Astrophotography

**smigol** · 03-13-2012, 07:14 PM - **2 Likes**

OK, since we're looking at Orion, here's mine from Dec 24, 2011:

Image details: An extensive rework of this set of images from Dec 24, 2011 at Montebello OSP.
Taken with my full-spectrum modified Pentax K10D camera using the Stellarvue SV4.
Guided with PHD using the Orion SSAG on a SV70ED. Sitting on a Losmandy GM-8 that I've recently upgraded with the OPW and high precision gear.

Stacked with DSS using:
Stacking step 1 ->2 frames (ISO: 100) - total exposure: 1 mn 56 s
Stacking step 2 ->6 frames (ISO: 100) - total exposure: 11 mn 54 s
Stacking step 3 ->3 frames (ISO: 100) - total exposure: 15 mn 0 s
Stacking step 4 ->1 frames (ISO: 100) - total exposure: 10 mn 2 s

Processed with PixInsight. DBE, 50 iterations of Masked Stretch to .09 median value and then another 50 to .1 value. Slight histogram stretch to tweak. Exported to LR3 where I did final touchup.

This one made it into the Pentax Photo Gallery.

GWARmachine · 03-13-2012, 09:24 PM

Originally posted by Ex Finn.

Yes sir, nice shot. I tried stacking, not for me. So, anyone try astro-trac with a actual telescope?.

The maximum load capacity of the AstroTrac is 33lbs so there is plenty of room to work with. Some people use smaller refractors with the AstroTrac and it works fine. I don't have a dedicated CCD for astro-imaging and I only have a large reflector telescope. But... the K-5 and my lenses are pretty much the same thing and it works GREAT! I've used my AstroTrac with a 300mm lens on the K-5 and it maintained excellent tracking. I haven't tried any higher lenses yet, mainly because I don't own any. What I've got seems to work well I think. Theres a Pentax 300mm f/2.8 for sale here but its $1900!!! WOW! I want it in my arsenal!

**oneeyedhawk** · 03-14-2012, 10:56 AM

The maximum load capacity of the AstroTrac is 33lbs?

Where did you find the weight capacity of an Astro Trac? I thought the only movement was sensor shift and not scope shift or camera shift. Why is there a weight max.
I must be incorrect in my thinking on how the astro trac works.

I know the light path through a scope has to cover the camera sensor. A very long FL. scope might not cover the entire sensor and produce short tracking times.

Hank

Gimbal · 03-14-2012, 12:58 PM

Originally posted by oneeyedhawk

Where did you find the weight capacity of an Astro Trac? I thought the only movement was sensor shift and not scope shift or camera shift.

They are talking about something else, see Astrophotography Made Easy - Home

smigol, that is just too good.

GWARmachine · 03-14-2012, 02:47 PM - **1 Like**

I think you're thinking of the O-GPS1, right?... the "Astro-Tracer" function of the GPS unit for Pentax? What Gimbal showed above with the link is what I have (and LOVE). I just got tired of visual astronomy and decided not to buy a whole scope and mount and stuff.

**oneeyedhawk** · 03-14-2012, 05:24 PM

You are correct. Completely did not think about the astro trac mount. I thought this thread was a discussion was about the Astro tracer and its use with the K5 and the Kx pentax cameras. I have never used the astro trac although I have heard great things about it. Right now I'm trying to find the best way to use the Astro tracer. A little confusion
sorry
Hank

GWARmachine · 03-14-2012, 08:01 PM

Originally posted by oneeyedhawk

You are correct. Completely did not think about the astro trac mount. I thought this thread was a discussion was about the Astro tracer and its use with the K5 and the Kx pentax cameras. I have never used the astro trac although I have heard great things about it. Right now I'm trying to find the best way to use the Astro tracer. A little confusion
sorry
Hank

I was actually thinking of purchasing the O-GPS1 as well so please share any positive or negative experiences with it here too. And of course photos and info are always great to see.

mrjamesabels · 03-14-2012, 08:52 PM

It would be insane if Google Sky Map ran along side with 0-Gps1. Built-in android. I have some issues with calibration but doing a precise calibration again usually fixes it. I haven't full tested it enough. I live in a polluted area. I plan to drive to some dark areas again. 1st 2 were shot for 3 minutes at 10mm in upper stat NY and last one shot for 30 seconds at 300mm in a heavily polluted area in NJ. Im still a newbie at this so I need more practice.

