Hi. I am about 3-4 weeks away from completing my AP set-up and wanted a little advice please. I should mention that I am new to AP and am jumping straight into the deep end. Please don't advise me to start with a smaller scope or a DSLR. I have made up my mind with the direction I am going in, realize it will be a steep learning curve but I look forward to the challenge.
You're actually not jumping into the deep end. The focal length on the refractor is a bit longer than I'd recommend, but not unmanageable. The mount you've selected will carry it fine.
My first question is given the weight of the Esprit (22lb) and the payload capacity of my mount (40lb I believe), am I better going for an OAG or a guide scope or is the weight negligible?
If I am to get a guide scope, what is a decent one to get?
Once all the gear is added, will my EQ6-R handle the weight? (I also plan on getting a USB Hub and maybe an ASI Air at a later date)
I also plan to do both my capture and processing from my PC indoors via cable link I dont have a Laptop. Am I best to get a auto focuser too and if so, do I need one for the GS if thats the way I'm going?
Are there any other equipment suggestions that will make my life easier with the above set-up?
Thanks for your help
1) I think that a guide scope could work here. The key would be to attach it to the focuser of the 120mm and not to the rings, or the body of the scope, or on a different (ie. side by side) dovetail. An OAG would also work - and probably work better - but the setup would be more difficult. Personally, I would go OAG, but that's because I have many configurations that I use to image and I have my camera and OAG more or less always attached together and move them as a single unit between different OTAs. As for the weight, your EQ6-R won't care either way.
2) If you get a guide scope, one of the 50mm finder-type scopes should work fine. The bonus is that you can usually mount something like this to the finder bracket on your main scope's focuser. Pay particular attention to the focuser and how the camera attaches to it. A non-rigid focuser and a camera connection that is not *rock solid* are two big places where flexure sneaks in.
3) Your mount will handle the weight. As for the ASI Air, I am not at all sold on that platform. I would much prefer a laptop (or NUC, or similar) at the scope. That way you are not locked into a software stack and can run whatever you want. To me, it seems like it's selling point is convenience, possibly at the cost of best results.
4) If you are going to work remotely, even just from inside the house, you want an auto focuser. You won't need one for the guide scope. The guide scope focus needs to be close, but it does not have to be perfect. The guide software will be computing a centroid for the guide star, and this is tolerant of slight focus errors.
As for suggestions to make your life easier, don't try to jump right in to running remotely from inside the house. You *will* need to get a computer out at the scope somehow, because you will be spending a lot of time in the beginning interacting with the gear and making adjustments. The simplest routine example would be focusing. Typically, I would focus a new system by having my software take repeated short exposures. I'd then look at a 4:1 zoom, plus the computed FWHM, on the computer screen while making adjustments. You could not do this from inside the house. Beyond focus, you will likely need to make many other minor adjustments. You'll also want to be at the scope in person, to see how it moves in response to your software's instructions. You do not want to have the mount drive the scope into your tripod or pier, just because you aren't at the scope to see what's happening.
You should only move into the house after you are *completely* comfortable and proficient at running the system through every scenario while you are present at the scope.
Good luck and have fun!