Upgrading from K-7 to K-5? (Bulb exposure)

Wisco · 05-21-2011, 05:42 PM

So I just noticed the new K-5 DSLR.
I have a K-7 and love it. The one thing I have been disappointed in is not being able to do long Bulb exposures of the night sky and stars.
If Pentax has fixed the issue with the K-5 I'd be willing to upgrade but this is a big selling point to me.
Anyone know if this has been fixed?
Also anything else to think of when upgrading my Pentax body?

I have a K-7
-DA 18-250mm
-DA 10-17mm
-Aftermarket remote switch (for long bulb exposures)

Thanks in advance for any advice or information,
Zach

Verglace · 05-21-2011, 06:55 PM

You can, set the mode dial to 'B'. Used it with a wireless remote, clicked once it started shooting, clicked again and it stopped

stormcloud · 05-21-2011, 07:09 PM - **1 Like**

if your talking DFS then yup k5 sorted that - also lower noise in general so all good for long exposures

Wisco · 05-21-2011, 07:30 PM

Yeah, it was that DFS issue. I'm glad they got that fixed.
Thanks.

I'll have to start sweet talkin' the wife tonight.

Kaufeetime · 05-22-2011, 07:15 AM

Originally posted by Wisco

Yeah, it was that DFS issue. I'm glad they got that fixed.
Thanks.

I'll have to start sweet talkin' the wife tonight.

Just buy it ~ have it sent to a friends address. Then at some point exchange the old with the new. If you use that secret credit card, you know the card that the better half doesn't know about; she would never know the difference. Don't tell her I gave you this idea.

philbaum · 05-22-2011, 07:49 AM

OK, i'll ask the stupid question. If you took a DF image for use later - what kind of software would allow one to remove that noise from the long exposures?

amoringello · 05-22-2011, 08:01 AM

Originally posted by philbaum

OK, i'll ask the stupid question. If you took a DF image for use later - what kind of software would allow one to remove that noise from the long exposures?

GIMP, Photoshop, or similar. Also probably plenty of one-trick ponies out there to do similar things. You simply need to do a Difference layer between the photo and the DF.

Just be sure you take this using the same settings on your camera and at about the same ambient temperature.
i.e. Shooting out on a cold night, then creating the DF at home the next day won't give as good of results.

philbaum · 05-22-2011, 12:42 PM

Originally posted by amoringello

GIMP, Photoshop, or similar. Also probably plenty of one-trick ponies out there to do similar things. You simply need to do a Difference layer between the photo and the DF.

Just be sure you take this using the same settings on your camera and at about the same ambient temperature.
i.e. Shooting out on a cold night, then creating the DF at home the next day won't give as good of results.

Thank you. Just take the picture against the lens cap then?

amoringello · 05-22-2011, 03:58 PM

Yep. Dunno how light-tight lens caps are, but that should pretty much do it.

HawaiianOnline · 05-22-2011, 05:41 PM

Any difference in taking a DF before or after a session of long exposures?

Skymist · 05-22-2011, 09:07 PM

We're getting great results with the K-5 for astrophotography - see the message thread.

**Ash** · 05-23-2011, 03:34 PM

Hi Zach,
It's not just DFS that made the K-7 unsuitable for Bulb exposures.
It was its sensor. It was Pentax's first generation CMOS sensor that was praised for less heat generation compared to its CCD predecessors. Even still, the CCD sensors produced beautifully clean Bulb exposures whereas the CMOS sensors in the K20D/K-7 struggled to create clean Bulb exposures even at ISO 100-200.

The K-5's sensor is revolutionary in this way. It's Pentax's first CMOS sensor that produces as clean long exposures as the older CCD sensors. This is a refreshing development for me, as I too appreciate the extra long exposures.

05-21-2011, 05:42 PM	#1
Wisco New Member Join Date: Sep 2009 Location: Lincoln, NE Posts: 7	Upgrading from K-7 to K-5? (Bulb exposure) So I just noticed the new K-5 DSLR. I have a K-7 and love it. The one thing I have been disappointed in is not being able to do long Bulb exposures of the night sky and stars. If Pentax has fixed the issue with the K-5 I'd be willing to upgrade but this is a big selling point to me. Anyone know if this has been fixed? Also anything else to think of when upgrading my Pentax body? I have a K-7 -DA 18-250mm -DA 10-17mm -Aftermarket remote switch (for long bulb exposures) Thanks in advance for any advice or information, Zach