**smigol** · 03-15-2012, 08:42 AM

One more before I take off this morning...

M8 and Trifid Nebula as seen on June 25, 2011. Taken with an Unmodified Pentax K10D camera using the smc P-A* 300mm f4.0 lens at f5.6. I used an IDAS LPR-2 filter on the lens as well to help reject the inevitable light pollution. Subs were 16 frames of 5 minutes at 400 ISO (1 hour, 20 minutes). Used Losmandy GM8 mount guided by PHD with Orion SSAG on a Stellarvue SV70ED.

This image has been a long time coming. I originally captured the lights back in June 2011 and grabbed some darks at the same time as well. However, because the way that the software doesn't like the darks, it was really difficult to remove the amp glow that appears along the edge. After doing all the registration and calibration with darks that are at the same temperature as the lights, I was finally able to bring the FIT file into PI where I worked it over pretty aggressively.

As the corners were pretty badly distorted by coma, I've cropped them out as well as the amp glow.

This was the last of my efforts with using pef files. I've since gone over to dng.

**Ex Finn.** · 03-16-2012, 02:47 PM

I was just curious about the Astro-Trac, never seen a picture of it set up with a "heavy" long focal length refractor.
I am pretty sure the O-GPS1 will not yield much of exposure time with 900 mm fl.
Awesome images from everyone, thank`s for sharing.

**oneeyedhawk** · 03-22-2012, 10:52 AM

Last nights (3/21/2012) M42-Orion nebula Mag 5 skies Pentax K5 through a Astro tec RC-6; 12- 15 seconds frames stacked with deep sky stacker
The Pentax really gets great detail and the stars do not blow out
Hank

Ben_Edict · 03-24-2012, 02:21 PM

Fantastic images here.*I think, I need the O-GPS1 as an easy going alternative to the fully fledged mount and scope stuff. I find all of your images quite encouraging, given, that Pentax seems to be even rarer among astrophotographers, than among the common photog horde. Since the 67 vanished, Pentax has lost out in the skies... Has the comparetively low red sensitivity of Pentax DSLRs improved with the K5? I don't know, haven't seen a diagram of spectral response so far.

Ben

hockmasm · 03-25-2012, 04:31 PM

@smigol Great shot of Orion! Man that is such a beautiful photo!

Stone G. · 04-03-2012, 04:22 PM

Sigh - - - I cannot really compete with these magnificent deep-sky delicacies. So, from my fourth floor balcony in the light polluted city, I retreat to something more tangible: The good old Moon.

And here then, we have the Sun rising over the magnificent crater Copernicus south of Mare Imbrium - The Sea of Rains. Note how the sun rays just touch the western rim of copernicus while the crater floor is still in pitch black darkness.

To the north, the also great crater Plato lies fully bathed in sunshine and to the south-east, the Appenine Mountains look truly rugged and "wild" (much more than they actually are) in the low sun with the resulting strong shaddows.

Click on image to see larger version:

The gear used for this image is fairly simple: A small 4" f/10 Vixen Polaris R-100L Newtonian and a Tamron SP F-series 2X teleconverter, giving an EFL of 2000mm and a focal ratio of f/20. 7 images of 1/20 sec at ISO 400 stacked in Registax and post-processed in PhotoImpact. Image taken with a Pentax K-5.

zambonikane · 04-05-2012, 11:01 AM

Here is a compilation of about almost 2 hours worth of 5min subs of M51. Details of the imaging train are in the link.

03-13-2012, 09:24 PM	#242
GWARmachine Senior Member Join Date: Sep 2011 Location: New Bern, NC Photos: Albums Posts: 138	33 Pounds of Gear Originally posted by Ex Finn. Yes sir, nice shot. I tried stacking, not for me. So, anyone try astro-trac with a actual telescope?. The maximum load capacity of the AstroTrac is 33lbs so there is plenty of room to work with. Some people use smaller refractors with the AstroTrac and it works fine. I don't have a dedicated CCD for astro-imaging and I only have a large reflector telescope. But... the K-5 and my lenses are pretty much the same thing and it works GREAT! I've used my AstroTrac with a 300mm lens on the K-5 and it maintained excellent tracking. I haven't tried any higher lenses yet, mainly because I don't own any. What I've got seems to work well I think. Theres a Pentax 300mm f/2.8 for sale here but its $1900!!! WOW! I want it in my arsenal!

