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First Light with SharpCap and ASI 290-M Mini

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#1 bdyer22

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Posted 09 June 2019 - 11:22 PM

The first adventure with SharpCap and had a few missteps. smile.gif

 

Bottom line, it's nice and I have a bit to learn.  Compared to SLL 3.3, I think it's more complex, but after a bit of fiddling, it wasn't too hard to get up and running with the live captures.

 

First, I tried to use the PA feature,  detected plenty of stars but could never solve the capture.  This ate an hour and a half of viewing time. I settled for Starsense PA.  Which improves things, but the tracking with Starsense HC doesn't seem to be as good as the original NexStar HC.  Using a polar scope and no ASPA I could track between 30 & 45 seconds with the original HC.  I'm lucky to get 15 now with the Starsense HC.  confused1.gif

 

But it does one great star alignment, and fast too!

 

At the very end of the session, I did figure out why SharpCap couldn't solve the capture.  No plate solver was installed.  ID-10-T error.  UGH... bangbang.gif

 

Thinking about dropping a note to the developer.  The settings know there's no plate solver found.  So it would be nice to have the PA function notify you that it can't find a plate solver. smile.gif

 

The other thing that ate some time was I was going to do some LRGB captures of M57.  And for the life of I couldn't figure out how to do it.  I'm almost certain that I read it can be done, but maybe not for live stacking?  If anyone knows how please point me in the right direction.

 

speaking of M57 here's a comparison between the lodestarX2 and ASI 290M mini on the same scope.

ASI 290M Mini

M57 56frames 448s Mak 127 @ f6
LodestarX2
M57 2019.6.1 00.38.40

 

The other thing that ate a lot of time was trying to run SharpCap in a remote fashion with a mini PC running the scope.  I was using StarryNight Pro 7 and while it didn't appear to be working the little machine over too bad, it was so SLOW.  Click wait 5 seconds.  click... you get the idea.  I'm not sure what it is about the program that bothers me, but I'm not a fan.  It's hard to fathom that this is produced by the same company that built SkySafari.

 

Also tried Cartes du Ciel, while it was more performant, it wouldn't connect to the mount via ASCOM.  (this is probably user error too).

 

Tried Stellarium.  While I want to like it, it's just too hard on the little pc and I find it a bit esoteric and not that user-friendly.  Just my opinion, don't hate me if it works for you. smile.gif

 

Please keep in mind these opinions were largely formed while I was frustrated with things taking 3 hours to get going before the first capture.

 

I installed Celestron's CPWI software after the session.  I think I like it.  It's the fastest, and the easiest to use - practically no learning curve.  As long as you have internet, which in my case isn't a problem, the limited local astronomical DB isn't an issue.  With online access to SIMBAD that crushes that deficiency.  One wish is that it would allow the creation of a virtual port for ASCOM to connect over SkyPortals WiFi.  It's new, so maybe a future feature.  It'd be one less cable. smile.gif

 

In my testing of CPWI, there was no issue with using the HC with the software.  I did a quick align from the HC.  Connected via sky portal to from CPWI and then did a quick align there too.  I found that the mount could be controlled via the HC and CPWI without any apparent conflicts.  NOTE:  I was inside so and didn't do any actual viewing.  I'll confirm this on my next session and see if it can be done with an auto starsense align.
 

It's late, I spend way too much time writing what isn't all that long in the end.  Clear skies and I hope someone finds this useful or at least amusing!


Edited by bdyer22, 09 June 2019 - 11:27 PM.

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#2 Rickster

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Posted 10 June 2019 - 12:49 AM

I know how ya feel.  Some nights it seems like nothing goes right.  And its usually because I tried to make things easier by adding yet another thing I have to fiddle with.  If I make things any easier I may have to kill myself.  tongue2.gif

 

But I think you will really like that 290 mini once you get it all sorted out. It truly is a gem.  I bought mine for an autoguider, and it works perfect for that.  Then I experimented with it in my various scopes.  It worked well in everything but the big scope (not enough FOV).  But if I ever found what I was looking for, it would take crazy good shots. 

 

It worked great for polar alignment when cobbled to a 50mm finder scope reduced to a focal length of 142mm.  Once PA was done, I would leave it streaming as an E-finder.  I was amazed at what it would show in that tiny scope.  All of the Messier objects were recognizable and large fraction of the NGC galaxies.

