Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-22-2012, 03:24 PM   #1
Forum Member




Join Date: May 2011
Location: Helsinki
Photos: Gallery
Posts: 64
Pentax 645d bulb exposure

When I do long exposures in bulb I always need to wait the same amount as the exposure was. Lets say that my exposure time is 8 minutes and then I must wait another 8 minutes for the picture to be processed. Have been trying out everything in the menu so am I missing something or is this just the way the camera works? Because of the waiting time in long exposures I usually pick up my DSLR so I get done a few more shots/hour!

Thank you for all replies!

Cheers,
Jan

11-22-2012, 03:36 PM   #2
Inactive Account




Join Date: Dec 2008
Location: North Carolina
Photos: Albums
Posts: 1,720
That is the long exposure noise reduction. It takes another shot for the same length of time, but with the shutter closed, this is called a dark frame. Then it maps out the hot pixels that cause noise and removes them from the actual image.

Last edited by elliott; 11-22-2012 at 04:59 PM.
11-22-2012, 11:32 PM   #3
Forum Member




Join Date: May 2011
Location: Helsinki
Photos: Gallery
Posts: 64
Original Poster
How can I turn this off, it is driving me nuts?

Now I found a thread about this...
https://www.pentaxforums.com/forums/pentax-medium-format-645-6x7-645d/184221...posures-2.html

Last edited by jani80; 11-23-2012 at 11:42 AM.
11-26-2012, 05:24 AM   #4
Senior Member




Join Date: Nov 2008
Photos: Gallery
Posts: 241
Pentax should know that a dark frame is a necessity, but not for every individual shot. One frame can be obtained (at similar temperatures and exposure lengths) and used for several subsequent images in post processing. Pentax should make available to the user, the ability to turn noise reduction off for bulb exposures. One more reason (besides cost) to stick with film and the 67 if you do much long exposures.

11-29-2012, 10:56 AM   #5
Forum Member




Join Date: May 2011
Location: Helsinki
Photos: Gallery
Posts: 64
Original Poster
Thank you for the info. I am relatively new to long exposures

Jan
12-04-2012, 04:55 PM   #6
Pentaxian




Join Date: May 2011
Location: All over the place
Posts: 2,557
The option is there to turn the long exposure noise reduction off, but it doesn't switch it off. I have discussed this with both the Managing Director of Pentax UK and the European Servicing centre with no satisfactory results. Latest update hasn't changed this either. When only on battery power it would be nice to be able to do the dark frame at home after (two things make using AC power awkward - you need a battery pack which can be heavy - secondly in the UK the DC power supply costs, wait for it 160 - that's $260. Same part is priced in US at $99).
12-07-2012, 11:20 AM   #7
Senior Member




Join Date: Nov 2008
Photos: Gallery
Posts: 241
I was glad to see that on the Pentax K-01 noise reduction can be disabled for any exposure / ISO combination, including Bulb mode. For a professional camera like the 645D to not have this flexibility is inexcusable. Let the photographer decide how to expose their images.
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!
bulb, camera, exposure, exposures, medium format, minutes, time
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
645D hot pixel mapping in Bulb mode? alunfoto Pentax Medium Format 18 11-16-2012 10:28 AM
Perfect exposure time in Bulb mode gabro822 Pentax K-5 14 08-06-2012 05:09 AM
Long Bulb exposure on a K2000 BerndM Troubleshooting and Beginner Help 9 07-11-2012 07:31 PM
K20D bulb mode, the safest, longest exposure? minahasa Pentax DSLR Discussion 2 06-21-2012 08:52 AM
bulb mode vs timed exposure PaulfromTexas Photographic Technique 8 02-28-2011 12:26 PM



All times are GMT -7. The time now is 04:25 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