03-22-2012, 10:52 AM	#251
oneeyedhawk Site Supporter Join Date: Dec 2011 Location: Loveland C0. Photos: Gallery \| Albums Posts: 93	Last nights (3/21/2012) M42-Orion nebula Mag 5 skies Pentax K5 through a Astro tec RC-6; 12- 15 seconds frames stacked with deep sky stacker The Pentax really gets great detail and the stars do not blow out Hank Attached Images

04-03-2012, 04:22 PM	#254
Stone G. Pentaxian Join Date: Jun 2010 Location: North Zealand, Denmark Photos: Gallery \| Albums Posts: 1,516	Back to Basics Sigh - - - I cannot really compete with these magnificent deep-sky delicacies. So, from my fourth floor balcony in the light polluted city, I retreat to something more tangible: The good old Moon. And here then, we have the Sun rising over the magnificent crater Copernicus south of Mare Imbrium - The Sea of Rains. Note how the sun rays just touch the western rim of copernicus while the crater floor is still in pitch black darkness. To the north, the also great crater Plato lies fully bathed in sunshine and to the south-east, the Appenine Mountains look truly rugged and "wild" (much more than they actually are) in the low sun with the resulting strong shaddows. Click on image to see larger version: The gear used for this image is fairly simple: A small 4" f/10 Vixen Polaris R-100L Newtonian and a Tamron SP F-series 2X teleconverter, giving an EFL of 2000mm and a focal ratio of f/20. 7 images of 1/20 sec at ISO 400 stacked in Registax and post-processed in PhotoImpact. Image taken with a Pentax K-5. Last edited by Stone G.; 04-03-2012 at 04:32 PM.

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03-13-2012, 07:14 PM - 2 Likes	#241
smigol Site Supporter Join Date: Sep 2008 Location: Menlo Park, CA Photos: Albums Posts: 422	OK, since we're looking at Orion, here's mine from Dec 24, 2011: Image details: An extensive rework of this set of images from Dec 24, 2011 at Montebello OSP. Taken with my full-spectrum modified Pentax K10D camera using the Stellarvue SV4. Guided with PHD using the Orion SSAG on a SV70ED. Sitting on a Losmandy GM-8 that I've recently upgraded with the OPW and high precision gear. Stacked with DSS using: Stacking step 1 ->2 frames (ISO: 100) - total exposure: 1 mn 56 s Stacking step 2 ->6 frames (ISO: 100) - total exposure: 11 mn 54 s Stacking step 3 ->3 frames (ISO: 100) - total exposure: 15 mn 0 s Stacking step 4 ->1 frames (ISO: 100) - total exposure: 10 mn 2 s Processed with PixInsight. DBE, 50 iterations of Masked Stretch to .09 median value and then another 50 to .1 value. Slight histogram stretch to tweak. Exported to LR3 where I did final touchup. This one made it into the Pentax Photo Gallery.

03-14-2012, 10:56 AM	#243
oneeyedhawk Site Supporter Join Date: Dec 2011 Location: Loveland C0. Photos: Gallery \| Albums Posts: 93	The maximum load capacity of the AstroTrac is 33lbs? Where did you find the weight capacity of an Astro Trac? I thought the only movement was sensor shift and not scope shift or camera shift. Why is there a weight max. I must be incorrect in my thinking on how the astro trac works. I know the light path through a scope has to cover the camera sensor. A very long FL. scope might not cover the entire sensor and produce short tracking times. Hank

03-14-2012, 12:58 PM	#244
Gimbal Pentaxian Join Date: Apr 2007 Location: Sweden Posts: 2,106	Originally posted by oneeyedhawk Where did you find the weight capacity of an Astro Trac? I thought the only movement was sensor shift and not scope shift or camera shift. They are talking about something else, see Astrophotography Made Easy - Home smigol, that is just too good.

