[Stone G.]

Thanks again smigol.

ED glass or not, I guess these photographic lenses weren't optimized with astrophotography in mind. Well, we shall see, but to be prepared: Where do you source your filters?

[smigol]

The narrowband filter I mentioned was from Baader. It's a bit wide for astronomy use at 35 nm. A lot of astronomy is now done with much smaller bandpass. You can get 3, 6, 9 nm filters. I was able to use the astronomy-standard 48mm filter on the lens I mentioned because I put it inside the 67 to k mount adapter.

For general light pollution, I've been using the IDAS LPS-P2 filter. I have a 48mm version and a 77mm version. The 77 goes on lenses with the use of step-down rings as needed. It was because of this filter that I was able to see that near-IR was so strongly unfocused. My camera is modified for full-spectrum use and thus it's sensitive to wavelengths outside of the control of the IDAS filter. Thus, my color images all featured orange to red halos on nearly all stars. Very messy.

To solve this problem, I picked up some B+W 486 MRC filters. These have a hard cutoff at 700nm and so will act like a generous hot filter. I've not had the chance to test yet, even though the weather has been gorgeous for this recent new moon because I've been too busy.

To answer your question, I source my filters in the USA via Alpine Astro, OPT Corp, and Orion. I sometimes get stuff off astromart, too.

[VisualDarkness]

A one frame heavy crop of Saturn with Pentax Q + Kenko 1.5x PZAF + Pentax DA* 300mm F4. Sadly it was pretty cloudy but I'm surprised anyway with this "non-astro" setup.



And one of the moon with the same setup.



I want to go out tonight too but I can't decide on a subject. Maybe something nice with my 55/1.4 that I haven't tried for astro stuff?
Can you see something interesting on the skymap for me? Current night sky over Västerås - AstroViewer
I got no tracking though but a bunch of lenses, sadly in an urban area.

[Stone G.]

A one frame heavy crop of Saturn with Pentax Q + Kenko 1.5x PZAF + Pentax DA* 300mm F4. Sadly it was pretty cloudy but I'm surprised anyway with this "non-astro" setup..

Very impressive VisualDarkness! Maybe one should consider the (old) Q now that it has become so cheap?

I want to go out tonight too but I can't decide on a subject. Maybe something nice with my 55/1.4 that I haven't tried for astro stuff?
Can you see something interesting on the skymap for me? Current night sky over Västerås - AstroViewer
I got no tracking though but a bunch of lenses, sadly in an urban area.

If you haven't got it already, I suggest that you download an electronic star chart/planetarium program such as Cartes du Ciel:

start [Skychart]

For a number of reasons, I still use the old version 2.76.

Astro PC

Together with the associated catalogues that you can download from the same site, this gives me "all" I need for planning what to shoot and verifying what I did shoot.

[VisualDarkness]

Very impressive VisualDarkness! Maybe one should consider the (old) Q now that it has become so cheap?



If you haven't got it already, I suggest that you download an electronic star chart/planetarium program such as Cartes du Ciel:

start [Skychart]

For a number of reasons, I still use the old version 2.76.

Astro PC

Together with the associated catalogues that you can download from the same site, this gives me "all" I need for planning what to shoot and verifying what I did shoot.

Oh, there is a lot of data to download in the links, it has to be great! Thanks for the links.

I just pointed the Pentax K-5 and DA* 55/1.4 at the big dipper to try the performance. I'm surprised that the double star is so clear despite the turbulence and quickly falling temperature in the air. I judge the 55mm as good for the application so far.
30x6s stack ISO6400 F2.0

[smigol]

After nearly two months of not getting the gear out under the stars, I finally lugged everything to a local dark sky site.

Here's the area around M97 and M108 as seen with my scope and the modified and cooled K10D.

20 subframes at 1200 second duration, ISO 100 for 6.7 hours of integration.
Calibrated with Maxim with 20 darks, 40 flats, and 256 bias frames.
Stacked with DSS and processed with Pix Insight.

I'm mostly happy with the image, I tried to preserve the faint background galaxies at the tradeoff of letting the noise still be visible. I probably should learn a few more techniques with controlling noise.




The annotated version highlights the galaxies mentioned above.

[steve1307]

WOW seeing all those galaxies out there kinda reminds me just how small we are.

Fantastic image, big effort but definitely worth it.

[djseeram]

Nice picture smigol. How do you cool your K10D? And why ISO 100?

After nearly two months of not getting the gear out under the stars, I finally lugged everything to a local dark sky site.

