12 replies to this topic

[Hexley]

Hi all. Up to this point, I've been using a T-ring and mounting a Sony A7iii camera to my Celestron 6SE telescope, effectively giving my camera a super long lens, I suppose. It's given me very pleasing moon single frame photos and videos, but that's as far as I've taken my imaging. Most of the time I just observe with eyepieces. 

 

I live under Bortle 7 skies, but have Bortle 3 sky about 30 minutes away, so I can get out to decent darkness pretty easily (now and then).

 

Question to you all, would pursuing a Zwo ASI224MC astro camera (or a similar one, like the 385?) be worthwhile for planetary and brighter object observations?

 

My 6SE is on the standard AltAz mount (no polar alignment option) and has a 1500mm focal length, I guess I'd want to pursue the .63x reducer to get a slightly wider view if I'm wanting to view/resolve larger, deep space objects?  

 

Am I way off the mark? I know the 6SE on the standard mount isn't ideally suited for proper imaging, but for EAA, what's the experience like? Can the software compensate for a mount that isn't a typical astrophotography mount? I would love to see more DSO from my light polluted skies, which I suspect the camera would help with.

 

I have a Windows notebook and often use the Celestron wireless adapter to point the scope from my phone instead of using the hand controller.

 

Thanks for any input. I'd like to keep the budget under $500, which covers me for a camera and focal reducer. Curious to get your expertise.

[Maritime]

A flip mirror diagonal is a good place to start....

[jmillsbss]

An alt/az mount is fine for EAA and I've also seen where members can do AP with an alt/az mount because one or more of the stacking and post-capture programs allow the user to perform a field rotation.  That's the reason alt/az mounts have been frowned upon for AP pre-program inability to rotate the field, requiring a full on EQ mount.

 

The focal reducer isn't a question I can answer for the 6SE, but my experience with my C8, I can put in the .63x and a 2" visual back and shoot full frame with my Nikon d5300.  I can't say with the 6SE but it may be possible, more likely with an 1.25" setup.  Someone else can probably speak to that question better than I.  Good luck!

Edited by jmillsbss, 08 March 2021 - 10:36 AM.

[alphatripleplus]

For EAA, some people have had luck with the SE mount, but not everyone. The C6 with a focal reducer will work  with a small camera for EAA on DSOs with SharpCap on an alt-az mount - EAA live stacking software will handle field rotation between sub-exposures, but you will be limited in the length of exposure before field rotation is apparent in an individual sub.

 

 For your question on planetary imaging with an ASI224MC, you should probably ask in the Major & Minor Planet Imaging Forum.

[bips3453]

Live stacking for planetery hasn't reached a good state yet due to high frame rate requirements, as far as I know. Best way for now would be to use live view for observing planets. It looks like that mount should be able to handle that.

Edited by bips3453, 08 March 2021 - 10:58 AM.

[Hexley]

A flip mirror diagonal is a good place to start....

Would you say I'm better off grabbing one of these and continuing to work the planets/moon (perhaps easy targets like M42/M45) with my Sony A7 then?

 

I feel like a $1000+ full-frame camera would be at least as useful as a cheaper ~$100-200 astro camera - but of course, the sensors have very different goals.

[Joey44]

I have a 6SE with the stock alt/az mount, The ASI 224MC camera, and have used it both with and without the .63 focal reducer. It works fine with stacking 10 second exposures in Sharpcap for small DSOs, and even better without the focal reducer for planets. 

The problem is that the small field of view with this setup makes framing objects with the camera impossible, so I have added a flip mirror and this makes all the difference. Alignment visually is needed, and then flipping to the camera if desired. Playing with spacing allows fewer turns of the focus knob.

I had to add a dovetail extension to the OTA in order to move it forward enough for mount clearance. I can get to about 70 degrees this way. The only flip mirror to use, by the way, is the new Baader Flipmirror II. I tried other brands and they were no good and had a longer optical path.

So, you can do some EAA with this setup, but if you want to "view/resolve larger, deep space objects" you really need different scope and camera with a larger sensor.