03-14-2012, 02:47 PM - 1 Like	#245
GWARmachine Senior Member Join Date: Sep 2011 Location: New Bern, NC Photos: Albums Posts: 138	I think you're thinking of the O-GPS1, right?... the "Astro-Tracer" function of the GPS unit for Pentax? What Gimbal showed above with the link is what I have (and LOVE). I just got tired of visual astronomy and decided not to buy a whole scope and mount and stuff.

03-14-2012, 05:24 PM	#246
oneeyedhawk Site Supporter Join Date: Dec 2011 Location: Loveland C0. Photos: Gallery \| Albums Posts: 93	You are correct. Completely did not think about the astro trac mount. I thought this thread was a discussion was about the Astro tracer and its use with the K5 and the Kx pentax cameras. I have never used the astro trac although I have heard great things about it. Right now I'm trying to find the best way to use the Astro tracer. A little confusion sorry Hank

03-14-2012, 08:01 PM	#247
GWARmachine Senior Member Join Date: Sep 2011 Location: New Bern, NC Photos: Albums Posts: 138	Originally posted by oneeyedhawk You are correct. Completely did not think about the astro trac mount. I thought this thread was a discussion was about the Astro tracer and its use with the K5 and the Kx pentax cameras. I have never used the astro trac although I have heard great things about it. Right now I'm trying to find the best way to use the Astro tracer. A little confusion sorry Hank I was actually thinking of purchasing the O-GPS1 as well so please share any positive or negative experiences with it here too. And of course photos and info are always great to see.

03-15-2012, 08:42 AM	#249
smigol Site Supporter Join Date: Sep 2008 Location: Menlo Park, CA Photos: Albums Posts: 422	One more before I take off this morning... M8 and Trifid Nebula as seen on June 25, 2011. Taken with an Unmodified Pentax K10D camera using the smc P-A* 300mm f4.0 lens at f5.6. I used an IDAS LPR-2 filter on the lens as well to help reject the inevitable light pollution. Subs were 16 frames of 5 minutes at 400 ISO (1 hour, 20 minutes). Used Losmandy GM8 mount guided by PHD with Orion SSAG on a Stellarvue SV70ED. This image has been a long time coming. I originally captured the lights back in June 2011 and grabbed some darks at the same time as well. However, because the way that the software doesn't like the darks, it was really difficult to remove the amp glow that appears along the edge. After doing all the registration and calibration with darks that are at the same temperature as the lights, I was finally able to bring the FIT file into PI where I worked it over pretty aggressively. As the corners were pretty badly distorted by coma, I've cropped them out as well as the amp glow. This was the last of my efforts with using pef files. I've since gone over to dng.

03-16-2012, 02:47 PM	#250
Ex Finn. Site Supporter Join Date: Nov 2007 Location: Southern Maryland. Espoo. Kouvola. Photos: Gallery \| Albums Posts: 7,975	I was just curious about the Astro-Trac, never seen a picture of it set up with a "heavy" long focal length refractor. I am pretty sure the O-GPS1 will not yield much of exposure time with 900 mm fl. Awesome images from everyone, thank`s for sharing.

03-24-2012, 02:21 PM	#252
Ben_Edict Veteran Member Join Date: Jul 2007 Location: SouthWest "Regio" Photos: Albums Posts: 3,309	Fantastic images here.*I think, I need the O-GPS1 as an easy going alternative to the fully fledged mount and scope stuff. I find all of your images quite encouraging, given, that Pentax seems to be even rarer among astrophotographers, than among the common photog horde. Since the 67 vanished, Pentax has lost out in the skies... Has the comparetively low red sensitivity of Pentax DSLRs improved with the K5? I don't know, haven't seen a diagram of spectral response so far. Ben

03-25-2012, 04:31 PM	#253
hockmasm Veteran Member Join Date: Apr 2010 Photos: Albums Posts: 353	@smigol Great shot of Orion! Man that is such a beautiful photo!

04-05-2012, 11:01 AM	#255
zambonikane Forum Member Join Date: Feb 2010 Location: West Chester PA Posts: 51	Here is a compilation of about almost 2 hours worth of 5min subs of M51. Details of the imaging train are in the link.