Here's the area around M97 and M108 as seen with my scope and the modified and cooled K10D.

20 subframes at 1200 second duration, ISO 100 for 6.7 hours of integration.
Calibrated with Maxim with 20 darks, 40 flats, and 256 bias frames.
Stacked with DSS and processed with Pix Insight.

I'm mostly happy with the image, I tried to preserve the faint background galaxies at the tradeoff of letting the noise still be visible. I probably should learn a few more techniques with controlling noise.




The annotated version highlights the galaxies mentioned above.

[smigol]

Nice picture smigol. How do you cool your K10D? And why ISO 100?

Thanks! I've been through a few exercises with cooling my camera.

I originally had it modified by Spencers to remove the IR filter, making it sensitive to full-spectrum.
For about a year, I was cooling the outside of the camera with a peltier (TEC) device that was a power hog.
Earlier this year, I finally opened up the camera and added a cold finger to the frame inside the body. Because of the floating CCD for the shake reduction system, I could not put the cold finger directly on the sensor surface.
Instead, the cold finger touches the metal chassis and some of the components inside the frame. It does help to reduce noise and it stabilizes the temperature of the CCD as reported by EXIF.

Here are a few posts I made on my personal blog about the recent work on the camera.

The choice of ISO 100 goes back to some work I've done with measuring the readout noise of the system and maximizing dynamic range. Because the K10D is a CCD based system, the readout noise is not as adversely effected by ISO setting. For a year, I used 10 minute subs at 400 ISO. What I've found is that using 20 minute subs at ISO 100 gives cleaner results and a smoother noise texture than previous work at ISO 400. There are areas of amp glow that are unavoidable for the K10D. Because these areas have a non-linear noise profile, it can be difficult to remove them. Using ISO 100 also seems to help with controlling this amp glow as it will tend to saturate the data.

[pixelsaurus]

Thanks! I've been through a few exercises with cooling my camera.

I originally had it modified by Spencers to remove the IR filter, making it sensitive to full-spectrum.
For about a year, I was cooling the outside of the camera with a peltier (TEC) device that was a power hog.
Earlier this year, I finally opened up the camera and added a cold finger to the frame inside the body. Because of the floating CCD for the shake reduction system, I could not put the cold finger directly on the sensor surface.
Instead, the cold finger touches the metal chassis and some of the components inside the frame. It does help to reduce noise and it stabilizes the temperature of the CCD as reported by EXIF.

Here are a few posts I made on my personal blog about the recent work on the camera.

The choice of ISO 100 goes back to some work I've done with measuring the readout noise of the system and maximizing dynamic range. Because the K10D is a CCD based system, the readout noise is not as adversely effected by ISO setting. For a year, I used 10 minute subs at 400 ISO. What I've found is that using 20 minute subs at ISO 100 gives cleaner results and a smoother noise texture than previous work at ISO 400. There are areas of amp glow that are unavoidable for the K10D. Because these areas have a non-linear noise profile, it can be difficult to remove them. Using ISO 100 also seems to help with controlling this amp glow as it will tend to saturate the data.

Thanks for this post. I recently acquired a pre-loved K10D and when the weather shapes up, I am keen to try it out.

[tonypysm]

The colorful moon.K5 with takumar200/f4+APS 2X,20 exposures stacked.

[tonypysm]

Camera:Pentax K5
Mount:Astrotrc TT320
Lens:Ricoh 135/2.8@F4
Stack of 13 210Second exposures with ISO800,total 45min under the light pollution.
K5 did a good performance and it's not worse than my previous camera canon 1100DA for astrophotography.

[Ben_Edict]

Camera:Pentax K5
Mount:Astrotrc TT320
Lens:Ricoh 135/2.8@F4
Stack of 13 210Second exposures with ISO800,total 45min under the light pollution.
K5 did a good performance and it's not worse than my previous camera canon 1100DA for astrophotography.

This must be the most impressive single astro image I have seen with an unmodified Pentax camera. Fantastic work.

Ben

[oneeyedhawk]

Here is a shot with My k01 on the first clear night in a long time

M13 came out quite nicely hard to capture because it is so bright the center overexposes
to the left is spiral galaxy ngc 6207 at 12 mag
5- 30 sec exposure 6400 iso attached to a stellarvue 102 mm scope
stacked with deep sky stacker

I usually use my K5 The k01 is very comparable and lighter on the end of the scope
Hank

[jbinpg]

@tony - I echo the kudos. Fantastic result !!!

Jack