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A version of “evscoping” for my 8” SCT?

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#1 cpl43uk

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Posted 01 October 2020 - 09:47 AM

Hi everyone. Apologies for such a naive question but.....

 

I have limited interest in astrophotography, being a visual observer and sketcher but i am getting frustrated by the difficulty in seeing targets from my surburben environment. I have an 8” SCT on an AVX and i feel i have covered most of the popular targets for my scope from my garden over the years and really i’d like to see more of the faint fuzzies and nebulae etc.

 

I could upgrade to 9.25 although my AVX might be a concern (i like to use binoviewers) and so ideally i would love a ccd camera to pop into the diagonal (plus barlow etc) and show an image on my ipad that i use to control the scope, imaging as it builds up a live stack. In that way the merest hint of a faint fuzzy might improve to be a little more and i will find a whole new suite of objects available on my set up. I surely cannot be the only observer for such a market?

 

Evscope seem to head in that direction but i already have a good set up and wish to augment. Instead i see much about ZWO cameras and AIR/Studio which seem to get there but are configured more for astrophotography capture and later processing. 

 

any thoughts?



#2 Forward Scatter

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Posted 01 October 2020 - 10:10 AM

i Chris

 

What seems to fit your bill is definitely EAA. There are heaps of threads on this forum that discuss exactly what you are looking for, and a lot of EAA practitioners use ZWO CMOS cams with ASIAir and love the combo due to its simplicity and performance.

 

The major question then would be budget in regards to cooled/uncooled cameras. Whichever camera route you proceed with, you'd most likely not be able to use diagonal as the camera will have a different focus plane than the eyepiece. And for the 9.25, and rather than a barlow, you would need a focal reducer (f/6.3, 0.5X, or 0.7X) to fit most of the DSOs onto the image and facilitate platesolving.

 

If you would want to image and control the scope on a PC, Stellarium and Sharcap pro are way fun too. 

 

Looking forward to your EAA images!

 

Cheers!


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#3 garyhawkins

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Posted 01 October 2020 - 11:04 AM

Hi everyone. Apologies for such a naive question but.....

 

I have limited interest in astrophotography, being a visual observer and sketcher but i am getting frustrated by the difficulty in seeing targets from my surburben environment. I have an 8” SCT on an AVX and i feel i have covered most of the popular targets for my scope from my garden over the years and really i’d like to see more of the faint fuzzies and nebulae etc.

 

I could upgrade to 9.25 although my AVX might be a concern (i like to use binoviewers) and so ideally i would love a ccd camera to pop into the diagonal (plus barlow etc) and show an image on my ipad that i use to control the scope, imaging as it builds up a live stack. In that way the merest hint of a faint fuzzy might improve to be a little more and i will find a whole new suite of objects available on my set up. I surely cannot be the only observer for such a market?

 

Evscope seem to head in that direction but i already have a good set up and wish to augment. Instead i see much about ZWO cameras and AIR/Studio which seem to get there but are configured more for astrophotography capture and later processing. 

 

any thoughts?

Chris,

 

You practically have everything you need to get going with a good EAA setup.  Stick with your AVX and C8 SCT.  Buy a decent sensor - 385MC, 178MC, 183MC, 294MC, or 533MC depending on your budget.   You'll ideally need a 0.63 focal reducer but it's not essential to start.  You can see what you'll likely to achieve here, https://youtu.be/8zmeUPo2xas -  if this matches your expectations you're good to go.

 

CS Gary


Edited by garyhawkins, 01 October 2020 - 11:05 AM.

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#4 GazingOli

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Posted 01 October 2020 - 12:26 PM

Hello Chris,

 

you will love EAA - definitely!

 

I would recommend the ASI 294 - the image scale is a decent choice for the C8 and it is very sensitive. Also the field of view is wide enough which is important for the live stacking because for live stacking the software (e.g. SharpCap pro) will need to detect enough stars to align the images when stacking. I used to start with an ASI 224 which is a great camera but the FOV is too small and so I ran into the problem that live stacking did not work all the time. The ASI533 is a good choice for your scope as well.

 

Anyway: have a look at my gallery and you will see what you can expect. And I am really a beginner - just started in April this year with EAA.

