Forgot Password
Pentax Camera Forums Home
 

Closed Thread
Show Printable Version Search this Thread
05-09-2008, 08:46 AM   #1
Veteran Member




Join Date: Nov 2006
Location: Hong Kong
Posts: 1,934
Hot Pixels Issue of the K20D

Reports of the hot/dead pixels found in images produces by different K20D units continue and lately it has been reported by a DPR technical writer, who is responsible to review the K20D:-

DPR Pentax K20D Review [Page 1]: Pentax SLR Talk Forum: Digital Photography Review

"During testing we have encountered the same problems with hot pixels that have been reported elsewhere. We have continued to experience the same difficulties with a second production body and are currently awaiting a response from Pentax before proceeding with further testing."

So, where's the "elsewhere" as mentioned? Here it is:-

Test Pentax K20D - Wst瘼 - Optyczne.pl

Since the above review is in Polish, someone had summarised some of the key points and posted it below:-

K20D not recommended, inconsistent hot pixels issue

And, some of the key statements are quoted:-

"main issue was inconsistent quality between K20D samples, which they consider to be 'unusual development for Pentax products, and sad to see '. They tried a few different K20Ds, all had hot pixels, but was was particularly worrying was that hot pixels changed in each sessions, disappearing and appearing in different places. This appears to indicate production issues with the latest 14.6 megapixels sensor (made by Samsung)."

"See the above URL and go to section 7 for samples of noise and hot pixels. The site also found that there are many hot pixels (more than in other equipment they tested), and that the hot pixels are permanently mapped and excluded in JPEGs during in camera processing, thus there is more and more excluded hot pixels due to their unpredictable and changing appearance. It was unclear is there a way of resetting this mapping, but this would be fixable (if Pentax decides to do so) in future firmware."

For those who has limited bandwidth in accessing the Internet, a direct link of a sample picture showing many random hot pixels is here:-

http://www.optyczne.pl/upload2/7758_k20d_hoty.png

"The test had many other criticisms and discovered inconsistent quality issues. The very first K20D they purchased produced loud focusing noises, exposed badly, and was assembled badly -- it was replaced by a local distributor, and many issues were not present in the replacement... but some came back in the third K20D they tested."

Well, is there any report from real K20D end-users (not reviewers) for the hot pixel issue then? Yes, I've seen two new K20D reported about the hot pixels found in pictures produced by their K20D in a thread opened one month ago:-

有冇人試過CCD/CMOS有死點 (已維*蚹僕 8-5-2008) - Pentax 討論區 - DCHome.net 數碼天地論壇 *輕銌臚@*蚍すX相機網站 - Powered by Discuz!

(Post in Traditional Chinese, use BabelFish is required)

Direct link to a sample "hot" picture can be seen here.

The thread open person also reported that he had tried the K20D "pixel re-mapping" function, which is essentially a method to rule out known hot or dead pixel(s) by disabling particular pixel with problem and instructing the camera to use the neighbourhood pixel values to calculate (aka interpolate) a new value to insert into that dead pixel. However, he wrote that the problem could not be resolved even using this available function. So, finally, as the local Pentax service centre was unable to resolve the problem, they sent his unit back to Pentax Japan. The user has finally got back his K20D unit and he has made a quick post in telling us that the problem "has been resolved", with a small downsized sample picture posted too. But however, I am not sure if he has thoroughly tested his unit or not as he has not reported back further in details since then, despite he promised that there would be a more detailed "final" report ...

Afterall, it seems to me that it is just a hardware bug of the Samsung new CMOS sensor (for which Pentax was naive enough to hope that the firmware could eliminate the problem all). It might be that the pixel density are just too high as too many pixels are packed in a too small area with a too large photo site per pixel and with too little isolation/separtion between pixels too such that the whole sensor/image may become just too hot for the inside temperature when it is working. As such, the accumulated thermal energy, which possibly could not be drained away physically, has caused electrical signal noise got out of control somehow and finally those physically heated up pixels are recorded in the final image as hot pixel or even dead ones (if it constantly appeared red or green, usually).

