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Hey guys! Its been 8 months since i ve started the hobby of astronomy.I would like to dig deeper now,i am looking for a book in astrophysics that involves mostly formulas and mathematics.With so many books in the market its hard to defferentiate science books from just books with information about the subject
Does anyone have any experience or knowledge about whether it's possible to mount alternative OTAs with a dovetail or rings to the mount that comes with a Celestron Nexstar 80GT? In particular I am wondering about attaching a SW Heritage 130P? I know that Celestron did a 130mm reflecting 'scope on his mount, but it looks to also have that plastic tube clamp, seen on the 80mm image below.
If anyone is looking for a great telescope, I'm selling my NexStar 8SE. It's in great condition, Optics are immaculate and there is only some signs of use on the dovetail bar and the black rim that has faded a bit on one side. The reason that I'm selling is that I'm looking to upgrade.
I had some amazing views of planets and DSO through this scope.... it really is a performer in quite a compact package.
This scope was on a CGEM most of it life so the NexStar Alt-Az mount was hardly used.
I prefer to have this scope local pickup or I'm happy to deliver and even give a tutorial and demonstration of how to use it.. for that reason I'm targeting a buyer around Sydney Australia.
The price I'm asking is $1650AUD.
I have just joined and have been looking around, and putting in various searches to find the answer to my question(s).
I have already found some valuable information, but i can't find a specific answer to a question i have relating to exposure times.
I have shot the milky way several times before, from a tripod and a wide angle lens. I am aware of and understand the "500 rule" and that worked fine for me at first when i was shooting with my Canon 6D Mark II. When i moved over to the Sony A7III i noticed significant trailing using the same rule and that led me to the NPF rule (Via the photopills app incase people dot know).
I am heading back to Tenerife once again in about 6 weeks time and want to buy a star tracker so i can get some really detailed images.
I have done a fair bit of research and in principle, the whole thing doesn't seem to be too daunting or difficult.
I have purchased the Polar Scope Align Pro app so i can align Polaris as accurately as possible, i will practise putting the unit together and familiarising myself with the different parts etc, but it is the exposure times that i do not understand.
My best glass is the Carl Ziess 50mm F/1.4 Planar, the 18mm F/2.8 Batis, the Sigma 35mm F/1.4 Art & the IRIX 15mm F/2.4 Blackstone.
I currently do not own, nor have i ever used a tracker, and I cannot find any information relating to which aperture, ISO and Shutter length any of these focal lengths should or could be shot at.
Is there anything similar to the 500 rule or NPF rule that relates to using a tracker with varied focal lengths? or is it just a case of stepping the lens down for sharpness and then trial and error?
Thanks in advance,
After updating my legacy HC to the 99.22 (I had to, because of the GPS rollover issue) and the MC to the 5.23 firmwares (siply because it was there, and I've got greedy), both acquired via Teamcelestron, my CPC was operating normally until, all of the sudden, its altitude motor stopped working. I've uploaded a video at youtube showing what happens:
As you can see, I don't get any error message in my HC but, if I try to move the scope in altitude, nothing happens (no movement, no motor noises, nothing). When I release the clutch and move the scope manually in altitude, it does move but has a weird noise by the same place where previously it used to make a snap one, which I already reported to celestron tech support once, and even made a video that I also uploaded to youtube:
I've already seeked help from Celestron Tech support (and the folks at Cloudy Nights) but any help from you would be very much appreciated. Best regards,