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09-02-2016, 12:56 AM   #121
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QuoteOriginally posted by Gimbal Quote
Nothing in the raw data? I guess that depends on which raw converter you use and what it does behind the scenes.
On the right side you have the raw data without hot pixel removal or chroma filters engaged, and to the left the with some filters activated. There are white dots there but in this case they are easily removed.
I was a little bit puzzled and don't know what exactly to answer to @ZeGaby.
Yes they exists in his raw file (ISO6400, 90s) but his problem is not even close to @MjKoski or this guy Pentax K1 White Dot Issue on Longer Exposures–Same as the other cameras using the Sony 36MP chip @ Photos Of Arkansas. Brightness of his white dots are similar to brightness of regular r/g/b noise and they are visible in every raw converter.
On the other hand on my black frame tests I have only red,blue and green dots of noise when viewing raw files using Pentax software provided with the camera (similar in Picassa using only Pentax RAW codec only). In my case in Lightroom it also shows white dots but just a few (I counted less than 10 of 36MP on every image, usualy 4-8).
Yes it looks like it is convertor dependent because they are more visible in Lightroom in compare to other raw convertors, at least on my computer.
I also think that on this level like in ZeGaby's raw file white dots could be relatively easily removed in post.

---------- Post added 09-02-16 at 10:04 AM ----------

QuoteOriginally posted by beholder3 Quote
If you want to see the actual raw content without software presharpening and other effects, use rawdigger or fastrawviewer.
Both can be used as testversions.
There is no white in there. Chroma noise is absolutely normal.
Thank you for your information, but what's wrong with simple Pentax RAW codec?
Just install codec and open the file at OS level with any viewer.
I used it for years with my K-5 and it works also with K-1 raw files.

09-02-2016, 05:22 AM   #122
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There is nothing wrong with using any software you want. Only if you want to check if a camera sensor produces things you do not want you have to look at raw data as raw as possible, because afterwards you only assess software design.

And the two tools I mentioned are by far the best tools to analyse raw data as they do neither presharpen nor denoise by default. A raw file must look soft, otherwise it's already been manipulated.

Looking at the same file with 4 different softwares I can say the noise impression in these files varies a lot. Even more so when having presharpening active plus different types of denoising. Those interestingly create the bright pixels.
09-02-2016, 05:29 AM   #123
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ZeGaby's file is different compared to output from my unit. I was just thinking after doing some statistical analysis of my exposures with K-1 - Excluding multiexposure photos the average exposure time has been ~25 seconds per photo. So...is there something which has failed inside my unit? Due to extremely long continuous exposures that is.
09-02-2016, 06:01 AM   #124
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QuoteOriginally posted by banep Quote
I was a little bit puzzled and don't know what exactly to answer to @ZeGaby.
Yes they exists in his raw file (ISO6400, 90s) but his problem is not even close to @MjKoski or this guy Pentax K1 White Dot Issue on Longer Exposures–Same as the other cameras using the Sony 36MP chip @ Photos Of Arkansas. Brightness of his white dots are similar to brightness of regular r/g/b noise and they are visible in every raw converter.
On the other hand on my black frame tests I have only red,blue and green dots of noise when viewing raw files using Pentax software provided with the camera (similar in Picassa using only Pentax RAW codec only). In my case in Lightroom it also shows white dots but just a few (I counted less than 10 of 36MP on every image, usualy 4-8).
Yes it looks like it is convertor dependent because they are more visible in Lightroom in compare to other raw convertors, at least on my computer.
I also think that on this level like in ZeGaby's raw file white dots could be relatively easily removed in post.

---------- Post added 09-02-16 at 10:04 AM ----------


Thank you for your information, but what's wrong with simple Pentax RAW codec?
Just install codec and open the file at OS level with any viewer.
I used it for years with my K-5 and it works also with K-1 raw files.
What RAW codec are you refering to? Do you have a link? I had the K-5 and it worked with a RAW codec from Pentax but the K-3 and K-1 does not work for me. (PEF and Windows)

09-02-2016, 09:12 AM   #125
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QuoteOriginally posted by MJKoski Quote
ZeGaby's file is different compared to output from my unit. I was just thinking after doing some statistical analysis of my exposures with K-1 - Excluding multiexposure photos the average exposure time has been ~25 seconds per photo. So...is there something which has failed inside my unit? Due to extremely long continuous exposures that is.
In order to learn something from comparing, you and Zegaby should first do the exactly same lens-cap-on shot: same exposure parameters, same temperatures. Interestingly your raw file at -14 degrees (beyond spec of the camera) has more bright noise spots than the one at 25 degrees.
Currently samples are too different.
09-02-2016, 09:49 AM   #126
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I can do same tests for a loaner unit which was promised to me next Monday and with the one which comes back from service some day. If someone wants to try out then feel free to do so.

