Night Finally Managed a Decent Shot of Andromeda...

Finally Managed a Decent Shot of Andromeda... · 08:30 AM

https://flic.kr/p/zhH854

Might have 'over coloured' it, but after 6 months of experimentation, finally got this from the backyard, with stacking, and PS.

bertwert · 10-08-2015, 08:56 AM

Very Nice!
Maybe slightly 'over coloured' as you say.
But that six months was worth it.

**Ian.morgan** · 10-08-2015, 09:10 AM

Thank you

I think my wife is less convinced

I used an Ioptron Skytracker and K-30 with an old Mitsuki 135mm manual lens, at f4 with about 8 shots of 2 minutes. In fact, many of the shots were through faint cloud, so it came out much better than expected.

I had a couple of 'darks' and 'offsets' and processed the best 75%ish in DeepSkyStacker to produce a Tiff image.

Then opened it in Photoshop CS2 and iteratively tweaked curves and levels according to a tutorial I found somewhere, with 'Annie's astrotools' and a demo of Russell Cromans 'Gradient Xterminator' to bring the colour out. (I overshot a little, but I think it 'kind of works' regardless).

The biggest challenge I find is aiming the damned camera.
Even using astrometry.net to check the aim is tricky as you see very little in the live view, or even in a single test exposure.

bertwert · 10-08-2015, 09:51 AM

Originally posted by Ian.morgan

The biggest challenge I find is aiming the damned camera.

I agree with you there.
My astrophotography is full of fails.
I will get there eventually (maybe).

Danaher Dempsey · 10-08-2015, 10:43 AM

Ian... I am yet to undertake Astrophotography.

I am interested in finding out about the Astro tracking capability of the K3 ii

I have a Lester Dine f2.8 105 mm macro lens ... is that a reasonable lens choice for Astro work?

bertwert · 10-08-2015, 10:51 AM

Originally posted by Danaher Dempsey

Ian... I am yet to undertake Astrophotography.

I am interested in finding out about the Astro tracking capability of the K3 ii

I have a Lester Dine f2.8 105 mm macro lens ... is that a reasonable lens choice for Astro work?

Astrotracer with K-3 ii is the same as other pentax DSLRs with the O-GPS1 unit.
It uses the SR in the dslr to track stars for a short time (Up to 5 minutes)
Here is a review of using Astrotracer on K-3 (should apply to K-3II but won't require the O-GPS1):
Pentax Astrotracer Review: Astrophotography Made Easier - DigitalCameraReview

Lenses for astrophotography should be fast and have infinity focus.
Depending on what FoV you want depends on the focal length of your lens.

Hope this helps!

**Ian.morgan** · 10-08-2015, 03:45 PM

I have the O-gps1 and found that the accuracy was just not good enough for decent shots at least with the K-30.

It was Ok to extend a semi-wide angle such as 28-50mm from a 30s exposure to 90s at low inclination but it didn't really do what I was looking for. (3-4 minutes at 200mm or above).
At ultra wide angles it was also not great as any misalignment was obvious if the wide shot covered the pole star, possibly because the angle of inclination was higher than the range the K-30 can report.

I think the GPS accuracy is fine with the O-Gps1 but the inclinometer of the K-30 is poor which prevents it being really effective.

I also tried piggybacking on a Meade ETX-90 telescope but it is hard to mount the camera securely, and the motor couldn't handle the full weight.

The Ioptron is so much easier to use. There are a few other good similar mounts such as the Vixen Polarie and Astrotrac but the cost/results ratio seemed best for the Ioptron.

With regards to lenses: It's very tricky to know in advance what will work well.

Key points as mentioned are 'fast and sharp' with infinity focus.
Primes tend to be better than Zooms. Old primes are good options.
Make sure the focus and zoom is stiff enough. (It's annoying to have to refocus/rezoom mid shoot)
Look for low CA.
I think full frame lenses are best as you'll be using more of the sweet spot of the lens.
105 f2.8 sounds ok though I don't know that lens personally.

To assist with locating your target:
Upload jpg images to nova.astrometry.net and see how close you are to your target.
If you have an iPad: Use astroplanner to work out what to shoot each night relative to the moon.

The final point : find a dark sky site and avoid moon light! Makes a huge difference.