 

I finally put it back on the autoguider and am now using a DSLR in my Pronto for polar alignment and E-finder.  It works, but not a slick as that little 290MM/50mm.


Edited by Rickster, 10 June 2019 - 12:53 AM.

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#3 bdyer22

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Posted 10 June 2019 - 10:27 AM

Thanks, Rick!

 

I got it last year for some planetary work and to as an autoguider when using the lodestar and vice versa.

 

Hoping to get more scope time this year than last.  I forgot how much fun, and frustrating, it can be. :)


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#4 RazvanUnderStars

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Posted 10 June 2019 - 11:42 PM

One suggestion since you have StarSense. To improve pointing accuracy, use StarSense Manual and use more points during the alignment. I take one every 45 minutes of azimuth. With more data, the algorithm calculating the orientation can do a better job. It only takes few minutes more and you get an improved pointing accuracy for the remainder of the session. CPWI even shows you charts with where the points were and what is the error.


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#5 nic35

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Posted 11 June 2019 - 12:39 PM

With Sharpcap you don't a separate plate solver installation for polar alignment.  It has its own set of images around the pole, and its own algorithm for PA.  But you need to be within 5 degrees of the pole to start, and have a minimum FOV of about 0.5 degrees.

 

Also, the full PA routine is available only in the PRO license.

 

I find Sharpcap's plate solving (the fully functioning one that you install yourself ) to be very useful for centering objects on small sensors like the 290.  When properly configured, it will figure out where the scope is actually pointing, and can be set to slew the mount to your target's location. 

 

I use CdC on my CGEM mount.  Make sure you have the proper Celestron ASCOM driver installed have selected it in the hardware settings.  And that the HC is connected to the computer running CdC through the connector at the bottom of the hand controller.

 

I hope this helps

 

J


Edited by nic35, 11 June 2019 - 12:40 PM.

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#6 bdyer22

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Posted 11 June 2019 - 01:05 PM

With Sharpcap you don't a separate plate solver installation for polar alignment.  It has its own set of images around the pole, and its own algorithm for PA.  But you need to be within 5 degrees of the pole to start, and have a minimum FOV of about 0.5 degrees.

 

Ah, there's a missing piece of the puzzle.  I was nowhere near the pole.  Must have missed that in the directions.  Glad I didn't drop that note to the developer! :)

 

I do have the pro version, but it's a good point.

 

 

I use CdC on my CGEM mount.  Make sure you have the proper Celestron ASCOM driver installed have selected it in the hardware settings.  And that the HC is connected to the computer running CdC through the connector at the bottom of the hand controller.

The other apps were able to connect via ASCOM, but I'll go back and recheck the settings in CdC.  HC was definitely connected via the USB port at the bottom.

 

Thanks!



#7 nic35

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Posted 11 June 2019 - 04:09 PM

BD:

 

Do check CdC.  But I actually meant checking the hardware settings in Sharpcap (SC).  But, this is only important if you want to use Sharpcap to move the mount in RA and DEC, or to use SC for Plate solving.

 

To clarify, if you install a plate solver such as astrotortilla, and the proper index plates, SC runs those programs in the background.  You don't need to do anything to invoke them.  Just click on the proper radio button in the camera copntrol panel and SC takes an image, uses that image and astrotortilla to figure out where the scope is actually pointing and then slews the mount to the position you wanted.

 

If you are not going to use SC for these functions, then no need to enable the mount hardware settings in SC.

 

And, it is not needed for polar alignment.

 

Best

 

j


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#8 bdyer22

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Posted 11 June 2019 - 06:31 PM

Astrotortilla is installed now and the idea of plate solving to center the mount is very enticing on a small sensor and the longish FL of the Mak.  So I'll call that providence. :)

 

Right now, in the process of upgrading the system disk from the internal 64GB eMMC to an old 128 GB SSD via USB 3.  Should be a lot faster, not that it's bad, just too small for win 10.  Not to mention a bit sluggish.



#9 Howie1

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Posted 12 June 2019 - 07:06 PM

I'm figuring that you are not using the polar scope with the AVX. Maybe you cannot see the pole due trees or something? Otherwise you should definitely be within the 5 degree's for SC to do the PA routine.

 

Anyway, I cannot use my polar scope due to herniated disks in neck and back so there's no way I can get down to look up through that sucker. So here's what I do. I've done this with both my CGEM DX and  Skywatcher HEQ5 PRO mount.

