Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
08-06-2016, 01:22 PM   #16
Site Supporter




Join Date: May 2016
Posts: 529
The DPreview photo doesn't have camera temperature, nor does it have a lot of the other expected exif data.

08-06-2016, 01:28 PM   #17
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,097
QuoteOriginally posted by leekil Quote
The DPreview photo doesn't have camera temperature, nor does it have a lot of the other expected exif data.
That is because it is not an out-of-camera JPEG. The metadata indicate a conversion from RAW using Lightroom.


Steve
08-06-2016, 01:36 PM   #18
Pentaxian
D1N0's Avatar

Join Date: May 2012
Location: ---
Photos: Gallery
Posts: 4,166
QuoteOriginally posted by leekil Quote
The DPreview photo doesn't have camera temperature, nor does it have a lot of the other expected exif data.
And no white dot issue
08-12-2016, 02:20 AM - 1 Like   #19
Tas
Site Supporter




Join Date: Aug 2013
Location: Brisbane, QLD
Photos: Gallery | Albums
Posts: 1,178
White dots do exist unfortunately

I have seen the white dots referenced in this thread. Here's my experience with them.

The first image is a series of images stacked using one of the composite options so the shutter speed reads 15s however it was probably 10-20 exposures of 15s combined in camera.

This is the original unworked DNG exported as jpeg for this thread


The next two images are crops of the above image after post processing. You'll notice the underexposure on the land sections in the main image so in post I pushed a bit harder to get the detail. The following image is a crop of the bottom left section to show the dots and hot pixels at their worst. This was the first time I'd seen the dots.


This crop is from a second copy where I did not push so hard on the details and the dots/hot pixels are still present but less obtrusive. The land sections of the image were unfortunately a bit soft to deal with the dots so the image is for the interwebs only.


The white dots are very hard to see when the image is viewed on a white background, but they are most certainly present. When I discovered these I thought wow, I've got a lot of stuck/hot pixels so I used the pixel mapping function and got on with it. However I haven't been doing a lot of long exposures of late and hadn't given it another thought until I saw the white dot comments aired again. It got me wondering so I went to some long exposure images and went looking.

I think the pixel mapping did help a bit but not completely. The dots are still present, most obviousl in the darker sections of the image but present in the lighter sections too.

To ensure you could see the white dots I went to two different long exposure images, made heavy crops and cranked up the brightness, contrast and clarity sliders in LR6.

This is an astro tracer image and shows the white dots on the ground (blurred from the sensor motion). The crop is from the bottom right corner of the frame.


The second is of the top left corner of the frame showing the night sky and trailing stars. This image is a straight bulb exposure.


My K-1 needs to be checked for the mirror issue so I will ask about the dots when it goes in.

08-12-2016, 08:34 AM   #20
Pentaxian
photoptimist's Avatar

Join Date: Jul 2016
Photos: Albums
Posts: 1,223
Even after the fix, Nikon warns users that they might see a white-dot issue on exposure times greater than 30 seconds. DFS, either in-camera or in post processing, is really the only way to address this issue.

It would be interesting to compare the amount of white dot pixels under controlled temperature conditions (cold, room-temperature, and hot camera internal temperatures) and as function of the camera temperature at the time of the last pixel mapping. My guess is that doing pixel mapping while the camera is hot would help remove the brightest of white dots.
08-12-2016, 05:57 PM   #21
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 855
Damn it, I was so hyped to get K-1, especially for stars because of the astro tracer feature. Wouldn't using dark frames introduce gaps into star trails?
08-12-2016, 07:52 PM   #22
Loyal Site Supporter
TedH42's Avatar

Join Date: Dec 2011
Location: Colorado
Photos: Gallery
Posts: 475
QuoteOriginally posted by awscreo Quote
Damn it, I was so hyped to get K-1, especially for stars because of the astro tracer feature. Wouldn't using dark frames introduce gaps into star trails?
If done using Slow Shutter Speed Noise Reduction in-camera, yes.

To have continuous star trails, it must be done in post-processing, using dark frames taken before and/or after the star shoot, with ISO and SENSOR temperature matching the conditions of the star shoot.
08-12-2016, 07:59 PM   #23
Pentaxian




Join Date: May 2016
Photos: Albums
Posts: 855
QuoteOriginally posted by TedH42 Quote
If done using Slow Shutter Speed Noise Reduction in-camera, yes.

To have continuous star trails, it must be done in post-processing, using dark frames taken before and/or after the star shoot, with ISO and SENSOR temperature matching the conditions of the star shoot.
Ok, that makes sense. Maybe this isn't that bad, just a quirk of the sensor..

