[weathermon]

Set the scope up tonight and got M1 - 25x5 mins incl the 5 frames from the other night. Had a snooze from 830 till 1045 when I set the scope up then snoozed from 11 till 145 while it took shots. Pretty happy with this. Sleep time again now - storms to chase tomorrow!

Attached Images

 

[smigol]

I'm working through my digital images from a recent star party while gathering more data during this current dark moon cycle.

This is NGC 7380 or the Wizard Nebula as seen at Calstar 2014.

I've changed my subexposure length to just 10 minutes vs 20 minutes as a way of minimizing the effect of RA drift or flexure. This required bumping the ISO setting to 200. The picture is the result of 33 subframes for 330 minutes of integration.

Still using the ancient Pentax K10D. Now water cooled!




I will be uploading more as I get through them.

[smigol]

This is a large region of nebulosity in Cepheus, near the more famous NGC 7635 (Bubble Nebula). Both regions are great for wide field study and I'm planning for either a mosaic or different lens/telescope combinations.

Stack of 20 total subexposures of 600 seconds for 200 minutes of integration. Modified and cooled Pentax 10D with Stellarvue SV4 scope under the skies at Calstar 2014.

[smigol]

One of the last digital images taken at Calstar 2014. This data was gathered in just one night. 27 frames of 600 seconds for 4 hours 30 minutes of integration.

Modified and cooled Pentax K10D on Stellarvue SV4 scope.




Note the tiny blue streak at the top of the image. That's the remaining, uncorrected amp glow after calibration. I have some ideas of how to fix this and will be testing in the future.

[duncan1]

Smigol, those shots are excellent; the K10D is still a fantastic performer.

Have you tried an OAG to tame your flexure problems?

[smigol]

Smigol, those shots are excellent; the K10D is still a fantastic performer.

Have you tried an OAG to tame your flexure problems?

I have an OAG device. Need to satisfy two problems before trying it:
1. More sensitive guide camera like a Lodestar or new QHY5LII
2. Shave down a T ring to mitigate the additional thickness the OAG will require. Considering a custom device made from a cheap lens mount to reduce adapter length.

With the 10 minute subs, I'm not giving up much sensitivity. There's still a little wander that shows up as eggy stars at 1:1 viewing. There are problems of flatness or tilt that should be solved, too.

Everything is put away in the shed for the next few weeks. If I get the chance to play with it a little, I'll put a depth gauge on the mount and see if there is sensor tilt that can be fixed without using shims. I have some thoughts about putting the shims under the mount after I take it off. Problem with doing this is that it's not necessary with camera lenses. May try a different T ring adapter to see if the tilt is inherent to this part.

[geo444]

.
Great Skies from Australia & California, congratulations guys !

heart of M33 Triangulum Galaxy shot with a Pentax Q10 on an old SkyWatcher 200/1000
No help from the Sky yesterday, despite the Neodymium filter, all is pink !
Hazy sky and moderate turbulence, temperature ~18-20°C

tiny Q10, a true killer if not limited to 30 sec :
www.pentaxforums.com/forums/38-photographic-technique/256035-astrophotography-k5-q-adapter.html#post2959867


M33 Triangulum Galaxy : ~2,700,000 L-Y from Home - apparent size : 70' × 40'
M33 Triangulum = Pentax Q10 + SkyGlow Filter + SkyWatcher 200/1000 = 60 x 30 seconds @ ISO 1600 :
stacking : DeepSkyStacker 3.3 - finish : Elements 3.0





Shot at sea level in a big city = lots of light-pollution + turbulence !

enjoy !

---

Last edited by geo444; 11-16-2014 at 08:09 AM.

[duncan1]

I have an OAG device. Need to satisfy two problems before trying it:
1. More sensitive guide camera like a Lodestar or new QHY5LII
2. Shave down a T ring to mitigate the additional thickness the OAG will require. Considering a custom device made from a cheap lens mount to reduce adapter length.

With the 10 minute subs, I'm not giving up much sensitivity. There's still a little wander that shows up as eggy stars at 1:1 viewing. There are problems of flatness or tilt that should be solved, too.

Everything is put away in the shed for the next few weeks. If I get the chance to play with it a little, I'll put a depth gauge on the mount and see if there is sensor tilt that can be fixed without using shims. I have some thoughts about putting the shims under the mount after I take it off. Problem with doing this is that it's not necessary with camera lenses. May try a different T ring adapter to see if the tilt is inherent to this part.

