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Photographia Galactica: EAA shots from yesterday


AKB

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Had a great EAA session last night, although the wind was high here, so not the best of conditions, and my attempts at capturing Jupiter with another scope were a disaster.

Here are half a dozen galaxies glimpsed gratefully.  Although these aren't screenshots, they're all just lightly processed with some stretching and a little TLC (I hope) with the backgrounds.   They're quite close to what was on the screen at the time. I'm trialing a 'noise reduction' method that I call ONR for "Olly's Noise Reduction" - a mild flattening of the curve at the bottom end noise threshold, courtesy of @ollypenrice.   Not sure I've got it quite right yet.

Kit: Quattro 8-CF with Coma Corrector on HEQ-5 Pro with Rowan belt mod.  Guided with 60mm guide-scope and PHD2.  Camera is a Ultrastar mono.  All 1 minute subs.

  • M51 - 20 x 1m
  • M64 - 12 x 1m
  • M94 - 2 x 1m
  • M101 - 40 x 1m
  • NGC4631 The Whale - 4 x 1m
  • M63 The Black Eye - 5 x 1m

The longer exposures for M51 and M101 were for when I (a) went in for a cup of coffee, and (2) went in to do the washing up!  Happily, still able to watch the tracking and the images building using VNC on an iPad.

 

58d8251daea81_20170325M5120x1m.thumb.jpg.69e9a868d966d8fb8f4c8e511c5df0e5.jpg   58d8251e3c681_20170325M8112x1.thumb.jpg.60cc49b472da9f2ec0e8ec9ef2a451b1.jpg

58d8251eca264_20170325M942x1m.thumb.jpg.f3752c4c6f86c661fc39dd405f611a43.jpg   58d8251f5f7c2_20170325M10140x1m.thumb.jpg.924317d45d6a3e8f993e0bce0164bbca.jpg

58d8251fef3c1_20170325Whale4x1m.thumb.jpg.8c5d4d94fdf87dbbbf3356e8de9c3def.jpg   58d8251d1f1bd_20170325BlackEye5x1m.thumb.jpg.130a73585f97aa76c473115687e00347.jpg

Thanks for looking.  CC welcome, as always.

 

 

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Great results! M101 in particular has some fine details. I don't think I've seen the 'trailer' faint arm at the right of the image in an EAA shot before.

It looks like the coma corrector was worth using judging by the stars. Have you checked out the coma without it? I have one but rarely use it, but on the occasion I did it definitely improved star shapes at the periphery. Its a compromise between that and shoving more glass in the way.

Martin

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Excellent results!  I really enjoy seeing galaxies in mono.  I did something similar the other night with my Ultrastar M and ES152AR at it's native FL.  Simple, no brainer EAA.

Did you use Starlight Live and it's non linear contrast setting?  I find that works well for galaxies with bright cores.

Don

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1 hour ago, Martin Meredith said:

Great results! M101 in particular has some fine details. I don't think I've seen the 'trailer' faint arm at the right of the image in an EAA shot before.

It looks like the coma corrector was worth using judging by the stars. Have you checked out the coma without it? I have one but rarely use it, but on the occasion I did it definitely improved star shapes at the periphery. Its a compromise between that and shoving more glass in the way.

Martin

Thanks indeed.  Well, I did capture a bit more data than originally intended on M101... I must do the washing up more often!

It was Ian King who persuaded me that the Coma Corrector might be worthwhile - even when using a small chip like the Ultrastar.  I rather chose a Newtonian because of the lack of glass.  If we were blessed with innumerable clear nights, I'd test it out in a heartbeat, but here in the UK it's dire and every moment is valuable.  I'm not entirely happy with the collimation, though, so I have some more work to do there too.

AK

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43 minutes ago, HiloDon said:

Excellent results!  I really enjoy seeing galaxies in mono.  I did something similar the other night with my Ultrastar M and ES152AR at it's native FL.  Simple, no brainer EAA.