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
bulb mode vs timed exposure	PaulfromTexas	Photographic Technique	8	02-28-2011 12:26 PM
Super Program / Super A -- bulb exposure	Zebooka	Film SLRs and Compact Film Cameras	7	04-10-2010 08:18 AM
Bulb mode on K200D and very long exposure	madbrain	Pentax DSLR Discussion	34	07-31-2008 01:06 PM
Time Exposure - Bulb setting - Read write times	Vatis	Pentax DSLR Discussion	7	09-05-2007 07:38 AM

05-21-2011, 06:55 PM	#2
Verglace Veteran Member Join Date: Mar 2011 Posts: 468	You can, set the mode dial to 'B'. Used it with a wireless remote, clicked once it started shooting, clicked again and it stopped

05-21-2011, 07:09 PM - 1 Like	#3
stormcloud Senior Member Join Date: Oct 2009 Posts: 232	if your talking DFS then yup k5 sorted that - also lower noise in general so all good for long exposures

05-21-2011, 07:30 PM	#4
Wisco New Member Join Date: Sep 2009 Location: Lincoln, NE Posts: 7 Original Poster	Yeah, it was that DFS issue. I'm glad they got that fixed. Thanks. I'll have to start sweet talkin' the wife tonight.

05-22-2011, 07:15 AM	#5
Kaufeetime Senior Member Join Date: Sep 2009 Location: Kansas City,Mo. Photos: Albums Posts: 206	Originally posted by Wisco Yeah, it was that DFS issue. I'm glad they got that fixed. Thanks. I'll have to start sweet talkin' the wife tonight. Just buy it ~ have it sent to a friends address. Then at some point exchange the old with the new. If you use that secret credit card, you know the card that the better half doesn't know about; she would never know the difference. Don't tell her I gave you this idea.

05-22-2011, 07:49 AM	#6
philbaum Veteran Member Join Date: Oct 2007 Location: Port Townsend, Washington State, USA Posts: 3,659	OK, i'll ask the stupid question. If you took a DF image for use later - what kind of software would allow one to remove that noise from the long exposures?

05-22-2011, 08:01 AM	#7
amoringello Veteran Member Join Date: May 2008 Location: Virginia, USA Photos: Gallery Posts: 1,562	Originally posted by philbaum OK, i'll ask the stupid question. If you took a DF image for use later - what kind of software would allow one to remove that noise from the long exposures? GIMP, Photoshop, or similar. Also probably plenty of one-trick ponies out there to do similar things. You simply need to do a Difference layer between the photo and the DF. Just be sure you take this using the same settings on your camera and at about the same ambient temperature. i.e. Shooting out on a cold night, then creating the DF at home the next day won't give as good of results.

05-22-2011, 12:42 PM	#8
philbaum Veteran Member Join Date: Oct 2007 Location: Port Townsend, Washington State, USA Posts: 3,659	Originally posted by amoringello GIMP, Photoshop, or similar. Also probably plenty of one-trick ponies out there to do similar things. You simply need to do a Difference layer between the photo and the DF. Just be sure you take this using the same settings on your camera and at about the same ambient temperature. i.e. Shooting out on a cold night, then creating the DF at home the next day won't give as good of results. Thank you. Just take the picture against the lens cap then?

05-22-2011, 03:58 PM	#9
amoringello Veteran Member Join Date: May 2008 Location: Virginia, USA Photos: Gallery Posts: 1,562	Yep. Dunno how light-tight lens caps are, but that should pretty much do it.

05-22-2011, 05:41 PM	#10
HawaiianOnline Veteran Member Join Date: Jan 2007 Location: Hawaii Posts: 613	Any difference in taking a DF before or after a session of long exposures?

05-22-2011, 09:07 PM	#11
Skymist Senior Member Join Date: Apr 2011 Location: Monterey Bay, Callifornia Posts: 107	We're getting great results with the K-5 for astrophotography - see the message thread.

05-23-2011, 03:34 PM	#12
Ash Loyal Site Supporter Join Date: Mar 2007 Location: Toowoomba, Queensland Photos: Gallery \| Albums Posts: 23,920	Hi Zach, It's not just DFS that made the K-7 unsuitable for Bulb exposures. It was its sensor. It was Pentax's first generation CMOS sensor that was praised for less heat generation compared to its CCD predecessors. Even still, the CCD sensors produced beautifully clean Bulb exposures whereas the CMOS sensors in the K20D/K-7 struggled to create clean Bulb exposures even at ISO 100-200. The K-5's sensor is revolutionary in this way. It's Pentax's first CMOS sensor that produces as clean long exposures as the older CCD sensors. This is a refreshing development for me, as I too appreciate the extra long exposures.