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02-03-2013, 01:21 AM   #466
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QuoteOriginally posted by smigol Quote
Always remove any clear filter from the lenses when using them at night for the flare reason. Also, hoods make a great protection from off-axis glare reduction and dew prevention.
I will use a light pollution filter on my lenses when I do widefield, but these are special cases --- and they still produce flare from bright stars.
No filters were used and a hood is always there, though it's a full-frame hood as all full-frame specified lenses. Also I couldn't see any dew on the lens but it is a possibility. Yeah, I read about light-pollution filters but I think that I need to find a good spot instead. I think it's just my lens.

Is my star pic okay? 20s was maximum with the 20mm and I have to go down to F4 to get coma even slightly under control. Feedback is appreciated.

02-03-2013, 07:40 AM   #467
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QuoteOriginally posted by VisualDarkness Quote
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Is my star pic okay? 20s was maximum with the 20mm and I have to go down to F4 to get coma even slightly under control. Feedback is appreciated.
Yes, your star pic is OK - bur you should realize that your image contains much more data than your upload indicates. Almost all astroimages will benefit from some gentle enhancement. You don't need a very sophisticated software, just one that allows you to enhance contrast in a controlled way, using curves and levels.

With your permission I have taken the liberty to play a bit with your upload of Ursa Majoris and enhanced a crop around and below Mizar-Alkaid of your original. Your original is to the left and my enhncement is to the right. (And obviously, with stacking, your potential for successful post-processing will be greatly enhanced).
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02-03-2013, 03:27 PM   #468
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QuoteOriginally posted by VisualDarkness Quote
My best attempt at the Big Dipper and more with K-5 + Sigma 20/1.8
20s F4 ISO640
Two with landscape, note the brutal flare in the sky from lighting.
Man I thought those were UFOs!
02-04-2013, 03:48 PM   #469
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QuoteOriginally posted by Stone G. Quote
Yes, your star pic is OK - bur you should realize that your image contains much more data than your upload indicates. Almost all astroimages will benefit from some gentle enhancement. You don't need a very sophisticated software, just one that allows you to enhance contrast in a controlled way, using curves and levels.

With your permission I have taken the liberty to play a bit with your upload of Ursa Majoris and enhanced a crop around and below Mizar-Alkaid of your original. Your original is to the left and my enhncement is to the right. (And obviously, with stacking, your potential for successful post-processing will be greatly enhanced).
I have to look into it, dunno why I failed to bring out the stars. Maybe my brutal screen fooled me once again? Though I usually go after the histogram. I still don't get that "dreamy sky" look to it but I guess it's impossible with the light pollution etc.
QuoteOriginally posted by Dr_who Quote
Man I thought those were UFOs!
Me too until I realized what it was!

02-04-2013, 08:46 PM   #470
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Latest Orion

Here is one of my latest shots. K-5, Orion ED80mmCF, Atrotrac, 139 second single exposure, pp w/CS5
02-06-2013, 10:33 AM   #471
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Here's the image I took of M78 and area on the evening of Feb. 4th. The skies have been pretty overcast for the past few weeks.

11 x 4 minute
16 x 5 minute
No Flats/Darks/Bias

Camera: Pentax K5 IIs
Scope: Orion 8" Astrograph
Software: PixInsight
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02-07-2013, 03:42 AM - 1 Like   #472
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Marvellous images GWARmachine and Dr_who; almost too good because it is more or less impossible to follow suit with one's more humble achievments. Well, anyway, I haven't had a decent sky since early October 2012 but last Saturday nigth skies cleared intermittently and enough to get a few shots from my balcony in the city.

K-5 image with Tamron SP 350mm f/5.6 (Model 06B) and Pentax GPS Unit O-GPS1:



Orion Nebula: Stack of 12 exposures; 15 seconds at ISO 1250. Click on image to see an approximately 50% crop.

Considering the strong light pollution, I am actually quite happy with the results. More so, as the Astrotracer worked very well with this long focal length and produced nearly no trailing:


100% non-resized crop from the above.

But, as said, skies have been depressingly overcast for months by now. So in desperation, I did an expedition back in my arhives to find some unprocessed images to play with. Amongst others a series of Lyra taken in July 2011 with my K200D, a Tamron SP 300mm f/5.6 lens (Model 54B - not the mirror lens used above) and a 2X SP F Series TC on a Meade LXD75 mount:


The Ring Nebula, M57 in Lyra: Stack of 9 images of 30s and 10 images of 15s exposure time at ISO 1600. Click to see a larger version.

This was also shot under my bright city sky, and it is quite fun to try to squeeze out the last excess photons shining just a bit more than the sky glow:


100% non-resized crop of the above.

And the weatherforecast for the next weeks? Well, fortunately I found out that I actually have many more unprocessed images from 2011 that would deserve a closer look.........

Last edited by Stone G.; 02-07-2013 at 03:54 AM.
02-07-2013, 05:02 AM   #473
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QuoteOriginally posted by GWARmachine Quote
Here is one of my latest shots. K-5, Orion ED80mmCF, Atrotrac, 139 second single exposure, pp w/CS5
A roughly 2.5 minute exposure? I find that hard to believe considering how good the shot is. And it's only an 80mm aperture too. I would love to know exactly how this shot was produced as I've been wanting to buy an O-GPS1 but I suspect that wouldn't get me anything like this result.

