starting out in SharpCap (ASI294MC on a big dob)

[jonstarrysky]

Hello all, just seeking some pointers before I start out as a newbie both in EAA and SharpCap.

To date I've been using an 18" dob for visual use with Argo Navis / ServoCAT for object finding/ tracking. Now planning to set this up for EAA with a ASI294MC (colour, non chilled), 0.75x reducer/ coma corrector, SharpCap on a 10" Windows tablet mounted on the telescope. Potentially an 8" second monitor. Obvious challenge is the 1.8meter focal length and poor quality tracking. The combo of big sensor + reducer will get me a field of 0.79°x 0.54°. With 2x2 binning I'd be down to an accpetavble 1.4" per pixel.

Aim is to do general live viewing, mainly but not only DSOs, and also to occasionally save image stacks. Moderately light poolluted skies. I am also hoping to use SharpCap "Push-To Assistant" function to help object finding, which TBH isnt great on my ArgoNavis. Argo/ ServoCAT is a closed system, so I would need to look at what SharpCap is telling me regarding degree adjustments required in Alt/ Az and manually get Argo to move accordingly.

Is my 0.79°x 0.54° FOV too small for "Push-To Assistant" ?

Regarding setting up SharpCap....Any thoughts on Regular vs Pro / 32 bit vs 64 bit ?

Tablet is quad core 3.4GHz, 8GB RAM. SharpCap FAQ says 32bit is generally suggested but the ASI294MC is just over 10 mega pixels, which suggests 64 bit.....

Thx, Jon

[admin]

Hi Jon,

long focal lengths always bring a challenge, but your FOV of about 0.8x0.55 should be sufficient for plate solving to work fairly reliably as long as you can get enough stars clearly visible (30+ ideally). This may require some tinkering with gain/exposure settings to get a reliable setup that is also a short enough exposure to give you quick feedback during PushTo. It's worth installing the larger plate solving database if you are using SharpCap's built in plate solving I think.

Nowadays, I recommend the 64 bit version of SharpCap as the default unless there are specific reasons not to (generally only if you have 32 bit Windows or an ASCOM driver that fails in 64 bit).

You would need the Pro version to use the PushTo assistance tool , but as with most Pro features you can try initially to make sure it works for you before purchasing a license - you will be unable to save images after using PushTo in trial mode until you close and reopen SharpCap.

Controlling SharpCap using a touch screen can be tricky, as it is designed for mouse/keyboard use rather than touch - if you can attach a mouse or trackpad at the very least you might find control a lot easier.

Hope this helps,

Robin

[jonstarrysky]

Thanks Robin, Looks like this needs 64 bit and a pro subscription, the push-to assistance tool could be very useful. Hopefully for finding a target its a case of increasing gain / lower exposure enough to see stars quickly (or even with the scope in motion), and then when the target is centered tweak both back for image quality.... To go with the tablet there is a bluetooth mini-keyboard & tiny mouse pad; we'll see how that goes for controlling SharpCap and if something more substantial is needed, and thx noted the software isnt designed for touchscreen