 

It is really worth having a look at Gary's video. Gary is explaining the entire process very well and you can see how everything works!

 

CS.Oli


Edited by GazingOli, 01 October 2020 - 01:07 PM.

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#5 Forward Scatter

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Posted 01 October 2020 - 03:08 PM

Definitely welcome to a way cool and fun aspect of astronomy!
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#6 chilldaddy

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Posted 01 October 2020 - 11:14 PM

Chris,

 


 Instead i see much about ZWO cameras and AIR/Studio which seem to get there but are configured more for astrophotography capture and later processing. 

 

 

The ASIAir may be ideal if you want an all-in-one solution for use with an iPad.  Yes, it is capable of capturing for AP and post processing, but it is also very capable for live stacking and is popular with EAA enthusiasts.  Take a look at this excellent overview from Agena of the product.

 

The other popular route is a PC at the scope running SharpCap.  You can then remote into that computer from inside.  It is Windows only though so you can continue to use your iPad for scope control but would need a PC for viewing.  I have done that as well but eventually switched to Stellarium for GoTos so all software is on one computer. 

 

There are options, so take a look at what will work best for you and welcome to the club!  Also, be prepared to find your eyepieces getting neglected.  The color and detail are phenomenal compared to visual and I rarely touch mine anymore. smile.gif

 

Greg


Edited by chilldaddy, 01 October 2020 - 11:15 PM.

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#7 alphatripleplus

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Posted 03 October 2020 - 10:05 AM

In addition to SharpCap, which  works only under Windows, you might also consider ZWO's free ASILive EAA software (part of ASIStudio) which runs on either a Windows PC or Mac and should work with any of the current ZWO cameras. ASILive is targeted at EAA not AP.

 

However, I don't believe you can run it directly on an iPad.

 

ASILive on a PC or Mac offers similar features to the livestacking software on the ASIAIR, although there are other software tools that the ASIAIR offers (like guiding, PA alignment, guiding etc). 



#8 cpl43uk

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Posted 04 October 2020 - 08:33 AM

Chris,

You practically have everything you need to get going with a good EAA setup. Stick with your AVX and C8 SCT. Buy a decent sensor - 385MC, 178MC, 183MC, 294MC, or 533MC depending on your budget. You'll ideally need a 0.63 focal reducer but it's not essential to start. You can see what you'll likely to achieve here, https://youtu.be/8zmeUPo2xas - if this matches your expectations you're good to go.

CS Gary

Thanks to all who have posted.

Gary I watched your YouTube. Wow -simply fantastic outreach and I watched the full 90 mins transfixed. My own Astrosoc are only now dabbling in such thinking ahead of our UK National Astronomy Week and boy is this a great example! I even understood the accent

So I have a few very simple follow ups from your session vs my situation...

Firstly I plan to continue visual observing - I mainly use the 8" for binoviewing and sketching. How realistic is it to remove the star diagonal and binoviewer and add the camera/live stacking "on the fly" during a night of casual observing or is it "one or the other" for each such session? I am thinking here of setup preps etc.

Next you used a finder scope and then plate solved. I plan to keep my StarSense as the main route for auto set up since (as I said) some nights I will just be visually observing. Can I set up via SS and just use the camera from then? My alignments can be variable depending on how I set the scope pointing to Polaris (as a guess since I cannot see it from my house) but the targets are always found in a 40mm eyepiece and often the 20 mm. I then realign using the SkySafari app on my iPad and move on from there. Could I just switch over to the camera and plate solve thereafter (I know ASIAIR has its own polar set up routine but can I just skip that bit?)

You used flats and darks. Are these set up every night or do you do this once for the camera and file them away?

You had the targets in focus as you started out. Had you done the focussing on the viewfinder star first? Can you just tweak the focussing during your go-to observations?

You were anxious about meridian passages. I never worry normally - I am next to the scope and keep an eye on things although pointing can sometimes be a little off. Is this why you were worried?

Does balance of this extended set up (especially if filters or a Barlow is adding into the chain) require any weights on the scope itself? Like you, I have the 8" SCT on the AVX? Attaching barlows all straightforward with such a set up?