One problem that I had with my K10-D was slop in the T-ring. The locking slots were too big for the pins on the camera's flange and the camera rotated around the t-ring. My formulated fix was to use a pentax thread t-ring and then use the pentax k-mount to thread adapter.

I would have thought that you'd have lots of BF available?

[smigol]

I would have thought that you'd have lots of BF available?

The backfocus issue is because the flattener I use for the scope is specified for 55mm from the T thread to the sensor. The K mount has a 45 mm distance, leaving 10 mm left. This amount is taken up by the T thread to K mount adapter, usually perfectly.

The problem is that when adding an OAG device, that eats up additional distance, usually another 10 to 15mm of distance. That's why I'm considering making my own part to recover this lost distance.

If I could solve the sensor tilt issue perfectly, then I might epoxy the parts together.

[bladerunner6]

I have seen a few different people reference the Takumar 135. I have seen the K mount 2.5, 2.8 and 3.5 all at some reasonable prices. The 3.5 screw mount also looks pretty reasonable.

I would be using it with the GPS on a K-50.

Any recommendations or comments.

Thanks.

[SunValley]

I have seen a few different people reference the Takumar 135. I have seen the K mount 2.5, 2.8 and 3.5 all at some reasonable prices. The 3.5 screw mount also looks pretty reasonable.

I would be using it with the GPS on a K-50.

Any recommendations or comments.

Thanks.

I'll be looking at the replies to this one as l'm also looking for replacement of my -A 135 2.8 which has too much CA for my taste.
By looking at the reviews in the database I'd stay away from the bayonet ones. SMC Takumar and Super Takumar 135 2.5 get good reviews. I think this would be one of the best lens to work with the astrotracer. Enough reach for beautiful shots of most great nebulas of the Milky Way yet short enough to get between 1 and 2 min exposure with the tracer. Good luck!

[Tsuken]

I'll be looking at the replies to this one as l'm also looking for replacement of my -A 135 2.8 which has too much CA for my taste.
By looking at the reviews in the database I'd stay away from the bayonet ones. SMC Takumar and Super Takumar 135 2.5 get good reviews. I think this would be one of the best lens to work with the astrotracer. Enough reach for beautiful shots of most great nebulas of the Milky Way yet short enough to get between 1 and 2 min exposure with the tracer. Good luck!

I've used my Super-Multi-Coated Takumar 135/3.5 a couple of times, and have been very pleased with the results:


M42 in Orion (with starbursts) by -Occasionally Focused- - at f/5.6


Southern Cross (Crux) and Jewel Box by -Occasionally Focused- - probably f/5.6, but possibly f/4

[esben]

Does anyone know if a K200D would be any good for astrophotography? I'm interested of taking pictures of the milky way and other deep space imagery. What lense(s) would I need?

I had the K200D and I would say that you need very long exposures to get low noise results.

If you can stabilize it to get the long exposure then it would be fine to take picturs of the milky way across the sky. In other words, for wide field astro photography.

A 10-20mm lens would be a good choice.

If you want to make images with detailed deep sky opbjects like nebulae and clusters you need to talk and think about so many other things before you consider the camera.

In any way the best way to make sense of this is to try it somehow. I made a barn door tilting mount:

Barndoor Mount

that allows you to get exposures longer than 20 seconds without streaking stars.

Hope it helps

[Obin Robinson]

Here's M27. I took this photo with a Celestron ED80mm and my Pentax K-m. The gear was mounted to my Orion Skyview Pro EQ. There is no autoguiding in this photo. The total integration time is 20 minutes (forty 30 sec exposures) and I triggered the camera with the infrared remote. There were no darks, no flats, and no bias frames. I stacked the image in Deep Sky Stacker and tweaked the levels.



obin

[Stone G.]

Hunting meteors from the midst of my light-polluted city is a perhaps a bit silly but this was the first clear night in months.....

....and I just couldn't get my K-3, DA*200 and O-GPS1 work together on this night. Precise calibration was fairly painless, but tracking was lousy. So, on with my vintage Cosina Cosinon-W 35mm instead and then some 1½ hours searches in western Ursa Major. And this is what I got - no more, no less:


f/2.8 - 30 sec. at ISO 400



f/2.8 - 30 sec. at ISO 800