Just starting out with EEVA

[Pixies]

A few months ago, I found myself the owner of a SW AZ-GTi mount.  It was almost by acident, after seeing someone want to swap one with for a AZ5 mount which I had mostly unused. I put the old ST-80 on it and enjoyed mucking about with GoTo for the first time. I have tracking EQ mounts (a Vixen SP and a newer Vixen AP) but only use them for visual.

Anyway, I've always fancied a shot at some EEVA. My back garden is a Bortle5/6 I guess, so although visual works mostly, there are plenty of faint fuzzies I can't normally see unless I go somewhere darker. On a good night, I can JUST make out M33 with averted vision.

So a few weeks ago I came into some extra cash and splashed out on a ZWO ASI585MC - after watching a few posts in other threads, plus Chris' you tube channel. I've also been watching @PeterC65's progress. Hope that doesn't sound like stalking!

 

So last night was my first proper attempt. I had tried a few times to get used to Sharpcap, focussing, live stacking etc. but had never really tried to get a reasonable image before. The equipment I was using:

• ST-80
• ZWO ASI585MC
• AZ-GTi (ALt-Az mode)
• Baader semi-apo filter
• Sky Safari
• Sharpcap 4 Pro

 

I followed a few YouTube vids for guidance on Sensor Analysis and the Smart Histogram. Using a dark area of sky near the zenith I got the following recommendations, setting 15 secs as the max exposure :

Unity Gain: Gain 300, exposure: 3.4s

Max Dynamic Range: Gain 256, exposure 15s.

 

I haven't done anything with darks or flats yet, and there are some colourful hot pixels. Images saved from SharpCap 'as it appeared' with basic stretching

============

M33 (Max Dynamic Range: Gain 256, exposure 15s.)

and with (Unity Gain: Gain 300, exposure: 3.4s)

but I tried a little processing in GIMP on the resultant FITs file for the latter:

Not the best target for an Alt-Az near the zenith, all that field rotation!

 

M1 (messing about with gain 300 and exposure 3.0s):

and finally M37 (Gain 260, exp 4.0s)

 

What did I learn?

Well, at the moment it's a lot less relaxing than visual! Hopefully that will lessen as I get used to things. Alt-Az really restricts things as far as noise goes, with the limited exposure. Plus, it's much harder to find things with such a small sensor! It really requires very good alignment!

I'll look to convert the mount to EQ in time, but can anyone recommend different approaches to Alt-Az that might help?

Any comments or suggestions very welcome.

[StevieDvd]

You did not mention live stacking which SharpCap supports and almost an essential part of a good EAA. 

Have you used/tried it?

There are several EAA videos where Stellarmate/AZ-GTi are used, but people who don't want to get into Linux may appreciate PC astro capture programs which do live stacking.

[Priesters]

12 minutes ago, Pixies said:

Well, at the moment it's a lot less relaxing than visual!

Sounds like you’re on a similar journey to me.  I found EEVA became a lot more relaxing once I got Plate Solving set up.  Quick photo of the stars and the mount moves to bang on target.  Not tried it with my AZGTi in AltAz tho as mine’s on a wedge and works in EQ.  I was a bit worried about polar alignment before I converted to EQ but SharpCap made it super easy and very accurate.  Obviously a wedge is extra cash but I think it’s worth it once you’ve got it all set up.  I didn’t fork out for the ASI Air like many people do with the AZGTi in EQ mode and just use a wired set up with a USB hub.  There’s a really good AZGTi owners thread on SGL if you want more info on all this.

nice pics btw 🙂

[Pixies]

5 minutes ago, StevieDvd said:

You did not mention live stacking which SharpCap supports and almost an essential part of a good EAA. 

Have you used/tried it?

There are several EAA videos where Stellarmate/AZ-GTi are used, but people who don't want to get into Linux may appreciate PC astro capture programs which do live stacking.

Sorry, yes. This was with live stacking 

[PeterC65]

Nice to be mentioned in dispatches!

My first session of EEVA was VERY frustrating but now I really enjoy it. It offers lots of advantages over visual, I can see much more (extent, detail, colour), I can stay indoors in the warm, I can observe faint targets whatever the light pollution or Moon state (this is a big plus I think), and I can take snapshots and share the experience with others. There are also negatives, I often have no idea where the scope is pointing, it could start raining and I wouldn't notice, I feel less connected to the Universe, and so far it's been pretty rubbish with the Moon and planets.

At the start I spent a few days during the daytime wading right the way through the SharpCap User Manual which is well written and explains how to use all aspects of this very capable software. I have analysed my camera sensors but with the 585 (I have the Player One Uranus-C) I pretty much always use an exposure of 4s for DSOs and set the gain somewhere between 250 and 450 with a zero black level. I've found these settings work best by capturing M33 at lots of different settings and then comparing all of the snapshots side by side.

I usually live stack no more than 20 frames as I'm looking for something that is close to real time. I use the live stacking histogram lots and the display histogram hardly at all. I use the auto-stretch feature of the live stacking histogram but usually adjust the colour balance manually. I rarely use the image enhancement features.

Plate solving is like magic! It has made a huge difference to me. I was concerned that it might be complex to set up and you do need to read the manual, but it is worth the effort. These days I never fail to find things and never worry about the alignment of my AltAz mount (I always use the previous alignment and only re-align when I do a visual session). It's worth mentioning that I have a new i7 laptop with solid state hard drives and something that powerful is needed to plate solve quickly (mine does it in less than 10s).

I don't use dark and flat frames (too much hassle, and I don't think the 585 needs them), but I do use Hot Pixel Removal (set it under Prepossessing - Dark Frames). With the Hot Pixel Sensitivity set to 1 this removes all of the annoying RGB artifacts.

I'm still struggling with the Moon and planets as it's not possible to live stack with these targets. I can capture a few hundred frames and produce amazing images the following day in SiriL, but on the night the view is no better than with an eyepiece and worse than with the binoviewer. I have an IR-Pass filter which I've yet to try, which is supposed to cut through atmospheric turbulence so maybe this will improve things.

Another great recent addition which I haven't mentioned so far on SGL is a ZWO electronic filter wheel. I've fitted it with Astronomik filers which are parfocal, so I just focus once at the start of the session and then change filters at will. The ZWO filter wheel is supported natively by SharpCap so I literally just had to plug it in. It makes it incredibly easy to switch filters.

On the subject of focussing, get a Bahtinov mask if you haven't done so already. They make focussing easy and precise which is necessary because it's a harder thing to do with a camera than visually.

One thing I still keep having to remind myself is that EEVA is not about producing AP quality images, it's about seeing more on the night than would be possible with an eyepiece. Fuzzy stars at the edge of the image are not really a problem, nor is the od RGB artefact or satellite trail.

I think I will always like visual as well, but EEVA has stopped me lusting after bigger aperture (for now at least).

 

[PeterC65]

I should also mention my electronics / software setup.

I connect the laptop via a 5m USB cable to a hub on the mount that is powered by the mount battery. From the hub there are shorter USB cables to the camera, mount controller, and now the filter wheel. I control all of these things from SharpCap. It's useful to be able to use the SharpCap mount controls to nudge the scope, and the spiral search is sometimes useful, but mostly you need to have SharpCap control the mount in order to do plate solving with mount alignment re-sync.

As well as SharpCap, I also use Stellarium to GOTO targets and to track them. In order to use two or more software clients to control the mount you need to control it with ASCOM as it can be shared between software clients (don't use Stellarium direct control of the mount). SharpCap starts the ASCOM platform and drivers automatically when you ask it to connect to the mount, Stellarium does not, so start SharpCap first, connect to the mount, and then start Stellarium.

It took me ages to work out a reliable sequence to start the technology!

One other really useful piece of kit is a second, large, monitor. When we bought the new laptop, we also bought a second monitor as the new laptop screen is 16" (down from 17" on the previous one). I'd never used a two-monitor system, so this was also a bit of a revelation. When used with SharpCap I can keep all of the control stuff on the laptop and have the image displayed on the separate monitor, full screen. As well as giving the image more screen real-estate, it also means I can watch the image stacking up while checking for the next target on the laptop with Stellarium.

The second monitor we have is 27" and 4K and the images it displays are amazing. The 4K resolution exactly matches the resolution of the 585 camera so the whole screen is filled with the image.

[Mike JW]

Hi Peter,

Excellent; you are up and running with EEVA. I am sure you will find it useful as your target fainter DSOs to use 10-15 sec subs and maybe do as many as 30 stacks. You are quite right that we loose touch with the universe when we stop doing visual. I will always check where an object is in a constellation and just sit outside enjoying the stars whilst my 30 subs are coming in. I also tend to finish a session by staring at the night sky after I have packed the gear away.

Don't forget that within the 'Reports' section we have quite a few dedicated threads to the various DSO lists so if you do find yourself doing an object where there is a thread, then just add it in. See below for the current list.

Mike

List of SGL threads.docx

[Davesellars]

Looks like a good start!  I'm just starting down the EAA route myself although it's not replacing visual...  it's more like a different tool to use.  I'm still learning and don't have the luxury of a goto mount at the moment but from my previous AP experience, platesolving will solve all your issues and it's dead easy to setup and connect through SharpCap (I installed ASTAP).