Re: large alignment error with polemaster & mach2
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sorry, I tend to write too quickly and my english doesn't really support me :-)
I will try to clarify:
Q:You don't have OTA ready but still get drift in your images? How can you get images if you don't have OTA ready?
A: yes, I friend borrowed me a C8, a Vixen R200, and I have a nikon with a 300m f4. I always had trailed images in dec, field rotation if guiding.
The new OTA is under construction and I am documenting its building here: https://andrealucchetti.smugmug.com/Astrophotography
There is just a page on tube construction for now but I should publish the design page in a couple of days
It is "my project", it will be a 200mm f3,9 corrected newton, corrected over 52mm (carbon tube, zerodur mirrors, Big paracorr, ATLAS focuser)
Given the image scale and the typical sky condition here (over 2 arcsec FWHM), I hope I will be able to avoid guiding without the model.
I know it depends on several factors, mount, ota, etc.
From what I see, in RA I can already get perfect stars in 8-10 min. I said 10 mins to be on the safe side, but probably I could decide for 300s subframes working at f.3.9.
10 minutes is what I used for the 16803 with TEC140, which is f7.
Modeling is something I could do during winter or when I go for two consecutive days, during summer the night is unfortunately too short.
Let's see what I can do, I am ready to guide (MAch2 guides very easily in my opinion)if needed.
In any case I need to eliminate field rotation due to polar misalignment.
Il giorno sab 1 ago 2020 alle ore 22:24 Peter Nagy <topboxman@...> ha scritto:
On Sat, Aug 1, 2020 at 05:51 AM, Andrea Lucchetti wrote: