K1 and Digital 645

GlennG · 09-20-2016, 10:49 AM

With the K1 available now, what is the differential benefit for stepping up to a digital 645? Has there been any comparison between the two (or three, depending on how one considers the two digital 645's)?

CDW · 09-20-2016, 11:02 AM

The 645Z has a bit more DR, slightly better noise performance, as well as higher resolution, when compared to the K1 in the traditional single frame mode. When the situation allows the use of a tripod and there is no movement in the shot, the K1 in the pixel shift mode is a close match to the 645Z. My opinion based on using both. Comparisons of studio scenes can be made at Imaging-Resource or DPReview.

The K1 shoots at a higher frame rate and is more responsive when shooting bursts, as you would expect. OTOH, the noise performance of the Z is so good that you can easily shoot at ISO 800/16000 with almost no loss of image quality, enabling it to be used handheld in many situations. The sensors in both cameras excel in the ability to be pushed in shadow areas 4-5 stops, enabling highlights to be preserved by under exposing. The sensor in the K1 exhibits a 'white dot' noise problem with long exposures, requiring the Long Shutter Noise Reduction mode in the K1 to be used to mask the issue.

biz-engineer · 09-20-2016, 12:29 PM

Originally posted by CDW

The sensor in the K1 exhibits a 'white dot' noise problem with long exposures

Yes, all the time. That's encouraging.

stevebrot · 09-20-2016, 02:02 PM

Originally posted by CDW

The sensor in the K1 exhibits a 'white dot' noise problem with long exposures, requiring the Long Shutter Noise Reduction mode in the K1 to be used to mask the issue.

Oh, so is that a verified fact now? There are well-documented reports of this problem for some K-1 bodies and also credible reports from users who cannot reproduce the behavior on theirs. At present, evidence seems to indicate a manufacturing lapse that Pentax is addressing with some sort of sensor calibration. That calibration was reportedly not performed properly at the factory for some units.

Steve

GlennG · 09-21-2016, 06:31 PM

Thanks for the responses. Quite informative, and just the kind of information I was looking for.

Paul2660 · 09-22-2016, 07:57 AM

White dots are just part of sensor design. I have worked with 2 K1 cameras. Early ship and one from 2 weeks ago. Identical issues.

Net. Shoot a long exposure at a higher ISO 400 and up you will get white dots in the areas of shadow. Not to be confused with normal nose which on the K1 shows up as a faint grain.

Unlike Nikon which had the same problem the dots only seem to show up in shadows for me where as with Nikon the entire frame had them.

Features like pixel shift and Astrotracer over time seem to make the problem a bit worse.

Pentax USA is totally aware of the issue and their answer is use LEN which does remove them but is very wasteful on battery life and heats up the camera. As for a fix based on the posted attempts that were done to some K1 camera overseas I will just take the dots.

Pentax USA uses Precision Camera for repairs and personally I don't think they are setup for such a repair but that is just my feeling. This requires more than just dropping in parts.

One fix is to use Capture One for the raw conversion as it takes all the dots out with no loss of details.

Paul C

09-20-2016, 10:49 AM	#1
GlennG Veteran Member Join Date: Aug 2010 Location: Houston, Texas Posts: 824	K1 and Digital 645 With the K1 available now, what is the differential benefit for stepping up to a digital 645? Has there been any comparison between the two (or three, depending on how one considers the two digital 645's)?

09-20-2016, 11:02 AM	#2
CDW Site Supporter Join Date: May 2011 Location: Big Island, Hawaii & Utah Posts: 457	The 645Z has a bit more DR, slightly better noise performance, as well as higher resolution, when compared to the K1 in the traditional single frame mode. When the situation allows the use of a tripod and there is no movement in the shot, the K1 in the pixel shift mode is a close match to the 645Z. My opinion based on using both. Comparisons of studio scenes can be made at Imaging-Resource or DPReview. The K1 shoots at a higher frame rate and is more responsive when shooting bursts, as you would expect. OTOH, the noise performance of the Z is so good that you can easily shoot at ISO 800/16000 with almost no loss of image quality, enabling it to be used handheld in many situations. The sensors in both cameras excel in the ability to be pushed in shadow areas 4-5 stops, enabling highlights to be preserved by under exposing. The sensor in the K1 exhibits a 'white dot' noise problem with long exposures, requiring the Long Shutter Noise Reduction mode in the K1 to be used to mask the issue. Last edited by CDW; 09-20-2016 at 11:10 AM.

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09-20-2016, 12:29 PM	#3
biz-engineer Pentaxian Join Date: Feb 2015 Photos: Gallery Posts: 12,231	Originally posted by CDW The sensor in the K1 exhibits a 'white dot' noise problem with long exposures Yes, all the time. That's encouraging.

09-20-2016, 02:02 PM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by CDW The sensor in the K1 exhibits a 'white dot' noise problem with long exposures, requiring the Long Shutter Noise Reduction mode in the K1 to be used to mask the issue. Oh, so is that a verified fact now? There are well-documented reports of this problem for some K-1 bodies and also credible reports from users who cannot reproduce the behavior on theirs. At present, evidence seems to indicate a manufacturing lapse that Pentax is addressing with some sort of sensor calibration. That calibration was reportedly not performed properly at the factory for some units. Steve

09-21-2016, 06:31 PM	#5
GlennG Veteran Member Join Date: Aug 2010 Location: Houston, Texas Posts: 824 Original Poster	Thanks for the responses. Quite informative, and just the kind of information I was looking for.

09-22-2016, 07:57 AM	#6
Paul2660 Forum Member Join Date: Jun 2016 Posts: 67	White dots are just part of sensor design. I have worked with 2 K1 cameras. Early ship and one from 2 weeks ago. Identical issues. Net. Shoot a long exposure at a higher ISO 400 and up you will get white dots in the areas of shadow. Not to be confused with normal nose which on the K1 shows up as a faint grain. Unlike Nikon which had the same problem the dots only seem to show up in shadows for me where as with Nikon the entire frame had them. Features like pixel shift and Astrotracer over time seem to make the problem a bit worse. Pentax USA is totally aware of the issue and their answer is use LEN which does remove them but is very wasteful on battery life and heats up the camera. As for a fix based on the posted attempts that were done to some K1 camera overseas I will just take the dots. Pentax USA uses Precision Camera for repairs and personally I don't think they are setup for such a repair but that is just my feeling. This requires more than just dropping in parts. One fix is to use Capture One for the raw conversion as it takes all the dots out with no loss of details. Paul C