My first test was +23C room temp and 2nd test @ -18C where the camera body was in freezer for 1 hour 30 minutes before taking the exposure. Shot parameters: ISO3200, 122 seconds. All noise reduction off in-camera.

-14C should be nothing for Pentax. I took A7R2 out in -35C in many occasions during the last winter. Usage in those temps was a PITA but it survived.
09-02-2016, 09:58 AM   #127
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QuoteOriginally posted by beholder3 Quote
In order to learn something from comparing, you and Zegaby should first do the exactly same lens-cap-on shot: same exposure parameters, same temperatures. Interestingly your raw file at -14 degrees (beyond spec of the camera) has more bright noise spots than the one at 25 degrees.
Currently samples are too different.
In the K1-K3 Long Exposure folder, i've made this !
K1 + M50mm @F/8.0 K3 + 35mm f/2.4 @F/8.0 side to side in a dark room
30s at different Iso (100 - 800 - 1600 - 3200 - 6400 - 12800 - 25600).
09-02-2016, 11:19 AM   #128
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QuoteOriginally posted by banep Quote
Thank you for your information, but what's wrong with simple Pentax RAW codec?
Just install codec and open the file at OS level with any viewer.
I used it for years with my K-5 and it works also with K-1 raw files.
It extracts the full-size JPEG preview...fully processed by the camera's JPEG engine.


Steve

09-02-2016, 12:33 PM   #129
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QuoteOriginally posted by Tjompen1968 Quote
What RAW codec are you refering to? Do you have a link? I had the K-5 and it worked with a RAW codec from Pentax but the K-3 and K-1 does not work for me. (PEF and Windows)
Yes that raw codec for K-5. I installed it on my computer to be able to open files directly in windows.
Don't know how it doesn't work for you.
When I got K-1 I didn't installed any software, just copied my K-1 raw files to my computer and I was able to open them with double click in windows.
Could be because of some other software previously installed before I got K-1 (I have experimented a lot before), but I was convinced that K-5 raw codec is responsible for successful opening of K-1 raw files.
09-02-2016, 02:57 PM   #130
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QuoteOriginally posted by ZeGaby Quote
In the K1-K3 Long Exposure folder, i've made this !
K1 + M50mm @F/8.0 K3 + 35mm f/2.4 @F/8.0 side to side in a dark room
30s at different Iso (100 - 800 - 1600 - 3200 - 6400 - 12800 - 25600).
I might add the body temperature for both K-1/K-3 starts at 25°C with the ISO 100 shots and ends at 26°C with the high ISO shots. For the K-3 we also have the actual sensor temperature which is already 27°C for the high ISO shot (the sensor heats up much faster than the whole metal body).
It's sad we don't have that sensor temp readout from the K-1 available.

MJKoski can now do a comparable shot to any of these and then you can compare the raw files.
09-03-2016, 06:52 PM   #131
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The more I read this thread and look at my own files, the less I am sure about what I am seeing. I have been using Adobe Camera Raw to view my DNG's (and other people's test shots) and some of the noise appears as white dots. I tried the FastRawViewer program and the noise appears as mostly red dots. Maybe it could be just a software issue in my case?

I have posted my dark-frame test shots here. They are all 30 second exposures. I have named the files by ISO, then camera temp as reported. The files ending in PM were taken after running pixel mapping. Obviously these are not very scientific tests since there are many combinations missing. Also I think I might not have blocked-out all of the light in some of the higher temp shots. The higher temp shots are ones I made just after first noticing the dots, and I was not being very methodical.

An interesting thing I have noticed is that when previewing my "white dot" shots on the K-1, the noise does appear as white dots when viewing at 100%. So I guess the K-1's internal preview takes a similar approach to noise as Adobe Camera Raw and others that show white dots? Has anyone else noticed the dots when previewing on the camera?
09-03-2016, 11:46 PM   #132
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QuoteOriginally posted by JBox Quote
The more I read this thread and look at my own files, the less I am sure about what I am seeing. I have been using Adobe Camera Raw to view my DNG's (and other people's test shots) and some of the noise appears as white dots. I tried the FastRawViewer program and the noise appears as mostly red dots. Maybe it could be just a software issue in my case?