Planets. I realise each camera has its main domain to work in but if you had slewed to a planet the other night, what might you have needed to do? Basically more mag and so you have to add a Barlow.? This again can be done of the fly or do you need to decide it DSOs or Planets for each session?

What was crystal clear to me was that this technique allows that extra detail to nail the target, especially (for me) nebulae and the fainter galaxies. I guess I am not yet convinced I'll move into astrophotography so black and white might be sufficient for my needs? Any visual detection advantages (beyond the view) between equivalent mono vs colour? Might mono be better for detection vs colour for presentation?

But as I said my grateful thanks to you and the group...

Edited by cpl43uk, 04 October 2020 - 11:55 AM.


#9 garyhawkins

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Posted 06 October 2020 - 04:57 PM

Hi Chris,

 

I'm glad you enjoyed the livestream - the accent as you might have guessed is from the West Country.

 

The primary difference between your visual and imaging setups is going to be your focus point.  Thus, so long as you have everything to hand and can refocus you'll be fine switching.  It may not be practical to switch back and forth multiple times unless you can set both visual and imaging up with a flip mirror, but I've no experience of this to know whether it's practical.

 

I plate solve with the image collected from the C8.  The finder scope is there really just to give the audience a sense of some of the observing difficulties I face from my location.  It is also helpful when I'm remote operating the rig, and sitting inside nice and comfy.

 

Yes you can setup with Starsense and then start imaging.  Are you using the CPWI software from Celestron?  If not, consider doing Starsense through this when imaging.  Sharpcap Pro ($15/year) has an excellent polar alignment tool built-in.  Use this and your polar alignment will be accurate to an arc minute or so.  With platesolving you basically remove the need for multi-star alignment.  All I do is ensure I've got good polar alignment (using SharpCap Pro), then Quick Align (which is basically skip alignment) in CPWI.  I then slew the mount at a target, if the mounts within 15 degrees (which it will be), then platesolve through SharpCap (calling the All Sky Plate Solver) is precise.  The target will appear right in the center of the screen when the mount corrects its position.

 

I use darks and flats.  These are stored in a folder.  I use these until I change the optical chain.  I capture these using the appropriate SharpCap tools.

 

I setup focus at the beginning of a session with a Bahtinov Mask - again SharpCap Pro has a tool to help with this.  If I feel I need to refocus mid session I just pop the mask back on.  However, I find the C8 holds focusing without issue.

 

I seldom Meridian flipped when I was using the pointing model in CPWI, as I found pointing accuracy was much less (and outside my 0.5 degree FOV) on the flip side.  Now I plate solve I don't worry any more.  I just neutrally balance the OTA and away I go.  Now the only problem with flipping is the occasional cable snag but that can be solved with better cable routing.

 

I do not have to weight the OTA to achieve declination balance, I have a long enough dovetail.  I too use an AVX mount.  I do use two counter weights, as I prefer the more central position of two weights compared to the practically-off-the-end position of one weight.

 

For planetary imaging I remove the focal reducer and add a Barlow.  Thus, DSO and planetary imaging sessions don't really mix unless it's a long evening and you have time to make all those changes.  I might even change out my 533MC for a 224MC as I get a faster frame rate with the latter, even if I use ROI selection with the 533.

 

I personally like color, particularly for outreach.  However, mono imaging works well for galaxies, and I'm also just about to experiment near IR imaging (850-1100nm only) so even though I'm getting RGB from the 533MC I will just display in B&W.  A dedicated mono camera will offer greater sensitivity so it might be a better fit for you.

 

Hope I got all or most of your questions - happy to answer any others you have.  Great to see people getting into EAA and enhancing their astronomy experience.

 

CS Gary

 

PS: I wonder if my friend, Ross, will participate in Astronomy week - he runs Bolton Astronomical Assoc.

 

 

 

 

 

 

 

 

 

 

 

 

Thanks to all who have posted.

Gary I watched your YouTube. Wow -simply fantastic outreach and I watched the full 90 mins transfixed. My own Astrosoc are only now dabbling in such thinking ahead of our UK National Astronomy Week and boy is this a great example! I even understood the accent

So I have a few very simple follow ups from your session vs my situation...