Did you use Starlight Live and it's non linear contrast setting?  I find that works well for galaxies with bright cores.

Don

Thanks so much, Don!  Your EAA gallery has been the inspiration for me since starting out with EAA a year ago.  Yes I use StarlightLive (thank you Paul!) and whatever setting looks best!

My goal is to get the fastest EAA rig possible, since, as I commented above, we get so little time here in the UK to actually observe.  I want to SEE things, my eyesight is not the best (astigmatism) so this is the way.  Whilst I feel the pull of the dark (flats, bias, ...) AP side, my photography skills are zilch and observing time is stacked against it.

My ultimate platform would, I think, be either a Hyperstar for my C9.25 or a RASA, but they're a bit heavy (you have experience with both, yes?)  The mount I'd want to use is an Avalon M-Uno.  I just need to know it would be worth the investment.  I think an observatory comes first because setting up, although fun, is a big time-waster.  Any advice welcome.

On the mono vs. colour issue, my first job was in sonar system design.  The people who knew what they were talking about wanted mono, the rest went for colour.  It's just so easy to destroy subtle structure with the polychromatic distraction.  Having said that, a nice colourful AP is usually what wins an APOD, but I think that a really good Ha is hard to beat... pity it takes that much longer.

I'm sure everyone is jealous of your superb location, just spare a thought for the rest of us.

Thanks again.

AK

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Thanks for the kind words, AK. 

I think you would be pleased with a Hyperstar for your C9.25.  I think you're fine weight wise with your eq mount.  Fast optics really helps EAA.  Check the image scale with the Ultrastar to see if it meets your goals.  One downside with Hyperstar is the fixed focal length.  The RASA is very good, but won't give you much more than the Hyperstar and 9.25", and costs a chunk.  Weighs a lot more, too.  It does have a very large corrected field for full frame DSLR's, but the Hyperstar gives you 27mm, more than enough for the Ultrastar.  The HS/9.25" setup can still be used visually or with focal reducers for various image scales at the back end.  The RASA is a single purpose scope with not much flexibility.

You might want to try your Evo mount for EAA as well.  One minute subs might be pressing it, but with Hyperstar and 30-45 second subs, you should get some pretty good results, especially with the mono cam.  Would be a great portable setup.

Priority on the observatory is probably a good idea.  I have the US version of the HEQ-5 mounted on a fixed pier and it is a pleasure to use.  Just takes a few minutes to get going.  No polar alignment needed.  Even though I'm in Hawaii, it can get chilly and buggy outside.  I sit inside with my Mac and extended monitor in comfort.

Let me know if you have any more questions on the Hyperstar.  I'm sold on it for EAA.

Don

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13 hours ago, HiloDon said:

I think you would be pleased with a Hyperstar for your C9.25.  I think you're fine weight wise with your eq mount.  Fast optics really helps EAA.  Check the image scale with the Ultrastar to see if it meets your goals.  One downside with Hyperstar is the fixed focal length.  The RASA is very good, but won't give you much more than the Hyperstar and 9.25", and costs a chunk.  Weighs a lot more, too.  It does have a very large corrected field for full frame DSLR's, but the Hyperstar gives you 27mm, more than enough for the Ultrastar.

Oooh, you're tempting me!  My thoughts and questions include these:

  • image scale: If I'm correct, the Ultrastar on my Quattro gives me 0.64 degrees FOV and 1.66" per pixel on the long axis.  For the C9.25 Hyperstar that would be 0.95 degrees and 2.46".
  • speed / photons per pixel: for the same sampling (and actually, I'd rather do a bit finer?) then there is only a small (x1.33) advantage to the Hyperstar over the Quattro.
  • field: if I wanted to use the 27mm flat field, that's more than twice the Ultrastar's diagonal, I don't know what camera to use.
  • cooling: I'd rather not use cooled cameras for EAA (power requirements and convenience.)  The Lodestar/Ultrastar CCDs are great, but not sure of uncooled CMOS performance for up to 60 sec.
  • focus: I'm assuming that I would need a micro-focuser retrofit, possibly with a motor, as well as the Hyperstar assembly.
  • collimation: I have read widely on the difficulty/ease of collimation and focusing, and am therefore none the wiser.

