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K1 and white dot issues (Same as the D810)

Paul2660

Well-known member
JUST A NOTE TO ANYONE ELSE CONSIDERING THIS CAMERA FOR STAR TRAIL WORK, don't use it. The K1 suffers from the same darn issue the D810 had when it was announced, net millions of white dots throughout the image. Yes, if you turn on in camera long exposure noise reduction, you can eliminate most of them, but for star trails, (not Milky Way) this is total bust as you can't use long exposure noise reduction for stacking as you will gap excessively. I realize most folks don't do star trail work anymore, but I love it still and had hoped that Pentax would have done a bit of homework on this issue from Nikon's experience, as the cameras are using the same damn chip. Oh well.

The only way I know to get around it is with C1 as single pixel noise reduction most times will get a lot of them out, but that limits you to only one tool for work, and there are many times I get a better solution with LR and LR can't begin to handle this issue as shown below.

Paul C

no2 White Dots issue K1.jpg
 
below you will find some 1:1 crops in LR.

gallery of them for download is here

Problem is not so simple as I thought at beginning.

Most obvious @ ISO800 @114s very clearly visible in my shadow:




@some settings there are far less of them.
And @ some there almost not white pixels:
here ISO 3200 @30s


@ 15min shot I cannot see them @ ISO100



So finaly I set camera to interval shot 50x30s combinethem is PS @ simple white first and got:



So at this moment I thing that this issue can be solved by firmware update as there is no consistency in it.
Wait for Ricoh reply.

Final word: I have very weird weather condition. From one point of view Clouds @ sky went quite fast. From second, There was literally no wind in garden. So I have 15min shot with almost not moved leaves.
 

Paul2660

Well-known member
Thanks for posting,

It would be interesting to open the shot with your shadow (like that BTW) and see if the dots are still there. C1 seesms to have a lot more control on this.

Just a side note, your 2 examples of star trails, show why I stack. The single long continuous shot has just faint trails and the blue becomes possibly a bit over powering ( I love it others feel its not natural which is unfortunate). However your stack example shows just how many more stars you can pull in. Note, the faint gaps due to the shutter closing. These can be totally eliminated with "Star Tracer" software. Wonderful code windows only however. I don't know of any other software that will close the gaps.

Stacking takes a lot more time and you must be careful not to move the camera. However the end results IMO are well worth it.

Surprised you don't see the dots hardly at all on the single long 9xx second shot.

When you stack, I would run a max and mean stack, then combine them in CC, with the Max on Mean. then fade. Max will always pull much more noise and fading over mean, will give you a cleaner sky. Then run star tracer and hope you get a good solution!!

It's the Star Tracer step that the white dots will really hurt, as they are static in the stack, when star tracer moves the image to close the gaps, the dots become dotted lines.

Here is a simple article I wrote years ago, but it still mostly applies to stacking.

http://photosofarkansas.com/2014/09/23/092314-using-stacking-for-better-night-photography-results/

Paul C
 

Paul2660

Well-known member
The problem is identical to the D810 and early D800e Nikons. For some reason Capture One (thankfully) seems to have enough intelligence to remove the vast majority of the dots in the raw conversion, however if you shot was jpg you would be screwed totally.

I plan to open a case with Pentax US tomorrow, don't expect much, but will ask this to be sent up to Japan. I am sure the answer is already "use in camera noise reduction for long exposures" and that does work, but if you are stacking, can't do it as the gaps created can be excessive and next to impossible to fix. It's interesting that Pentax did not catch this or felt that the best solution was the in camera solution as Nikon figured out very quickly it was not and credit to Nikon they fixed it.

Here are two more screen shots, the one with white dots is a LR screen capture, the other is from C1. Difference is impressive.

Paul C
 

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