Original article with all the quoted URLs contained:-
RiceHigh's Pentax Blog: Issue of Hot/Dead Pixels of the K20D


05-09-2008, 08:56 AM   #2
Veteran Member
rormeister's Avatar

Join Date: Dec 2007
Location: USA
Photos: Gallery
Posts: 626
All very interesting. Perhaps you need to consider changing your username to "PentaxBasher" so we can pick your posts out of the crowd a little easier.
05-09-2008, 08:58 AM   #3
Veteran Member




Join Date: Nov 2006
Location: Hong Kong
Posts: 1,934
Original Poster
QuoteOriginally posted by rormeister Quote
All very interesting. Perhaps you need to consider changing your username to "PentaxBasher" so we can pick your posts out of the crowd a little easier.
You mean you found "Pentax Bashing" "all very interesting"?? :-)
05-09-2008, 09:02 AM   #4
Inactive Account




Join Date: Nov 2007
Location: Sweden
Posts: 34
Sorry, now I'm confused. Is this forum some kind of cult?

05-09-2008, 09:10 AM   #5
Banned




Join Date: Oct 2007
Location: Savannah, U.S./Baguio City, P.H.
Posts: 5,979
sure is.
05-09-2008, 09:16 AM   #6
Veteran Member
rfortson's Avatar

Join Date: Sep 2006
Location: Houston TX
Photos: Gallery
Posts: 2,129
I guess I'd be surprised if a totally new sensor didn't have any problems. However, the DPReviewer and the Polish site were the only two places that mentioned this "issue". Since then a few more people have come forward.

However, if this really was a widespread issue like the VPN on the K10D, people would be howling. Has anyone noticed a reluctance of people to complain?? Me neither. If this was as widespread as it's insinuated, then every other post would be about this issue.

One disclaimer - DPReview said it was related to Live View, which I assume stresses the sensor more (produces heat). Heat is the enemy of electronics, so there may be something there. However, I've only tried Live View once or twice, and not for any long period.

FWIW, I've taken lots of shots at night with no hot pixels. I use Pentax Photolab, which does NOT remove hot pixels, so if they were there, I'd see them.
05-09-2008, 09:17 AM   #7
Veteran Member
rormeister's Avatar

Join Date: Dec 2007
Location: USA
Photos: Gallery
Posts: 626
QuoteOriginally posted by RiceHigh Quote
You mean you found "Pentax Bashing" "all very interesting"?? :-)
Nope. I've not been a member for very long here, but rarely do I ever hear anything constructive from you. Sorry, just my take on your extensive and exhausting attacks on the product. Perhaps you really should focus on a product you enjoy and be happy.
05-09-2008, 09:17 AM   #8
Forum Member




Join Date: Mar 2008
Location: So.Cal.
Photos: Gallery
Posts: 89
Whew!Guess I'm one of the lucky ones.No hot pixels here, at least that I have noticed yet.But the way I see it, even if a few do show up in the future, its much easier to spot those out in CS3 than siting at my light box with a 4x5 neg, brush, and bottle of spotone

05-09-2008, 09:25 AM   #9
Veteran Member




Join Date: Nov 2006
Location: Hong Kong
Posts: 1,934
Original Poster
Well..

QuoteOriginally posted by rormeister Quote
Nope. I've not been a member for very long here, but rarely do I ever hear anything constructive from you. Sorry, just my take on your extensive and exhausting attacks on the product. Perhaps you really should focus on a product you enjoy and be happy.
I don't agree with you here. I am not "attacking" products as you suppose. I am just reporting key product issues which have been confirmed to share, make some of the potential buyers to be aware before they are decided, and more importantly, hope that Pentax could eliminate those issues currently or at least in the future products.

Believe it or not, I am interested to buy every new Pentax DSLR bodies released. However, I haven't yet since the K10D just because of some of the confirmed issues (at least to me some are significant) or the new bodies have just little improvements than what I have been hoping or would expect over my current Pentax body.
05-09-2008, 09:40 AM   #10
Veteran Member
rormeister's Avatar

Join Date: Dec 2007
Location: USA
Photos: Gallery
Posts: 626
Then sir, I commend you on your well intended efforts to keep us thoroughly enlightened to the shortcomings of this camera. I must say, I'm glad I have the K10D which seems to have fallen off your radar. I can't find a single issue with the camera, speaking as a non-professional photographer of course.
05-09-2008, 09:41 AM   #11
Veteran Member
jeffkrol's Avatar

Join Date: Sep 2006
Location: Wisconsin USA
Photos: Gallery
Posts: 8,434
QuoteOriginally posted by RiceHigh Quote
I don't agree with you here. I am not "attacking" products as you suppose. I am just reporting key product issues which have been confirmed to share, make some of the potential buyers to be aware before they are decided, and more importantly, hope that Pentax could eliminate those issues currently or at least in the future products.