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[Hexley]

That is very cool, much to consider. Thanks everyone for the input on this!

[roelb]

A 0.5 x or f/6.3 focal reducer with the ASI224MC using SharpCap and plate solving (AstroTortilla) from within SharpCap will do the job.

Bathinov mask for inital focusing using SharpCap.

No need to include a focuser. No risk hitting the mount!

Do use a dew cap.

See here for some EAA examples with a ASI290MM on a 6 SE: https://www.cloudyni...-6-se-asi290mm/

The ASI224MC with a Barlow is also excellent for planetary.

If you later on want do EAA from inside, see here how I started (also applicable for your 6 SE): https://www.cloudyni...ifi-connection/

[rnyboy]

I have a 6se with 385mc and generally having a ball with using a Barlow and a variety of reducer combinations to go from about f/25 down to a somewhat ridiculous f/2.2.  My two favorite setups are just a cheap 0.5x for f/5 and a f/6.3 in combination with that 0.5x to operate at f/3.3.  You get vignetting but the speed improvement is great, and you can crop out the vignetting or correct with flats (which I haven't tried yet) and still get nice images on centered objects that only fill up to about 2/3 of a frame.  I try to find things that fill about 1/2 the frame or so if I can.

 

On the idea of value for the buck and a wider fov I think it's hard to beat a cheap 0.5x reducer for about $30.  Just mount it at the end of the ZWO supplied T-adapter that comes with the sensor and you'll be pretty close to the correct 50ish mm spacing for f/5.  That's a 4x speed increase too compared to about 2.5x with the f/6.3.  The only issues are a bit of vignetting on the 385mc, you'd have nearly none on the narrower 224mc, and you lose the field correction you get with the f/6.3.  

 

I've livestacked/tracked for up to 45 minutes with the SE mount and I'm quite sure I could do an hour if more patient as long as the object fills only the central 50% of the imager or so.  Any drift and field rotation will reduce the tracking time if the object takes up too much of the sensor frame.  I mostly use SharpCap Pro but I do need to branch out to FireCapture because it sounds like it would be better for solar system stuff.  Using 5s subs at a high gain (450 I use) one can get some pretty dim objects.  I have decent images of the Horsehead, Thor's Helmet, and the Leo Quartet which many consider something of a challenge even for larger than 6" scopes.

 

I have the Celestron focus motor so I use the Focus Assit in SharpCap and it does a remarkably good job of achieving focus on stars, planets, and moon.  For DSOs I just focus on a star using the smallest FWHM option or sometimes the multistar(or something like that?) focus option.  

  

Take a look at My Gallery here in CN and you can get an idea of what I've done over a bit longer than a year into this hobby with my 6se, reducers, some filters, and a 385mc in my Bortle 7/8 backyard.

 

I use a Win10 Pro laptop to control the scope and control the laptop via wifi from inside the house with RDP now but TeamViewer before I upgraded the laptop from Win 10 Home to Pro.  Others have used a Windows notebook, so it should work for you.

Edited by rnyboy, 11 March 2021 - 11:17 PM.

[Hexley]

I picked up the 385MC and had "first light" with it last night. I did my star alignment with my illuminated reticle eyepiece on Polaris/Sirius to get it nice and accurate, then I went to work with my camera and SharpCap. Wow, what a fun experience. I have much to learn when it comes to my exposure timing and gain settings, but I'm seeing tons of stuff I had never seen from my Bortle 7 backyard. For anyone with pretty significant light pollution, the camera is a superb eyepiece.

 

My next purchase is a Bahtinov mask to make sure I'm reasonably well focused, although I think I was doing alright when I got Polaris pinpoint sharp (I found Sirius far too bright to know for sure).

[alphatripleplus]

Just a tip on focusing without a Bahtinov - you can use a bright star, but shorten the exposure to a few millliseconds, and zoom in to 200% to 300%, and try to  get the tightest star sizes. (Some people even prefer that technique to using a Bahtinov mask).

[Hexley]

I’ll try this, thanks!