As you can see, I still have a lot more homework to do.  Advice welcomed.

AK

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AK,

Good thoughts and questions.  Dean at Starizona has some interesting fact sheets on Hyperstar and astrophotography in general.  Based on this article, I never pay attention to "sampling rate".  I try to get the image scale I want and see how it looks with the Ultrastar.  The Ultrastar offers good resolution with pixels large enough to be reasonably sensitive and fast enough for EAA.  Hyperstar is all about speed.  Dean discusses that in the second link.  You should be able to cut your exposures to under 30 seconds to get similar results to your Quattro.  The image scale will be wider, and that's a personal decision on whether that's desirable.  I use everything from a 50mm mini guide scope at 162mm FL to our C11 at prime focus of 2800mm with the Ultrastar.  Depends on the object I'm trying to view.  All have given satisfactory results.

https://starizona.com/acb/ccd/advtheorynyq.aspx

https://starizona.com/acb/hyperstar/whatis.aspx

The 27mm corrected field was designed so DSLR's with ASP-C size sensors could be used.  Anything smaller works, too.  

I'm with you on active cooling.  The dark frame feature in Paul's SLL works great, and he now has a defective pixel removal tool in the later versions.

I don't have a micro focuser on our C11.  I just used a Bahtinov last night for the first time and it worked great.  They have them for Hyperstar setups with a larger hole in the center.  Hyperstar installation and setup is extremely easy.  They do have collimating screws, but I have never used them.  They also have a set of thumb screws that allow the unit to be rotated without disturbing focus.  The assembly is very well made.

Hope this helps.  

Don

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Really excellent captures and some informative discussion. I am reading with interest! Do you think you could get away without guiding? It would potentially accelerate setup time...every little helps to maximise observing time!

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Don

3 hours ago, HiloDon said:

I never pay attention to "sampling rate".  I try to get the image scale I want and see how it looks with the Ultrastar.  The Ultrastar offers good resolution with pixels large enough to be reasonably sensitive and fast enough for EAA.

That's interesting.  You're right, of course, that it's the final result which counts and that does all rather depend on the object you're looking at.  I guess what I'm missing here is experience (so just need more clear nights.)  I'll take another look at those references - I'm sure I must have read them before, but it's been a while.

 

3 hours ago, HiloDon said:

 The dark frame feature in Paul's SLL works great, and he now has a defective pixel removal tool in the later versions.

Yes, it certainly does work well.  Nothing worse than a trail of hot pixels to ruin the delight of an otherwise good image.

 

3 hours ago, HiloDon said:

I don't have a micro focuser on our C11.  I just used a Bahtinov last night for the first time and it worked great.  

Oh really?  That is a surprise.  Coincidentally, I have a Bahtinov mask on order from FLO and arriving tomorrow, so glad to hear that's worthwhile.

Also really pleased to hear how little grief you've had in collimating the system.  Do you often switch from Hyperstar to SCT mode?  It does look to be a very slick operation.

I really appreciate you sharing your experience on this and am more hooked than ever on the Hyperstar concept.  I think that some of the negative press I have read has been from top-notch imagers who have eyes and perceptions unlike the 'rest' of us.  I don't aim to produce that kind of image, but I do want to see things that would be way beyond what an eyepiece can show without taking too much time over it (one reason, in fact, why monochrome is such a good idea!)  The facility to simply capture everything to disk, both screen snapshots and raw files for a little tweaking later, is just great for keeping a record of what you've seen, and to be able to share some of the wonder of it with others.   This is one reason why I like one minute subs - it's not too long to wait, but also not too short to keep running all session long without having to bother to do anything other than remember to change the name of the target in SLL.  I setting up on a new target, I just run in frame/focus mode for a little while at shorter exposures.