 

Do your normal setup, levelling, balancing, and placing into the HOME position. Power up the mount and answer all the usual questions about location and time etc. So nothing diff here.

 

But ... when do start your star alignment, choose your first bright star somewhere near the pole. It can be up to 45 degree's radius away from the pole. Just so long as its selectable in the alignment menu. Centre that first star using the AZ and ALT bolts. Yup the bolts ... not the DEC nor RA buttons! Do not proceed any further with the alignment. 

 

So ... abort from the alignment.

 

Now do the SC PA routine. It will work as you most certainly will be within a few degrees of the pole by having done that first star ALT/AZ bolt adjustment.

 

When you've done the SC PA routine, then just do your normal star alignment on the AVX. 

 

Cheers


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#10 bdyer22

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Posted 13 June 2019 - 09:42 PM

I'm figuring that you are not using the polar scope with the AVX. Maybe you cannot see the pole due trees or something? Otherwise you should definitely be within the 5 degree's for SC to do the PA routine.

...

But ... when do start your star alignment, choose your first bright star somewhere near the pole. It can be up to 45 degree's radius away from the pole. Just so long as its selectable in the alignment menu. Centre that first star using the AZ and ALT bolts. Yup the bolts ... not the DEC nor RA buttons! Do not proceed any further with the alignment.

That's really clever.  thanks for sharing!

 

However, I do use a polar scope for corse alignment.  I mistakenly thought that I could use any star for PA, like ASPA or Starsense PA.

 

The backstory is I had done a Starsense PA on Arcturus first.  I was still seeing tracking issues.  So while pointed at Arcturus, I started the SharpCap PA routine.  That's why I was nowhere near the pole.  :)


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#11 bdyer22

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Posted 13 June 2019 - 10:02 PM

So second light with SharpCap went a bit smoother.  I also opted to use an 80mm refractor instead of the Mak.

 

As expected, SharpCap PA worked as advertised when actually pointed at the pole.  Was pretty easy.  The only real struggle was with the AVX's opposing adjustment screws and central screw needing to be loose enough to allow AZ movement.  Not the best design, but it works.

 

I did do a starsense auto align, then moved the mount to the home position.  connected via sky portal using CPWI and did a quick align.  issued a slew to m57 via CPWI.  It did "work", but was not in view of the camera like I expected.  SharpCap plate solve showed it was pretty close, but CPWI and the HC clearly did not use the same model to point from.  Slewing to m57 via HC put in in view first try.  Though maybe I had something going there.  oh well.

 

BTW disconnecting from SkyPortal causes the mount to stop tracking.  Power cycle and new starsense align fixes that.

 

SharpCap PA, starsense auto align and SharpCap Plate solving is a really good combination.  I'm very pleased. :)



#12 bdyer22

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Posted 13 June 2019 - 10:18 PM

Here are some captures from 2nd light.

 

ASI 290M Mini, 80mm Refractor @ f6

No focal reduction, No filters, AVX mount, no guiding.

SharpCap Software

 

M57

M57 102frames 204s
 
M92
M92 61frames 122s
 
M97
M97 169frames 338s
 
NGC4568
NGC4568 56frames 224s
 
NGC6946
NGC6946 292frames 1168s

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#13 Rickster

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Posted 13 June 2019 - 11:03 PM

Congratulations!  The stars are nice and round and the targets are well centered.  It looks like you have that part well under control.  That should make everything else easier.

 

I think it is amazing what targets the 290 will show with only 80mm of aperture.   Even though NGC 4568 gets kind of lost in what I assume is light pollution, it is easily recognizable.

 

I see that you are using 2 second lights and 4 sec darks.  Could you have taken the lights up to 4 seconds as well and still had a good histogram?

 

Have you tried 2x2 binning yet just for fun?  I agree that 1x1 is a good fit for that scope, but I always got a kick out of how fast the 290 is when binned.   


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#14 RazvanUnderStars

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Posted 14 June 2019 - 06:58 AM

Hi bdyer22,

 

Now that you got PA done, I'd suggest you proceed to read on how to use Sharpcap's histogram controls - by properly setting the black, mid and white levels, you'll get much improved images. Another CN user on the same journey as you recently posted some images, then learnt about the histogram's role and third try was much better.