Firstly I plan to continue visual observing - I mainly use the 8" for binoviewing and sketching. How realistic is it to remove the star diagonal and binoviewer and add the camera/live stacking "on the fly" during a night of casual observing or is it "one or the other" for each such session? I am thinking here of setup preps etc.

Next you used a finder scope and then plate solved. I plan to keep my StarSense as the main route for auto set up since (as I said) some nights I will just be visually observing. Can I set up via SS and just use the camera from then? My alignments can be variable depending on how I set the scope pointing to Polaris (as a guess since I cannot see it from my house) but the targets are always found in a 40mm eyepiece and often the 20 mm. I then realign using the SkySafari app on my iPad and move on from there. Could I just switch over to the camera and plate solve thereafter (I know ASIAIR has its own polar set up routine but can I just skip that bit?)

You used flats and darks. Are these set up every night or do you do this once for the camera and file them away?

You had the targets in focus as you started out. Had you done the focussing on the viewfinder star first? Can you just tweak the focussing during your go-to observations?

You were anxious about meridian passages. I never worry normally - I am next to the scope and keep an eye on things although pointing can sometimes be a little off. Is this why you were worried?

Does balance of this extended set up (especially if filters or a Barlow is adding into the chain) require any weights on the scope itself? Like you, I have the 8" SCT on the AVX? Attaching barlows all straightforward with such a set up?

Planets. I realise each camera has its main domain to work in but if you had slewed to a planet the other night, what might you have needed to do? Basically more mag and so you have to add a Barlow.? This again can be done of the fly or do you need to decide it DSOs or Planets for each session?

What was crystal clear to me was that this technique allows that extra detail to nail the target, especially (for me) nebulae and the fainter galaxies. I guess I am not yet convinced I'll move into astrophotography so black and white might be sufficient for my needs? Any visual detection advantages (beyond the view) between equivalent mono vs colour? Might mono be better for detection vs colour for presentation?

But as I said my grateful thanks to you and the group...



#10 cpl43uk

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Posted 08 October 2020 - 02:03 PM

Thanks again Gary. So - nearly there.

 

On the set up as I indicated I uses Star Sense auto align and then drive the scope afterwards with SkySafari on an iPad mini. (I have a mount position marked out based on my best guess for Polaris). Sometimes the target is only in the 40mm eyepiece rather than the 20mm -If so I add a few more alignment stars which seems to improve it. All straightforward when you have visuals and a nice wide field of view! I frequently "realign" on the fly within SkySafari.

 

I had therefore assumed I would perform this ritual and then remove the visual chain and replace with the camera chain. Of course the balance might be now be off (just realised) but I don't use a laptop so do not have CPWI. Since I cannot see Polaris from my patio it has bee a concern if these devices require it before functioning. However if this is not a problem then it's now simply a choice of which camera, which attachments and the ASIAIR to through it to the iPad...  and entry into the world of EEA!



#11 garyhawkins

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Posted 08 October 2020 - 08:10 PM

Hi Chris,

 

I believe the ASIAir has a plate solver built-in, so you should be able to use this (assuming the ipad talks to it) for accurate repositioning after slewing into the general region of the target if it's outside the sensor FOV.  Otherwise, I'd use a cheap laptop (I use a $300 i3 HP) and this will drive everything.

 

CS Gary

 

 

Thanks again Gary. So - nearly there.

 

On the set up as I indicated I uses Star Sense auto align and then drive the scope afterwards with SkySafari on an iPad mini. (I have a mount position marked out based on my best guess for Polaris). Sometimes the target is only in the 40mm eyepiece rather than the 20mm -If so I add a few more alignment stars which seems to improve it. All straightforward when you have visuals and a nice wide field of view! I frequently "realign" on the fly within SkySafari.

 

I had therefore assumed I would perform this ritual and then remove the visual chain and replace with the camera chain. Of course the balance might be now be off (just realised) but I don't use a laptop so do not have CPWI. Since I cannot see Polaris from my patio it has bee a concern if these devices require it before functioning. However if this is not a problem then it's now simply a choice of which camera, which attachments and the ASIAIR to through it to the iPad...  and entry into the world of EEA!




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