08-24-2016, 01:07 AM   #24
Veteran Member




Join Date: Mar 2013
Posts: 318
QuoteOriginally posted by awscreo Quote
Damn it, I was so hyped to get K-1, especially for stars because of the astro tracer feature. Wouldn't using dark frames introduce gaps into star trails?
FYI, my K-1 doesn't have white dot issue problem in any conditions during astro photography.
DSP Firmware Version : 1.20.21.09
Production Code : 2.2
Manufacture Date : 2016:06:24
I am using it for almost one month 800+ shots, around 10% of them is astrophotography with or without astrotracer and not a single hint of a so called white dot issue.
More info in my comments here: Does the Pentax K-1 also has the white dots issue during long exposures? | Pentax Rumors
08-24-2016, 02:15 AM   #25
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 1,916
Original Poster
I have a fairly new K-1 as well, and there is definitely a white dot problem and or an unusual large amount of hot pixels during long exposures. I have only done some tests to see if the problem was there, and it was. Don’t know yet how big the problem will be (for me) in reality though.

Rawtherapee however seems to do a very good job of removing hot pixels and white dots without removing faint stars. At least that is what my first tests indicate.

Another thing to consider is that is seems to depend on the de-bayer algorithm if the white dots displays as white dots or “normal” hot pixels.

By using different algorithms (in rawtherapee you have a bunch to choose from) you get either lots of normal red, blue or green hot pixels and some white dots, or lots of white dots and some “normal” hot pixels.

So the amount of white dots seems to also depend on the raw-converter used.

Last edited by Gimbal; 08-24-2016 at 02:25 AM.
08-24-2016, 03:57 AM   #26
Veteran Member




Join Date: Mar 2013
Posts: 318
QuoteOriginally posted by Gimbal Quote
I have a fairly new K-1 as well
What is a manufacture date of your K-1?

Last edited by banep; 08-24-2016 at 04:10 AM.
08-24-2016, 06:06 AM   #27
Veteran Member
MJKoski's Avatar

Join Date: Aug 2016
Posts: 765
I have browsed this forum for a while after getting K-1 body in June and had to make an account when I saw this thread. The problem is very real and irritating one as I got rid of A7R2 + few top lenses to get a tilt screen and better long exposure performance. I ended up gaining nothing in LE performance due to these stupid white dots. Only way I have got clean long exposures with K-1 has been with multiexposure averaging using +100 frames. Before A7R2 I used R1 which got easily up to 5 minutes without LENR @ +15C. R2 has confetti style noise after 30 seconds in those temps but gains up really fast when temps drop to subzero levels.

I have used Nikon D800E and D810 (with white dot fix) bodies before and they have excellent noise control with long exposures. So does Canon 5Ds(r).

Those Nikons, Canons and Sony A7R1 however do not have IBIS. R2 and K-1 have IBIS and share bad LE performance. My guess it that IBIS does not let the sensor cool down properly. Maybe there is also some issue like D810 had which can(?) be fixed but it should be fixed ASAP.
08-24-2016, 08:53 AM   #28
Pentaxian




Join Date: Apr 2007
Location: Sweden
Posts: 1,916
Original Poster
QuoteOriginally posted by banep Quote
What is a manufacture date of your K-1?
DSPfirmware version 1.20.21.09 (the same)
Production date 2016:06:02 (slightly older)
Production code 2.1 (interesting, a difference. What does that mean?)

Above according to exiftool.
08-24-2016, 09:37 AM   #29
Veteran Member




Join Date: Mar 2013
Posts: 318
QuoteOriginally posted by Gimbal Quote
Production code 2.1 (interesting, a difference. What does that mean?)

Above according to exiftool.
That reminds me on product code on HP notebooks. As example same notebook with HDD from different manufacturer have different Product code.
I'm not 100% sure is that the same with Ricoh but different product(ion) code usually means that something has been changed inside a product during manufacturing.
Could be something like replacing some component with newer version functionally equal from the same supplier or from a different supplier because it is better/cheaper/whatever...
08-24-2016, 10:09 AM   #30
Pentaxian
Tjompen1968's Avatar

Join Date: May 2012
Location: Norrköping, Sweden
Photos: Gallery | Albums
Posts: 1,311
DSP Firmware Version : 1.20.21.09
Production Code : 2.2
Manufacture Date : 2016:03:05

I have the white dots in the shadows...
Reply

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!
astro, camera, data, dfs, dot, dslr, exif, exposure, exposures, ff, full frame, full-frame, heat, issue, k-1, k-1 white dot, k-5, k1, nikon, noise, pentax, pentax k-1, type, viewer
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: White Pentax K-r + White Kit Lens + 2 Extra Batteries + 1 Extra Charger MightyMike Sold Items 2 04-14-2015 07:21 AM
Lost white dot bassek Pentax SLR Lens Discussion 15 09-06-2012 10:22 AM
White Dot on 50mm f1.4 Super-Tak roboticspro Troubleshooting and Beginner Help 6 04-07-2011 03:03 AM
white dot on live view screen Shingkyo Pentax K-r 7 03-14-2011 06:54 AM
old lenses- that little plastic white dot? dandaniel Pentax SLR Lens Discussion 6 02-25-2009 02:13 PM



All times are GMT -7. The time now is 02:53 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