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04-17-2014, 03:05 PM   #781
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First results

Even the Moon is hard with the scope I have. Below is one of better shots I got without using the eyepiece. Using 10mm eyepiece I couldn't get anything but blurred white spot; it's moving so fast and the field of view is extremely narrow. I suppose if I waited until it was high in the sky and it wasn't full, I'd get somewhat better results.

I guess no way to keep it steady long enough to catch Saturn.

20140417-233641.jpg

04-22-2014, 02:28 PM - 1 Like   #782
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Caldwell 45 (NGC 5248)

A galaxy in the night sky as seen in the backyard. Done as a test for some fixes of flexure. 9 hours of integration with the Pentax K10D.




The annotated version shows a lot of galaxies hiding in the background:


Last edited by smigol; 08-31-2014 at 10:58 PM. Reason: fixed link
04-23-2014, 10:52 AM - 1 Like   #783
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I tried doing astrophotography years ago with a film camera that I had piggybacked on a little B&L telescope, and never got anything good out of it. Now that I have a K-3, I'd like very much to get into this area.

Last month, I took a trip out to Moab, Utah, and managed to get a few nice shots, but I'm still learning the post-processing involved. Here's one of them. I'm using the Astrotracer function of the GPS unit. I've found that with the 10mm lens, stars on the edges of the frame have trails, so this is a crop.


04-23-2014, 02:58 PM   #784
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QuoteOriginally posted by pesterle Quote
I tried doing astrophotography years ago with a film camera that I had piggybacked on a little B&L telescope, and never got anything good out of it. Now that I have a K-3, I'd like very much to get into this area.

Last month, I took a trip out to Moab, Utah, and managed to get a few nice shots, but I'm still learning the post-processing involved. Here's one of them. I'm using the Astrotracer function of the GPS unit. I've found that with the 10mm lens, stars on the edges of the frame have trails, so this is a crop.



Really nice. Since I've had my astrotracer I haven't seen, let alone photographed, the Milky Way.mplenty of stars, but just not seei the Milky Way. Weird.

This is really good. For processing, I think a good place to start is with Michael Shainblum's video tutorials on YouTube. I found them really helpful - even adapting them to what I can do on mg ipad. Now that I've got Lightzone on my computer I might re-watch them as well.

04-24-2014, 08:47 AM - 1 Like   #785
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Test of O-GPS1/Astrotracer on my new PENTAX K-3

QuoteOriginally posted by smigol Quote
A galaxy in the night sky as seen in the backyard. Done as a test ......
Well, I can never match the exquisite deep-sky detail that smigol and others can provide. But I do nevertheless find it rewarding to capture those tiny and faint patches of light, realizing that these photons have travelled for millions of years to be collected by my lens and captured on my sensor.

So, I have had certain hopes that the better spatial resolution of the K-3 sensor would benefit me in my hunt for these small galaxies, and here are my initial results.

All images have been taken with my smc Pentax-DA* 200mm f/2.8 lens.

First, just to test the general workings, a visit to Mars, currently residing in constellation Virgo:


Mars in Virgo. 6 exposures of 20s at ISO 3200 stacked in DSS. Clicki to see 20% view of original.

It was only as I developed my images that I found that I had actually caught - albeit only just and barely - my first deep-sky object, galaxy NGC 4941. But it is not "spectacular" by any measures so let's hasten on to Coma Berenices:



Region in Coma Berenices. 10 exposures at ISO 3200 stacked in DSS. Click to see 20% view of original.



The most prominent galaxies in this image are NGC 4565 to the south and NGC 4559 further to the north:


Spiral galaxy NGC 4559 in Coma Berenices. Click to see 100% view (crop of the above image)



Edge-on Spiral galaxy NGC 4565 in Coma Berenices. Click to see 100% view (crop of the above image)


I am happy to see that the overall shapes of these tiny galaxies are actually reasonably well rendered with my fairly modest 200mm lens and the K-3 sensor.


Finally a visit to Theta Leonis with is 'Leo triplet' of Galaxies:


Starfield with the Leo Triplet. Stack of 40 exposures of 20 seconds at ISO 3200 in DSS at apertures ranging from f/5.0 to f/.8.
Click to se 20% view of original.


The Leo triplet:Crop of the above image. Click to see 100% view.

Again, there is a reasonably well defined 'shape' to each of these galaxies. All in all, I think I shall be quite haqppy with my Pentax K-3 and O-GPS1 / Astrotracer combo.
04-24-2014, 03:46 PM   #786
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QuoteOriginally posted by Stone G. Quote
Well, I can never match the exquisite deep-sky detail that smigol and others can provide. But I do nevertheless find it rewarding to capture those tiny and faint patches of light, realizing that these photons have travelled for millions of years to be collected by my lens and captured on my sensor.

So, I have had certain hopes that the better spatial resolution of the K-3 sensor would benefit me in my hunt for these small galaxies, and here are my initial results.

All images have been taken with my smc Pentax-DA* 200mm f/2.8 lens.

First, just to test the general workings, a visit to Mars, currently residing in constellation Virgo:


Mars in Virgo. 6 exposures of 20s at ISO 3200 stacked in DSS. Clicki to see 20% view of original.

It was only as I developed my images that I found that I had actually caught - albeit only just and barely - my first deep-sky object, galaxy NGC 4941. But it is not "spectacular" by any measures so let's hasten on to Coma Berenices:



Region in Coma Berenices. 10 exposures at ISO 3200 stacked in DSS. Click to see 20% view of original.