02-07-2013, 07:13 AM   #474
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QuoteOriginally posted by bossa Quote
A roughly 2.5 minute exposure? I find that hard to believe considering how good the shot is. And it's only an 80mm aperture too. I would love to know exactly how this shot was produced as I've been wanting to buy an O-GPS1 but I suspect that wouldn't get me anything like this result.
The O-GPS1 alone doesn't do the trick (and GWARmachine uses the Astrotrac which is an entirely different beast: Astrophotography Made Easy - Home). You will need a good lens and a good sky. And to my experiece the limiting focal length that makes sense in conjunction with the O-GPS1 is around 400mm.

Still, if you consider my orion image just above (350mm f/5.6 = 60mm aperture and O-GPS1), taken under a heavily light polluted city sky, you will have a good idea about what to expect under your sky.

I am very happy with my O-GPS1 even though it isn't suited for (small) astronomical telescopes.
02-07-2013, 12:59 PM   #475
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QuoteOriginally posted by Stone G. Quote
Considering the strong light pollution, I am actually quite happy with the results. More so, as the Astrotracer worked very well with this long focal length and produced nearly no trailing:
I found the ring nebula works really well in the city as well as Dumbbell nebula and Orion so far. For the M78 image however I havn't been able to find it in the city, it seems particularily sensitive to light pollution. Probably cause a good chunk of it is dark nebula.

On a side note I came across this by accident, I didn't know Pentax partnered with Borg to make Objective lenses for their telescopes. GG marketing! http://www.sciencecenter.net/hutech/borg/125sd/index.htm
02-07-2013, 02:09 PM   #476
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Was wondering if any of you intrepid astrophotographers used any external power supply on your camera (especially in the cold) - and if so, what works well?
02-07-2013, 02:27 PM   #477
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I am aware of the Astrotrac and have spoken to GWM previously about i. Unfortunately we don't have a 'pole star' here in the Southern Hemisphere that offers easy alignment. Without a permanent observatory setup it'd be difficult to pursue astrophotography on a regular basis. The O-GPS1 seems to be a pretty good introduction to the activity though.

Last edited by bossa; 02-07-2013 at 04:59 PM.
02-07-2013, 05:38 PM   #478
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True Story

QuoteOriginally posted by bossa Quote
A roughly 2.5 minute exposure? I find that hard to believe considering how good the shot is. And it's only an 80mm aperture too. I would love to know exactly how this shot was produced as I've been wanting to buy an O-GPS1 but I suspect that wouldn't get me anything like this result.
Hello Bossa! Yep, 139.2 seconds to be exact. The moon was coming out that night too. I included the original/unedited version of the same picture below. Photoshop can really bring out some great detail. And of course like Stone said, the AstroTrac is very different from the O-GPS1, (which I finally ordered a few days ago, CAN'T WAIT!) Here is my current set up: Pentax K-5, Orion ED80mmCarbon-Fiber telescope, Astrotrac TT320X-AG with TH3010 head (the weights), Manfrotto 410 geared head, Manfrotto 055XPROB tripod, Celestron PowerTank, and sometimes a dark sky.


Big difference from the one a few posts back but this is the same exact image unprocessed.


And a few others just because I haven't posted on here in quite some time. (same night Orion was captured)

(same night Orion was captured)





Also...
QuoteOriginally posted by dbh Quote
Was wondering if any of you intrepid astrophotographers used any external power supply on your camera (especially in the cold) - and if so, what works well?
I am usually out for most of the evening and have never had to switch my battery out. I do make sure it fully charged before I leave too. I know heat is a constant battle with long exposures so other options and experiences are always welcomed here. I found this just yesterday, this website always has some interesting things on it (I know, wrong camera but neat idea) : cheap and easy PSU for Canon EOS
02-07-2013, 05:45 PM   #479
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Couldn't Imagine

QuoteOriginally posted by bossa Quote
I am aware of the Astrotrac and have spoken to GWM previously about i. Unfortunately we don't have a 'pole star' here in the Southern Hemisphere that offers easy alignment. Without a permanent observatory setup it'd be difficult to pursue astrophotography on a regular basis. The O-GPS1 seems to be a pretty good introduction to the activity though.
I couldn't imagine trying to polar align something while down under. Although the polar scope for the Astrotrac does have guide stars outlined in it, I'm sure it still more difficult than in the north. Hopefully you have good luck with the O-GPS1. I should get mine in a few days! Then I'll be posting pics of stars behind ancient Japanese castles,...hopefully.
02-07-2013, 05:54 PM   #480
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QuoteOriginally posted by GWARmachine Quote
Hello Bossa! Yep, 139.2 seconds to be exact. The moon was coming out that night too. I included the original/unedited version of the same picture below. Photoshop can really bring out some great detail. And of course like Stone said, the AstroTrac is very different from the O-GPS1, (which I finally ordered a few days ago, CAN'T WAIT!) Here is my current set up: Pentax K-5, Orion ED80mmCarbon-Fiber telescope, Astrotrac TT320X-AG with TH3010 head (the weights), Manfrotto 410 geared head, Manfrotto 055XPROB tripod, Celestron PowerTank, and sometimes a dark sky.


Big difference from the one a few posts back but this is the same exact image unprocessed.


And a few others just because I haven't posted on here in quite some time. (same night Orion was captured)

(same night Orion was captured)





Also...

I am usually out for most of the evening and have never had to switch my battery out. I do make sure it fully charged before I leave too. I know heat is a constant battle with long exposures so other options and experiences are always welcomed here. I found this just yesterday, this website always has some interesting things on it (I know, wrong camera but neat idea) : cheap and easy PSU for Canon EOS
A quick question if you don`t mind. How is the focuser on the 80ED CF handling the K5`s weight, specially with higher elevation shots.
My EON 120 ED with Crayford is a handful, when pointing higher up.

Cheers.
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