K-1 bulb mode question

mdurson · 04-02-2017, 05:47 PM

I have been struggling with the K-1 bulb mode, maybe somebody can help. I start the long exposure, and whatever time I chose for the exposure, the camera will afterwards count down that number of seconds or minutes. For example, if I chose an exposure time of two minutes, I will start the exposure and then stop it with the remote after 60 seconds, and then the camera starts to count down 60 seconds. Why does it do that? Does that mean I now have an exposure time of twice the amount, i.e. 120 seconds?

This is annoying because while it counts down, I can't do anything with the camera. If I have an exposure time of five minutes, I actually have to wait 10 minutes!

With any other camera, I do the long exposure, and after I click the shutter the second time, the exposure is done. What the Pentax does is confusing. Can someone please help??

BROO · 04-02-2017, 06:02 PM

It worried me at first too...
Have a read of this -Dark frame subtraction Dark-frame subtraction - Wikipedia

stevebrot · 04-02-2017, 07:11 PM

Originally posted by mdurson

Can someone please help??

Originally posted by BROO

Dark frame subtraction

Turn this off using the setting below

Rec Menu 2/Noise Reduction/Slow Shutter Speed NR

This may also be set using the "control panel".

BTW...Welcome to the Pentax Forums!

mdurson · 04-14-2017, 10:21 AM

Originally posted by BROO

It worried me at first too...
Have a read of this -Dark frame subtraction Dark-frame subtraction - Wikipedia

thank you, that helped!

mdurson · 04-14-2017, 10:21 AM

Originally posted by stevebrot

Turn this off using the setting below

Rec Menu 2/Noise Reduction/Slow Shutter Speed NR

This may also be set using the "control panel".

BTW...Welcome to the Pentax Forums!

thank you, that did it!

Gyroscope · 04-15-2017, 04:16 PM

You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing.

mdurson · 04-15-2017, 08:37 PM

Originally posted by Gyroscope

You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing.

Hmmm, if it makes that much of a difference, I will turn it back on and check it out. Thanks for the input!

Wheatfield · 04-15-2017, 08:58 PM

Originally posted by mdurson

Hmmm, if it makes that much of a difference, I will turn it back on and check it out. Thanks for the input!

You can also get very good results doing noise reduction as part of processing the image.

**Craigbob** · 04-17-2017, 11:02 AM

Originally posted by Gyroscope

You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing.

You can also take some dark frames (Cover the lens with the lenscap and take a few shots at the same exposure and temp as your main shots) after the session and subtract them from the main image in some program that does dark fram subtraction (Deep sky stacker, Nebulosity, Pixinsight, Photoshop etc...). This way you maximize your time taking images.

MJKoski · 04-18-2017, 09:00 AM

This setting can be programmed to the quick setting -panel! So it can be accessed with info-button anytime. Very handy for long exposure users. There are however exceptions to the rule - do not use it with pixel shift, it will ruin any detail advantage it gives. And you can also use multiexposure in-camera program to take, say, 100 shots and let camera compute one output RAW file from that. This will also smooth out moving parts like water. Averaging 100 shots gives so smooth file that dark frame subtraction is rarely needed for non-astro work.

Heebie · 05-09-2017, 01:51 PM

Thanks to several users for their notes on this. I just joined specifically to check on this issue.
It does seem excissive. I like the idea of keeping a set of the dark images around to subtract on demand.

04-02-2017, 05:47 PM	#1
mdurson New Member Join Date: Apr 2017 Posts: 5	K-1 bulb mode question I have been struggling with the K-1 bulb mode, maybe somebody can help. I start the long exposure, and whatever time I chose for the exposure, the camera will afterwards count down that number of seconds or minutes. For example, if I chose an exposure time of two minutes, I will start the exposure and then stop it with the remote after 60 seconds, and then the camera starts to count down 60 seconds. Why does it do that? Does that mean I now have an exposure time of twice the amount, i.e. 120 seconds? This is annoying because while it counts down, I can't do anything with the camera. If I have an exposure time of five minutes, I actually have to wait 10 minutes! With any other camera, I do the long exposure, and after I click the shutter the second time, the exposure is done. What the Pentax does is confusing. Can someone please help??

04-02-2017, 06:02 PM	#2
BROO Veteran Member Join Date: Feb 2016 Photos: Gallery \| Albums Posts: 655	Dark frame subtraction It worried me at first too... Have a read of this -Dark frame subtraction Dark-frame subtraction - Wikipedia

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04-02-2017, 07:11 PM	#3
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by mdurson Can someone please help?? Originally posted by BROO Dark frame subtraction Turn this off using the setting below Rec Menu 2/Noise Reduction/Slow Shutter Speed NR This may also be set using the "control panel". BTW...Welcome to the Pentax Forums!

04-14-2017, 10:21 AM	#4
mdurson New Member Join Date: Apr 2017 Posts: 5 Original Poster	Originally posted by BROO It worried me at first too... Have a read of this -Dark frame subtraction Dark-frame subtraction - Wikipedia thank you, that helped!

04-14-2017, 10:21 AM	#5
mdurson New Member Join Date: Apr 2017 Posts: 5 Original Poster	Originally posted by stevebrot Turn this off using the setting below Rec Menu 2/Noise Reduction/Slow Shutter Speed NR This may also be set using the "control panel". BTW...Welcome to the Pentax Forums! thank you, that did it!

04-15-2017, 04:16 PM	#6
Gyroscope Senior Member Join Date: Oct 2015 Photos: Gallery Posts: 166	You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing.

04-15-2017, 08:37 PM	#7
mdurson New Member Join Date: Apr 2017 Posts: 5 Original Poster	Originally posted by Gyroscope You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing. Hmmm, if it makes that much of a difference, I will turn it back on and check it out. Thanks for the input!

04-15-2017, 08:58 PM	#8
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,986	Originally posted by mdurson Hmmm, if it makes that much of a difference, I will turn it back on and check it out. Thanks for the input! You can also get very good results doing noise reduction as part of processing the image.

04-17-2017, 11:02 AM	#9
Craigbob Loyal Site Supporter Join Date: Mar 2017 Location: San Antonio, TX Photos: Albums Posts: 521	Originally posted by Gyroscope You might want to consider leaving this setting turned on particularly with longer exposures. Its annoying having to wait twice as long but the IQ results are better. If you have a second camera shoot that as well while the other is exposing. You can also take some dark frames (Cover the lens with the lenscap and take a few shots at the same exposure and temp as your main shots) after the session and subtract them from the main image in some program that does dark fram subtraction (Deep sky stacker, Nebulosity, Pixinsight, Photoshop etc...). This way you maximize your time taking images.

04-18-2017, 09:00 AM	#10
MJKoski Veteran Member Join Date: Aug 2016 Posts: 1,784	This setting can be programmed to the quick setting -panel! So it can be accessed with info-button anytime. Very handy for long exposure users. There are however exceptions to the rule - do not use it with pixel shift, it will ruin any detail advantage it gives. And you can also use multiexposure in-camera program to take, say, 100 shots and let camera compute one output RAW file from that. This will also smooth out moving parts like water. Averaging 100 shots gives so smooth file that dark frame subtraction is rarely needed for non-astro work.

05-09-2017, 01:51 PM	#11
Heebie Forum Member Join Date: May 2017 Location: Dublin, Ireland Photos: Albums Posts: 79	Thanks to several users for their notes on this. I just joined specifically to check on this issue. It does seem excissive. I like the idea of keeping a set of the dark images around to subtract on demand.