I can only hope to produce an image gallery as extensive as yours one day, but I'm going to have fun on the journey.

AK

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3 hours ago, RobertI said:

Do you think you could get away without guiding? It would potentially accelerate setup time...every little helps to maximise observing time!

I tried.  That's why I made the belt-drive mod. But I still find that, with the mount I have, guiding improves the result.  I use the guide scope and SharpCap to do polar alignment, which takes all of 5 minutes, and then PHD2 for the guiding, which if you stick to one area of the sky doesn't need recalibration.  If it does, then it doesn't take long and I can be playing with getting contrast/gamma etc. right on the new target whilst it's doing it.  With guiding, I reject far fewer subs, and that, in fact, maximises observing time by some measure.

My original, personal, definition of EAA was that it didn't use guiding, and I'm sure you can get perfectly decent results without it.  No question.  I'd like to get back to that position, and that 's why my wish-list includes an Avalon M-Uno mount... small PE with very long and smooth timescale.  So even though it's a mount which is advertised as needing guiding (it used not to have a sky model capability, I believe it does now) it seems to me that it is nigh-on perfect for EAA's relatively short subs.

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AK,

I never leave the Hyperstar on, so it's always converted back to SCT.  I can change it blindfolded, usually the case in the dark.  It's as easy as screwing an SCT diagonal on the back end.

I'm with you on the desire to just view the wonders of the universe with decent images.  Don't need anything to publish in a magazine.  I like the one minute or less sub.  Nytecam here was the one who inspired me to get a Lodestar.  It opened up a whole new world.  Paul's software made it possible to do EAA video with a still CCD cam and I am forever grateful, especially for the native Mac version.  The ability to document the observations was also a big plus.  Paul's software came through there, too, by date stamping each image.  I have a permanent record of everything I viewed and what equipment I used.  I get involved with a lot of public outreach now, and this system is indispensable, especially with the remote image window capability.  Most asked question, "Is this a live view from that telescope right there?"

On saving raw files for later processing, SLL right now has the capability to save stacked fits files.  They can't be directly opened in SLL, but they can through DOS or terminal commands.  It is a slick way of trying different settings in SLL.  Hopefully Paul will add a fits open command in the menu in future versions.

One last thing.  I see a narrow band Ha filter in your future.  It's great in LP areas and really improves detail in emission nebulae.  And, there are a lot of them.

Don

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Don

5 hours ago, HiloDon said:

I never leave the Hyperstar on, so it's always converted back to SCT.  I can change it blindfolded, usually the case in the dark.  It's as easy as screwing an SCT diagonal on the back end.

Well, this is excellent news... at least it's something I can practice on cloudy nights!

 

5 hours ago, HiloDon said:

They can't be directly opened in SLL, but they can through DOS or terminal commands.  It is a slick way of trying different settings in SLL.  Hopefully Paul will add a fits open command in the menu in future versions.

Really?  I didn't know that.  Another 'top tip' thanks!  I will give it a go.

 

5 hours ago, HiloDon said:

One last thing.  I see a narrow band Ha filter in your future.

I recently bought a 7nm Baader, but have yet to try it.

I will let you know how I get on with all the above.  Thanks again for your explanations - much appreciated.

AK

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On 29/03/2017 at 02:06, HiloDon said:

Nytecam here was the one who inspired me to get a Lodestar.

Since you mention it (and also reminded by a 'like' here from @nytecam) I have been very remiss in acknowledging his role in firing my enthusiasm for EAA.  I had somehow lost the link to his fantastic Lodestar gallery here:

http://home.freeuk.com/m.gavin/eyelode2.html

so mea culpa, credit where it's due, and a very big 'thank you' to him.

I guess that makes you both my EAA muses!

AK

 

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