I have posted my dark-frame test shots here. They are all 30 second exposures. I have named the files by ISO, then camera temp as reported. The files ending in PM were taken after running pixel mapping. Obviously these are not very scientific tests since there are many combinations missing. Also I think I might not have blocked-out all of the light in some of the higher temp shots. The higher temp shots are ones I made just after first noticing the dots, and I was not being very methodical.

An interesting thing I have noticed is that when previewing my "white dot" shots on the K-1, the noise does appear as white dots when viewing at 100%. So I guess the K-1's internal preview takes a similar approach to noise as Adobe Camera Raw and others that show white dots? Has anyone else noticed the dots when previewing on the camera?
It's a bright sunny morning here and my visibility is a little bit reduced but I can't see white dot problem in your last file named 6400T30.DNG.
09-04-2016, 04:08 AM   #133
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30 seconds is just on the edge where the problems start. Or, when you do any minor adjustments to the file in a converter like LR. Adding minor shadow boost or anything else like clarity explodes the file.

This is 10x30sec frame multiexposure @ ISO100 using in-camera average blending. Averaging 10 frames of ISO100 shots at 30 seconds should eradicate all noise on a modern camera body. Heck, the file should be clean with only one frame.



It has clarity upped by +40 in LR.



If I up the shadows the game ends in this case.
09-04-2016, 05:05 AM   #134
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QuoteOriginally posted by MJKoski Quote
30 seconds is just on the edge where the problems start. Or, when you do any minor adjustments to the file in a converter like LR. Adding minor shadow boost or anything else like clarity explodes the file.

This is 10x30sec frame multiexposure @ ISO100 using in-camera average blending. Averaging 10 frames of ISO100 shots at 30 seconds should eradicate all noise on a modern camera body. Heck, the file should be clean with only one frame.



It has clarity upped by +40 in LR.



If I up the shadows the game ends in this case.
Love the image you've captured here.

The in-camera and PP processes you describe are how I discovered the white dots with my K-1. Using the astro tracer is the only other time I've encountered them.

Tas
09-04-2016, 05:37 AM - 2 Likes   #135
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I think there may be a few factors in play here. In the previous example (nice image by the way!), while I might expect a few hot pixels to be visible (as these do not move between exposures), I would not expect to see a lot of other speckles visible, unless the file had been pushed excessively. One question on the image is to check the in-camera blending mode. Sure you wouldn't have got this wrong, but shadow noise result could occur using the blending mode set to 'bright' (and I have done this before ).

I also do wonder if the in camera 'average' blending mode really works perfectly as well - This is a guess based on the way the camera handles the averaging process, but I have the feeling it won't result in the same result as doing it in computer. I would like to compare in-camera averaging to doing it in computer at some point to check this out, I guess it's easy to check using a lenscap! Could this explain the disappointing cleanliness in the shadow areas of the file?

I prefer to average-stack RAWs in the computer for this and other reasons (less scope for user error like me selecting the wrong mode, and easier to remove 'bad' frames where there may be motion blur, tripod movement, unexpected incursions into the frame by companions, etc etc etc).

Moving to other comments, and considering single exposure 'white speckles', looking very critically at dark areas on the single-exposure 30 second, ISO 100 shot below, I can find I think 2 hot pixels (maybe I should do a mapping?). There is also chroma noise in the shadows (In actual fact, looking at the file, this is significantly more than I would expect I think).

One thing I do notice is that Lightroom's colour noise reduction does convert chroma noise into white speckles, and this happens at the default colour noise reduction setting from the Lightroom K-1 profile. However, these are *not* the same intensity as hot pixels, and turning down the colour LR slider reveals them as chroma noise and not hot pixels or white speckles or anything else. So when looking at 'white speckles' in Lightroom, do check that these are not really chroma noise that only looks white because of the colour noise reduction setting.




Not saying that the level of chroma noise is acceptable - but is this Lighroom factor a cause of some of the confusion here?

Of course, lifting shadows, or increasing highlights / clarity significantly will always result in showing up noise. Whether this matters to your scene is another matter. And of course, Lightroom while very good nowadays, cannot compete with a thorough photoshop approach that can apply different noise reduction strategies to different areas of an image (e.g. more aggressive NR in shadow areas, for example).

I for one would love to double check the performance of the K-1 against some other high-end bodies from other manufacturers - but the budget won't allow that!

John

Last edited by johnc; 09-05-2016 at 04:21 AM.
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