Portable Imaging Setup - ideas welcome!

[JohnH]

Hi,

I am looking for advice and suggestions on components for a new portable imaging setup to match my Skywatcher adventurer. My main interest is to use this for widefield shots of DSOs not solar system objects. Visual use is secondary.

I have a WO 66ED currently but the scope suffers from blue halos on bright stars (it is only a doublet) and I really do not like that. I have been using a mirrorless DSLR (Olympus OMD EM5) with it which is ok but lacks Ha and has limits in use with long exposure (>60s) sequences not possible. The SLR will continue to be the grab and go option, nightscapes etc

BUT

For serious, guided imaging I am looking for a lightweight, high quality optic and a cooled camera to match the SA. The equipment will see use in a red zone (home) as well as traveling (dark skies).
I have had 2 thoughts - a mono system plus fw and filters - this will allow me to use NB at home plus LRGB is a bit more tolerant of light pollution
or
OSC plus AO from Starlight, here the AO will allow me to negate guiding issues from the Adventurer (no DEC compensation, PE) and offset the lower sensitivity.
I already have a Lodestar X2 for guiding the SA.
For the OTA I have thought


WO Star 71
WO Spacecat 51 - but focus/tilt issue concern me.
Stellarvue SVX080T-R (too much scope for the SA?)
????

For the camera I am hoping to use APSC or 4/3 sensor size and probably either ZWO (value but driver issues?) or Starlight (for best integration with the AO/OAG) considering:

Trius sx-814
ASI 294 MC
??


Or you might have better ideas...the budget is flexible (but not infinite) I am happy to say.

One other point - using a cooled camera in a portable setup is going to require a fair bit of power. Any suggestions you have for portable power options would be appreciated. The Tracer products look good but not sure if there is an AU distributor.

I know that is a lot of questions...

[The_bluester (Paul)]

I have an SVX80T-3SV (Not the carbon one) and I reckon it would be too heavy for a Star Adventurer. I am using it with an ASI294 too, I have an ASI2600 on the way with the 294 to be retired to my SCT where it suits the image scale better. I have mine on an Orion Atlas Pro AZ-EQ (AZEQ6 in black pyjamas, basically no difference other than the paint) which carries it with ease. I reckon the whole rig (Scope, focus motor, flattener, OAG, guide and main cam) would be maybe 8KG, but I have never weighed it.


I shot these with that combination, the one around Antares is two panels. As always, mostly they could use more data!

https://www.astrobin.com/full/xpuc7b/0/
https://www.astrobin.com/full/5qg6os/0/
https://www.astrobin.com/full/stjvr9/B/

[Camelopardalis (Dunk)]

Yeah I’d have concerns about focal length (and weight) beyond a space cat. A larger scope is not really what the Star Adventurer was intended for.

With good polar alignment and RA guiding you might do just fine, but it could turn out into a frustrating experience.

With the right camera, there’s lots of satisfaction to be had at shorter focal lengths, well within the comfort zone of the SA...

[JohnH]

Dunk, Paul,
I know I am pushing this BUT I intend to use this setup in 2 modes, with an SLR and 50mm or 150mm F2.8 prime lens unguided for widefield AP when traveling.
2nd mode is the one I am talking about, a scope for AP/visual use at home or at dark sites that is better than my current WO 66 SD (which the mount can handle).

I am not a novice at this, my last setup was a 10" GSO RC on a G11 with an SBIG 2000xm ccd but I sold that when sent overseas. That gear was fantastic but is too heavy for my current purposes.

On further thought it seems to me the SpaceCat really is not really a candidate - it is not a visual scope (I think a visual back is available but really not much use I think??) it has been reported as having focus/tilt issues and even some optics issues, it is smaller than the 66 I already have etc etc and finally my Olympus PRO lenses are probably as good/better. The only plus is the true APO/FF nature of the scope (the Star 71 shares the same design).

A WO Star 71 seems to fit the bill well, it and the Stellarvue CF are both about 2.5 Kg and the imaging train I have in mind is about another 1.5 Kg. The Stellarvue requires a flattener etc so pushes the limit, so the WO is my first choice for now.

My plan is when using the scope for AP tracking will be enabled to compensate for the longer FL of the scope, if I use OSC with the SX AO option then the lack of dec correction is also fixed...

[Camelopardalis (Dunk)]

I’m confused, John...are you looking to get two new rigs?

[JohnH]

Dunk,


Sorry to confuse, one set up but two use cases:

1. Oly SLR/PRO Lens and no tracking etc. For widefield and air travel cases. This I have sorted.
2. Home and road trips. APO scope (2.5Kg or less), guided, cooled CCD but used in both red zone (home) and dark skies (away). Secondary desire is to use the OTA for visual.

It is the second of these cases I am seeking ideas for, both the OTA and imaging train, the objective of being to be able to go longer than 60s (300s?) and image somewhere about 400mm fl.
I have a WO 66SD and flatener currently left over from my previous setup. I am looking for something that give significantly better results for AP that that. While the field is flat and the fl is ok it has CA issues.

John

[Camelopardalis (Dunk)]

No worries, I’m easily confused

For scenario 2, might I suggest the AZ-GTi? Same payload, about the same size and weight, but both axes are motorised and therefore guidable, and the world of plate solving onto your target becomes available.

I drive mine using an el cheapo 15000mAh power tank with a Jaycar USB to 12v adaptor (although there is a slot for 8x AA batteries). The AZ-GTi specs quote maximum of 750mAh. I use an Intel NUC running SGP but you could use something lower power such as a RPi or ASIAir. (To be fair, my wide field NUC is Atom based and draws all of 1-2W).

Scope-wise...I have a WO Z61, and it’s well corrected and not overly heavy...I think WO have put their scopes on a diet the past few years but they still feel well made. The 61 might be a bit short/slow for your needs, but a mate has the Z73 and loves it. WO also do a 0.8x reducer for these scopes to speed them up a bit. There maybe a cheaper solution, but WO make a nice scope IMO.

FWIW, I’ve not imaged beyond 200mm with my AZ-GTi yet* but after DARV polar alignment it was guiding with ~2” rms error. Last week, when we had some clear nights, the mount was happily guiding 3 minute subs, and (because of the focal length) they were largely inseparable in Subframe Selector. I didn’t take longer subs as I didn’t need to with my camera.

Hope that helps...and I didn’t get too confused

* technically this is incorrect...I’ve mounted my C6 SCT on the mount and used it for lunar imaging