I'm the original poster. I have listed my scope
look on astromart if you want a deep discount on an AT14RCT
That being said, likely it can be fixed. Just with someone who has more patience, time and access than me. My observatory is 2 hours away and setup for remote imaging. The best evidence I have for this is Astrotech's comments to me. Each mirror set is interferometriclyallywisbang tested. Beyond that the truss setup, mirror cell etc are all very sturdy and adjustable.
Anyway, thought Id post my own personal closure on this issue. Side note Im looking at the 12" GSO Truss newtonian.
Sorry to hear that AT14RCT decision. I googled your ad on Astromart, where you told this:
"In full dislosure I have not been able to collimate it. No matter what I do I can't get my star sizes smaller."
Here comes just a kind reminder for my posts and test images linked above, because I feel sorry if those writings make someone frustrated enough to sell their expensive RCT scope. That was certainly not my intention there...
Techical details from my 10" RCT imaging setup are such, that my imaging scale was deeply in the Goldilocks zone (10" RCT at 0,83" / pixel scale, 0.67 reducer and KAF-8300 sensor, 1x1 bin) compared to average seeing conditions here in Finland. You can calculate your own imaging setup scale easily with the help of this web page: http://astronomy.too...ccd_suitability
If someone wants to compare my test image results with their own RCT imaging setup, then they should always try to get near that 0,83" / pixel imaging scale I have used there in my test images. That's the only way of seeing real differences in actual star sizes between different scopes (supposing seeing conditions are equal foir both scopes). For example AT14 RCT @ 2850mm FL and ASI 1600 Pro camera would need 3x3 binning in order to get similar imaging scale to be comparing similar star sizes with my 10 RCT scope (2x2 binning would be comparable with 0,67x reducer in that AT14 RCT).
But despite of that reducer that's still quite a long FL you will get there from your scope to compete with the existing seeing conditions (compared to my 1340...1400mm FLs used with my 10" RCT).
A kind reminder: please try always to compare "apples to apples" there, when doing such direct image comparisons...
Also please remember, that I have always used short 15...30 second exposures on those test images. Normal deep sky imaging uses much longer sub exposures, which will blur and bloat star shapes in any case.
Longer subs will blur the star shapes quite a lot and I have been doing real DS imaging quite a lot with quite poorly collimated RCT scope too.
(No one will look into image's collimation errors, if someone wants to present nice deep sky photos, especially when the images have been downsized to web size. )
Here's one 1:1 resolution image from my 10" RCT about just before I sold it (I got fed up with the poor imaging conditions here in Finland, which results into only 2-4 finished deepsky imaging projects per season (=autumn, winter and spring in total, no night stars seen here in summer time between May to August):
M27_10_RCT_LRGB_35min_30min_30min_30min_total_2h5min JPG imege there, which tells what kind of image quality could be achieved with that kind of 0.83" / pixel imaging scale with 10" RCT and KAF-8300 sensor (5 min subs there for each LRGB channel for combining that LRGB image in PixInsight).
On the other hand, I can understand perfectly you telling this:
"Just with someone who has more patience, time and access than me. My observatory is 2 hours away and setup for remote imaging."
Free time in our hands and lifes is quite precious and I too wanted to make the best out that time. So I decided doing deep sky imaging was after all not my case of having fun, nor was staying awake in the early hours of morning and trying to collimate and re-collimate my RCT scope (I'm glad, that I did learn the process, but to be honest - it all took way too much time from myself!
So, someone will get from you a very nice 14" RCT imaging scope and I wish you very good luck with the sales process!
Edited by Timo I, 30 June 2020 - 04:16 PM.