 

As Rickster suggested, match the duration of your darks with the exposure. What I did was to create a library of darks with 5, 10, 15, 20, 25 and 30s exposures for gains 200, 300, 400, 500 (I use a different ASI camera but the idea is the same). Takes a bit of time but you only do it once.

 

Thirdly, you'll need exposures longer than 2s to show the benefits. The theory on how to choose the best one can get a tad complicated initially (Sharpcap can do it automatically, on the plus side) but even without, try something like 10-15s exposures with a mid-high gain. You'll collect a lot more signal. With an EQ mount you can go even longer, but there's a limit to usefulness, depending on the light pollution in your area. And again, make sure you'll control the histogram to see the benefits.

 

Enjoy!


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#15 Howie1

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Posted 14 June 2019 - 06:09 PM

Great first shots mate! And congrats on getting all the plate solving etc going too.



#16 bdyer22

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Posted 14 June 2019 - 08:50 PM

Congratulations!  The stars are nice and round and the targets are well centered.  It looks like you have that part well under control.  That should make everything else easier.

 

I think it is amazing what targets the 290 will show with only 80mm of aperture.   Even though NGC 4568 gets kind of lost in what I assume is light pollution, it is easily recognizable.

 

I see that you are using 2 second lights and 4 sec darks.  Could you have taken the lights up to 4 seconds as well and still had a good histogram?

 

Have you tried 2x2 binning yet just for fun?  I agree that 1x1 is a good fit for that scope, but I always got a kick out of how fast the 290 is when binned.   

Thanks, Rick!

Yeah, fainter objects are tough from my front yard.  All the neighbors all have 2-3 porch/carriage lights burning and the moon was waxing gibbous ~ 75%. Plus a couple of street lights.

 

Probably could have bumped the exposure up.  I'm still experimenting with the 290 and SharpCap. With SSL 3.3 I would usually do 10-15 second stack of darks and that seemed to work pretty well regardless of exposure time.  Since you and Razvan have brought it up, it sounds like I should create a full set of darks for this camera at various gains. What about at different temps or is that too much?

 

No 2x2 on yet.  I'll have to give it a try :)

 

Hi bdyer22,

 

Now that you got PA done, I'd suggest you proceed to read on how to use Sharpcap's histogram controls - by properly setting the black, mid and white levels, you'll get much improved images. Another CN user on the same journey as you recently posted some images, then learnt about the histogram's role and third try was much better.

 

As Rickster suggested, match the duration of your darks with the exposure. What I did was to create a library of darks with 5, 10, 15, 20, 25 and 30s exposures for gains 200, 300, 400, 500 (I use a different ASI camera but the idea is the same). Takes a bit of time but you only do it once.

 

Thirdly, you'll need exposures longer than 2s to show the benefits. The theory on how to choose the best one can get a tad complicated initially (Sharpcap can do it automatically, on the plus side) but even without, try something like 10-15s exposures with a mid-high gain. You'll collect a lot more signal. With an EQ mount you can go even longer, but there's a limit to usefulness, depending on the light pollution in your area. And again, make sure you'll control the histogram to see the benefits.

 

Enjoy!

I'll do that.  thanks for the advice!



#17 mikenoname

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Posted 14 June 2019 - 09:39 PM

Since you and Razvan have brought it up, it sounds like I should create a full set of darks for this camera at various gains. What about at different temps or is that too much?

 

No, it is not too much. In fact, it is generally a good idea to create darks for every 5 degrees or so as the amp glow and other noise can really increase significantly as the temps go up, especially with uncooled cameras.



#18 RazvanUnderStars

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Posted 14 June 2019 - 10:45 PM

Yes, you should take darks at different gains because you will need them if you take images at those gains. I took them at 200, 300, 400 and 500. Sharpcap automatically picks the closest dark when you change the gain and exposure time. So take them once indoors on a rainy day and you'll use them ever after.

 

To be more precise, you need the same gain, exposure length and temperature. I typically cool to -10C (below it doesn't matter much and cooling too much puts stress on the electronics as you turn cooling on and off). You'll find the theory behind this in many web resources or books.

 

 

Probably could have bumped the exposure up.  I'm still experimenting with the 290 and SharpCap. With SSL 3.3 I would usually do 10-15 second stack of darks and that seemed to work pretty well regardless of exposure time.  Since you and Razvan have brought it up, it sounds like I should create a full set of darks for this camera at various gains. What about at different temps or is that too much?

 




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