K-7 long exposure bug?


Anvh

Link Posted 05/02/2010 - 15:26
Here we go. link

Fixed pattern noise includes what are called "hot pixels," which are defined as such when a pixel's intensity far surpasses that of the ambient random noise fluctuations. Fixed pattern noise generally appears in very long exposures and is exacerbated by higher temperatures. Fixed pattern noise is unique in that it will show almost the same distribution of hot pixels if taken under the same conditions (temperature, length of exposure, ISO speed).
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 05/02/2010 - 15:26

greyhoundman

Link Posted 05/02/2010 - 17:29
The K200D is the last Pentax that you can turn off all DFS.
I use mine for astro work also. It is why I went with it, rather than a newer, higher MP camera.
http://swainphotography.smugmug.com/
http://www.flickr.com/photos/greyhoundman/

Anvh

Link Posted 05/02/2010 - 17:52
greyhoundman wrote:
The K200D is the last Pentax that you can turn off all DFS.
I use mine for astro work also. It is why I went with it, rather than a newer, higher MP camera.

The only stupid things it that it use CCD sensor and those are more prone to noise at longer exposure compared to the CMOS sensor which Pentax use now
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

PeteL

Link Posted 05/02/2010 - 17:59
I just tried my K7 on "B" and it too took about a minute before the ready lamp illuminated, Yet when i am using a normal timed exposure in other modes like "Manual" the Camera is ready to take the next shot almost instantaneously even with low speed NR switched on so if you are using 30 seconds or less perhaps you might find it better to use one of the normal shooting modes rather than B.
Regards - Pete
Last Edited by PeteL on 05/02/2010 - 17:59

iceblinker

Link Posted 05/02/2010 - 18:11
With Slow Shutter Speed NR turned off, B Mode on my K-7 only goes into a delay (DFS) after the exposure when it was a longer than 30 sec exposure.
~Pete

Anvh

Link Posted 05/02/2010 - 18:18
iceblinker wrote:
With Slow Shutter Speed NR turned off, B Mode on my K-7 only goes into a delay (DFS) after the exposure when it was a longer than 30 sec exposure.

The B mode is quite a specialized program mode and not used by many photographer besides for special types of photography.
I think it's safe to assume that people that use the B-Mode know what they are doing so why not give them an option to have it on or off?
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 05/02/2010 - 18:19

iceblinker

Link Posted 05/02/2010 - 18:23
Maybe Pentax really thought that no one would not want DFS. But they should know better! I'm not too bothered myself, but clearly a lot of photographers are bothered.
~Pete

Anvh

Link Posted 05/02/2010 - 18:28
Same here because I hardly do long exposure photography still how hard is it to have an off function besides on/auto?
I've never understand Pentax doing these things with the DFS, they indeed should have know better.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

Smeggypants

Link Posted 06/02/2010 - 06:39
This has been covered a few times. I was horrified the first time I took a 20 minute exposure wiht my K20D and wondered by the camera had locked up for a further 20 minutes.
[i]Bodies: 1x K-5IIs, 2x K-5, Sony TX-5, Nokia 808
Lenses: Pentax DA 10-17mm ED(IF) Fish Eye, Pentax DA 14mm f/2.8, Sigma 17-70mm f/2.8, Pentax-A 28mm f/2.8, Sigma 30mm F1.4 EX DC, Pentax-A 50mm f/1.2, Pentax-A 50mm f/1.4, Pentax-FA 50mm f/1.4, Pentax-A 50mm f/1.7, Pentax DA* 50-135mm f/2.8, Sigma 135-400mm APO DG, and more ..
Flash: AF-540FGZ, Vivitar 283

iceblinker

Link Posted 06/02/2010 - 10:41
Smeggy, the K20D doesn't have an "Off" setting for Slow Shutter Speed NR, whereas the K-7 does.

What confused me is that "Off" doesn't mean off! It means only off for less than 30 second exposures.

Perhaps this is mentioned in the manual. I forgot it if it is.
~Pete

greyhoundman

Link Posted 08/02/2010 - 19:46
I don't see all this noise in CCD's that everyone hoots about. My DS and K200D are very smooth on long, low light shots. And I don't use the DFS or noise reduction in camera. If I need a better signal to noise ratio, I stack photos.
http://swainphotography.smugmug.com/
http://www.flickr.com/photos/greyhoundman/

nass

Link Posted 24/02/2010 - 17:30
Please sign my petition to be able to disable DFS

http://www.petitiononline.com/p3ntax/petition.html

Thanks
... just another middle-aged guy with a hobby. I have an extreme macro learning site at extreme-macro.co.uk - Pentax-centric, your feedback and comments would be appreciated!
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