The most prominent galaxies in this image are NGC 4565 to the south and NGC 4559 further to the north:


Spiral galaxy NGC 4559 in Coma Berenices. Click to see 100% view (crop of the above image)



Edge-on Spiral galaxy NGC 4565 in Coma Berenices. Click to see 100% view (crop of the above image)


I am happy to see that the overall shapes of these tiny galaxies are actually reasonably well rendered with my fairly modest 200mm lens and the K-3 sensor.


Finally a visit to Theta Leonis with is 'Leo triplet' of Galaxies:


Starfield with the Leo Triplet. Stack of 40 exposures of 20 seconds at ISO 3200 in DSS at apertures ranging from f/5.0 to f/.8.
Click to se 20% view of original.


The Leo triplet:Crop of the above image. Click to see 100% view.

Again, there is a reasonably well defined 'shape' to each of these galaxies. All in all, I think I shall be quite haqppy with my Pentax K-3 and O-GPS1 / Astrotracer combo.

Nice! It's great what can be done nowadays without the monstrous levels of equipment you'd generally think of.
04-24-2014, 08:34 PM   #787
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I'm wondering if it is feasible for the camera to use only a portion of the sensor while using the shake reduction as well as the extra sensor 'space' (that is not being used since only looking at portion of sensor) to track stars for longer periods of time (several minutes) ?

Would have smaller images but much more detail... if my non-technical technical dreaming actually worked.
04-24-2014, 08:41 PM   #788
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Found this site a few weeks back, hope it helps some:

Tripod Astrophotography - A Beginners Guide To Wide Field 35mm Photography.

04-25-2014, 04:18 AM - 1 Like   #789
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QuoteOriginally posted by mee Quote
I'm wondering if it is feasible for the camera to use only a portion of the sensor while using the shake reduction as well as the extra sensor 'space' (that is not being used since only looking at portion of sensor) to track stars for longer periods of time (several minutes) ?

Would have smaller images but much more detail... if my non-technical technical dreaming actually worked.
Nice idea, they would have to do live view on parts of the sensor.
Another idea is to first do an exposure without any kind of tracking, and then let the camera analyse the startrails to figure out the movement needed to counter act the trails. The next photo would then be with tracking using the calculated values.
04-25-2014, 06:06 AM   #790
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QuoteOriginally posted by Gimbal Quote
The next photo would then be with tracking using the calculated values
If I remember correctly, Canon (or was it Nikon?) took out a patent for that feature about the same time that the O-GPS1 / Astrotracer was released.
04-25-2014, 07:01 AM   #791
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QuoteOriginally posted by Stone G. Quote
If I remember correctly, Canon (or was it Nikon?) took out a patent for that feature about the same time that the O-GPS1 / Astrotracer was released.
I searched for a patent and found what seems to be almost the exact same idea, except they take a series of exposures (with some defined time between them) and then calculates the movement. That is then used in a long exposure with tracking activated.

It is filed 2011 by Hoya. Does that mean it could end up in a Pentax?

se patent US 20110285855 A1

Edit
current owner of the patent: PENTAX RICOH IMAGING COMPANY
04-25-2014, 08:33 AM   #792
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Interesting Gimbal, but I now found this thing about a Canon patent:

https://www.pentaxforums.com/forums/76-non-pentax-cameras-canon-nikon-etc/186...or-patent.html

(unfortunately, the link to New Camera now seems to have been broiken).
04-25-2014, 09:02 AM - 1 Like   #793
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QuoteOriginally posted by mee Quote
I'm wondering if it is feasible for the camera to use only a portion of the sensor while using the shake reduction as well as the extra sensor 'space' (that is not being used since only looking at portion of sensor) to track stars for longer periods of time (several minutes) ?

Would have smaller images but much more detail... if my non-technical technical dreaming actually worked.
There are a series of astrocameras that do this or similar. Part of the challenge is that CCDs and CMOS want to read all the data in the cells - you can't just check a few cells and let the others continue to accumulate.

Two types:
1. Some have a smaller sensor at the same plane as the main sensor that can be checked independently of the main sensor. Disadvantage is that it's a small sensor and sometimes there are no stars in that area. Advantage is that it does not sacrifice resolution.
2. Some have interleaved lines that can be polled independently. This would allow a full-size, lower resolution image to be checked periodically for tracking. Advantage is that it's a bigger size and thus more stars avaliable. Disadvantage is that it reduces the resolution of the image due to sacrificing the resolution.

Incidentally, some of the new camera sensors are already using some sensors to do live AF in movie mode. These sensors are a challenge for astrophotography because of the tricks that have to be done with processing. They leave data traces in bias signal that can blur or otherwise challenge calibration. Here is a link to a further discussion of this feature: http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5774679

Last edited by smigol; 04-25-2014 at 09:07 AM.
04-25-2014, 02:34 PM   #794
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That is interesting! Thanks for the posts, guys.
04-26-2014, 12:44 AM - 2 Likes   #795
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Popped outside last night with tripod, Takumar 135, and O-GPS1. First I nabbed the Southern Cross (and the Jewel Box, NGC4755)



Then I faced the other way and photographed Mars, but the turning around confused the astrotracer, vis:



Still, I looooooves me the astrotracer, with a big love.
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