Ian.morgan
	View full profile
	Contact via private message
	Find other posts by Ian.morgan
	Find threads started by Ian.morgan
	Find threads in which Ian.morgan has posted

10-08-2015, 09:10 AM	#3
Ian.morgan Site Supporter Join Date: Dec 2014 Posts: 152 Original Poster	Finally Managed a Decent Shot of Andromeda... Thank you I think my wife is less convinced I used an Ioptron Skytracker and K-30 with an old Mitsuki 135mm manual lens, at f4 with about 8 shots of 2 minutes. In fact, many of the shots were through faint cloud, so it came out much better than expected. I had a couple of 'darks' and 'offsets' and processed the best 75%ish in DeepSkyStacker to produce a Tiff image. Then opened it in Photoshop CS2 and iteratively tweaked curves and levels according to a tutorial I found somewhere, with 'Annie's astrotools' and a demo of Russell Cromans 'Gradient Xterminator' to bring the colour out. (I overshot a little, but I think it 'kind of works' regardless). The biggest challenge I find is aiming the damned camera. Even using astrometry.net to check the aim is tricky as you see very little in the live view, or even in a single test exposure. Last edited by Ian.morgan; 10-08-2015 at 09:20 AM.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Nature Great Blue Herons - finally some decent shots!	kcmadr	Post Your Photos!	14	04-01-2013 02:37 PM
Finally Bought Some Decent Lenses!	Colorado CJ	Pentax SLR Lens Discussion	13	12-05-2010 12:11 PM
I finally managed to Land one…	Scott Rylance	Post Your Photos!	19	12-14-2008 07:29 PM
Finally a decent sample of the K20D imagel detail. (Portrait)	vitalsax	Pentax DSLR Discussion	4	03-07-2008 03:23 PM
First decent K10D shot!	benplaut	Post Your Photos!	6	01-18-2008 01:04 AM

10-08-2015, 08:56 AM	#2
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173	Very Nice! Maybe slightly 'over coloured' as you say. But that six months was worth it.

10-08-2015, 09:51 AM	#4
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173	Originally posted by Ian.morgan The biggest challenge I find is aiming the damned camera. I agree with you there. My astrophotography is full of fails. I will get there eventually (maybe).

10-08-2015, 10:43 AM	#5
Danaher Dempsey Forum Member Join Date: Sep 2015 Posts: 50	Ian... I am yet to undertake Astrophotography. I am interested in finding out about the Astro tracking capability of the K3 ii I have a Lester Dine f2.8 105 mm macro lens ... is that a reasonable lens choice for Astro work?

10-08-2015, 10:51 AM	#6
bertwert Veteran Member Join Date: Jun 2015 Location: Golden, BC Posts: 15,173	Originally posted by Danaher Dempsey Ian... I am yet to undertake Astrophotography. I am interested in finding out about the Astro tracking capability of the K3 ii I have a Lester Dine f2.8 105 mm macro lens ... is that a reasonable lens choice for Astro work? Astrotracer with K-3 ii is the same as other pentax DSLRs with the O-GPS1 unit. It uses the SR in the dslr to track stars for a short time (Up to 5 minutes) Here is a review of using Astrotracer on K-3 (should apply to K-3II but won't require the O-GPS1): Pentax Astrotracer Review: Astrophotography Made Easier - DigitalCameraReview Lenses for astrophotography should be fast and have infinity focus. Depending on what FoV you want depends on the focal length of your lens. Hope this helps!

10-08-2015, 03:45 PM	#7
Ian.morgan Site Supporter Join Date: Dec 2014 Posts: 152 Original Poster	I have the O-gps1 and found that the accuracy was just not good enough for decent shots at least with the K-30. It was Ok to extend a semi-wide angle such as 28-50mm from a 30s exposure to 90s at low inclination but it didn't really do what I was looking for. (3-4 minutes at 200mm or above). At ultra wide angles it was also not great as any misalignment was obvious if the wide shot covered the pole star, possibly because the angle of inclination was higher than the range the K-30 can report. I think the GPS accuracy is fine with the O-Gps1 but the inclinometer of the K-30 is poor which prevents it being really effective. I also tried piggybacking on a Meade ETX-90 telescope but it is hard to mount the camera securely, and the motor couldn't handle the full weight. The Ioptron is so much easier to use. There are a few other good similar mounts such as the Vixen Polarie and Astrotrac but the cost/results ratio seemed best for the Ioptron. With regards to lenses: It's very tricky to know in advance what will work well. Key points as mentioned are 'fast and sharp' with infinity focus. Primes tend to be better than Zooms. Old primes are good options. Make sure the focus and zoom is stiff enough. (It's annoying to have to refocus/rezoom mid shoot) Look for low CA. I think full frame lenses are best as you'll be using more of the sweet spot of the lens. 105 f2.8 sounds ok though I don't know that lens personally. To assist with locating your target: Upload jpg images to nova.astrometry.net and see how close you are to your target. If you have an iPad: Use astroplanner to work out what to shoot each night relative to the moon. The final point : find a dark sky site and avoid moon light! Makes a huge difference.