Believe it or not, I am interested to buy every new Pentax DSLR bodies released. However, I haven't yet since the K10D just because of some of the confirmed issues (at least to me some are significant) or the new bodies have just little improvements than what I have been hoping or would expect over my current Pentax body.
Instead of opening a new thread, you could have bothered to check if there was an ongoing one already....

https://www.pentaxforums.com/forums/pentax-news-rumors/26955-officially-emerg...-dpreview.html
Of course that wouldn't been sensational enough.... nor as easy for self promotion....
As to your helpfulness to Pentax and others... I best stop here before saying things others will regret
05-09-2008, 09:51 AM   #12
Forum Member




Join Date: Mar 2008
Location: So.Cal.
Photos: Gallery
Posts: 89
QuoteOriginally posted by RiceHigh Quote
I don't agree with you here. I am not "attacking" products as you suppose. I am just reporting key product issues which have been confirmed to share, make some of the potential buyers to be aware before they are decided, and more importantly, hope that Pentax could eliminate those issues currently or at least in the future products.

Believe it or not, I am interested to buy every new Pentax DSLR bodies released. However, I haven't yet since the K10D just because of some of the confirmed issues (at least to me some are significant) or the new bodies have just little improvements than what I have been hoping or would expect over my current Pentax body.
Rice, just curious, are you actually a photographer?I just checked your two web links and couldn't find any photographs with any artistic merit, or even vacation snap shots.They may be there, but if so, they are hard to navigate to.I've always had a hard time in my 35 years of doing this to take technical advice from those who are not credible photographers, whether it was film, developers, lenses, or in this era digital tools.
05-09-2008, 10:28 AM   #13
Senior Member
Peacekeeper's Avatar

Join Date: Jul 2007
Location: Back at work :(
Photos: Gallery
Posts: 169
"Reports of the hot/dead pixels found in images produces by different K20D units continue "

What 2 reports? out of how many thousands of camera users, have you seen the amount of Hot pixels in those pictures? Obviously that camera has a fault.

How many posts have we had of people syaing, "Hey my camera is locking up..blah blah blah" and the response is "Sounds like a dud camera get it replaced" and it is is and it is sorted.

Do those reports get REPORTED and turned into NEW Faults for ALL K20Ds......No!

If Hot Pixels were a problem as they are depicted on the Polish website then we would ALL be seeing them.

Go out try/buy, what ever and see for yourself instead of reporting other reports and beating it up into a story.


PK
05-09-2008, 10:42 AM   #14
Veteran Member
rormeister's Avatar

Join Date: Dec 2007
Location: USA
Photos: Gallery
Posts: 626
QuoteOriginally posted by cloudswimmer Quote
Rice, just curious, are you actually a photographer?I just checked your two web links and couldn't find any photographs with any artistic merit, or even vacation snap shots.They may be there, but if so, they are hard to navigate to.I've always had a hard time in my 35 years of doing this to take technical advice from those who are not credible photographers, whether it was film, developers, lenses, or in this era digital tools.
For my time here, we've seen a single image and this disclaimer
05-09-2008, 10:56 AM   #15
Forum Member
babelphotos's Avatar

Join Date: Oct 2007
Location: Canada
Photos: Gallery
Posts: 57
K20 and K10 here with *DA lenses.
No hot pixels, no focus noise on both of them.
So another one without it. Maybe they had bad Chineese copies...i dont know
Closed Thread

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!
camera, dslr, issue, issues, k20d, pentax, photography, picture, pixel, pixels, review, sample, unit
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hot Pixels GregK8 Troubleshooting and Beginner Help 8 03-04-2009 07:17 AM
hot pixels cobra333 Pentax DSLR Discussion 4 01-20-2009 07:21 AM
noticing my first hot pixels on k20d Isaac314 Pentax DSLR Discussion 10 12-16-2008 08:07 AM
Hot pixels richard64 Pentax DSLR Discussion 4 08-05-2008 05:50 PM
To all concerned with K20D/Hot Pixel Issue codiac2600 Pentax DSLR Discussion 170 06-24-2008 05:28 AM



All times are GMT -7. The time now is 12:15 AM. | 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