it apart from its competition, not in terms of quality of performance; rather, Pentax is set apart from its competition in terms of the autonomy it affords its user. This is, in a nutshell, why many people come to Pentax--THEY DO NOT COME TO PENTAX TO RESEMBLE THE COMPETITION---THEY GREW OUT OF DOING THAT IN HIGH SCHOOL--THEY COME TO PENTAX TO DISTINGUISH THEMSELVES FROM THE COMPETITION.
03-25-2009, 12:54 AM   #12
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QuoteOriginally posted by Jewelltrail Quote
It seems to me this issue of noise is one of the most misunderstood issues with Pentax cameras. I do not know how anyone would come to Pentax, without first having learned about Pentax' unique handling of noise.

The K20's difference in noise is more related to its "hands-off" philosophy than it is to the competition's better performance. The K20 shows more noise in its images ( as well as more detail) at default because the K20 provides the user with the freedom to strike the delicate balance between noise and detail for him/herself. It is that simple! The K20 is performing on a par with the competition in terms of noise, particularly when you consider the sensor size to MP ratio.

Pentax should be applauded for taking such a daring approach to the issue of noise because it demands a more educated and autonomous user. Educated and autonomous users are not the majority of buyers--one need consider this for a moment, me thinks. Even DPreview, not known as Pentax fanboys by the stretch of anyone's imagination, acknowledges this fact in its K20 review which can be accessed here: Pentax K20D Review: 18. Photographic tests (Noise): Digital Photography Review I picked up in the review where the discussion of noise begins: this is a direct comparison to Pentax competition. Also, below is an excerpt from the review which I find appropriate to this post:



"Although we would expect many K20D owners to be willing to indulge in some degree of post-processing, it's still important that the JPEG output be optimized (or, at least, optimizable for each user's tastes). Noise reduction is always a fine balance between reducing noise and retaining detail and there are different attitudes towards where that balance should be struck. The K20D gives the user a degree of choice about their preferred output - light nr, luminance nr only, luminance and chroma nr, stronger luminance and chroma nr. However, even this heaviest setting is only comparable to the default noise reduction settings of its peers (in terms of detail, as well as noise). The K20D doesn't give the option to produce the smeared but essentially noise-free images that others offer."


In summary, you have, in the handling of noise, Pentax' bold and unique approach which sets it apart from its competition, not in terms of quality of performance; rather, Pentax is set apart from its competition in terms of the autonomy it affords its user. This is, in a nutshell, why many people come to Pentax--THEY DO NOT COME TO PENTAX TO RESEMBLE THE COMPETITION---THEY GREW OUT OF DOING THAT IN HIGH SCHOOL--THEY COME TO PENTAX TO DISTINGUISH THEMSELVES FROM THE COMPETITION.
Excellent post.

I love this:
THEY DO NOT COME TO PENTAX TO RESEMBLE THE COMPETITION---THEY GREW OUT OF DOING THAT IN HIGH SCHOOL--THEY COME TO PENTAX TO DISTINGUISH THEMSELVES FROM THE COMPETITION
03-25-2009, 01:35 AM   #13
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I think nobody here actually read the original post : Henkezd's problem is not with chroma or luminance noises, but with broad blue/purple coloration of the pics occuring near the top and bottom borders... I have the same problem on my k20.
03-25-2009, 01:50 AM   #14
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QuoteOriginally posted by Jewelltrail Quote
It seems to me this issue of noise is one of the most misunderstood issues with Pentax cameras. I do not know how anyone would come to Pentax, without first having learned about Pentax' unique handling of noise.

The K20's difference in noise is more related to its "hands-off" philosophy than it is to the competition's better performance. The K20 shows more noise in its images ( as well as more detail) at default because the K20 provides the user with the freedom to strike the delicate balance between noise and detail for him/herself. It is that simple! The K20 is performing on a par with the competition in terms of noise, particularly when you consider the sensor size to MP ratio.

Pentax should be applauded for taking such a daring approach to the issue of noise because it demands a more educated and autonomous user. Educated and autonomous users are not the majority of buyers--one need consider this for a moment, me thinks. Even DPreview, not known as Pentax fanboys by the stretch of anyone's imagination, acknowledges this fact in its K20 review which can be accessed here: Pentax K20D Review: 18. Photographic tests (Noise): Digital Photography Review I picked up in the review where the discussion of noise begins: this is a direct comparison to Pentax competition. Also, below is an excerpt from the review which I find appropriate to this post:



"Although we would expect many K20D owners to be willing to indulge in some degree of post-processing, it's still important that the JPEG output be optimized (or, at least, optimizable for each user's tastes). Noise reduction is always a fine balance between reducing noise and retaining detail and there are different attitudes towards where that balance should be struck. The K20D gives the user a degree of choice about their preferred output - light nr, luminance nr only, luminance and chroma nr, stronger luminance and chroma nr. However, even this heaviest setting is only comparable to the default noise reduction settings of its peers (in terms of detail, as well as noise). The K20D doesn't give the option to produce the smeared but essentially noise-free images that others offer."


In summary, you have, in the handling of noise, Pentax' bold and unique approach which sets it apart from its competition, not in terms of quality of performance; rather, Pentax is set apart from its competition in terms of the autonomy it affords its user. This is, in a nutshell, why many people come to Pentax--THEY DO NOT COME TO PENTAX TO RESEMBLE THE COMPETITION---THEY GREW OUT OF DOING THAT IN HIGH SCHOOL--THEY COME TO PENTAX TO DISTINGUISH THEMSELVES FROM THE COMPETITION.
Excellent!! I too am a big fan of not forcing NR on users by default and giving them the choice!

... except it has almost nothing to do with the OP's problem... which looks like some color shift at higher ISO
03-25-2009, 07:57 AM   #15
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QuoteOriginally posted by dlacouture Quote
I think nobody here actually read the original post : Henkezd's problem is not with chroma or luminance noises, but with broad blue/purple coloration of the pics occuring near the top and bottom borders... I have the same problem on my k20.
I did...look at my lighting question.
What lighting do you see yours in?
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