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Jack,
There is a chap on Astrobin who considered this same project. In the end he decided that an MX+ would just not cut it, so he bought an MEII see
https://www.astrobin.com/gqpdah/
Side-by-side is really the only sane solution! There are various ways to do this….via Bisque Versaplate accessories or Losmandy accessories.
The imminent MX Series 6 does have an increased payload, from 45kg to 56kg, but, even so, I think two SCTs of that size would warrant an ME.
Getting the OTAs in place and in balance sounds absolutely TERRIFYING to me!!
Martin
I suspect you may need to make a metal base to mount the OTAs on and then bolt that on to the Versa Plate. You may need some balance arms to help balance if you change cameras or filter wheels or autoguider. Its doable though. Probably up to 14″ OTAs – perhaps a RASA and C14.
Martin and Grant,
Thanks for your advices.
It would be expensive and not really feasible.
If you don’t ask you don’t know!
JackHi Jack,
I am intrigued to know what the application is with two similar scopes like this on the same mount pointing at the same target
Cheers
RobinThere is a chap on Astrobin who considered this same project. In the end he decided that an MX+ would just not cut it, so he bought an MEII see
Hi Martin,
at the risk of opening an oft opened can of worms, the quote there
“Interestingly enough, although the C11 has only 60% of the light gathering area of the C14, it has a focal length of 2.79m compared to 3.91m for the C14. It is therefore faster and that varies with the square of the ratio of the focal lengths. Therefore I will end up with a 20% higher signal with the C11”
Is nonsense yes ? (you would get more signal from any target with the C14. it is then just distributed differently on the sensor)
Cheers
RobinNonsense? On the Internet? Never!
The C14 is f/11 whereas the C11 is f/10 so for extended objects he is sort of right but only for sensors with the same pixel size. The same does not apply to point sources since aperture always wins there. Even for extended objects, as you say, the larger aperture will always provide more signal. It is up to you how you distribute that on your sensor. Things were different in the days of film where you didn’t really have any choice in the matter.
Discuss…
The C14 is f/11 whereas the C11 is f/10 so for extended objects he is sort of right but only for sensors with the same pixel size.
Even there, since the C14 image will be (more) oversampled, the images could be filtered to match the seeing (which limits the image resolution here) and then other than some extra camera read noise from the larger number of pixels covered, the two images would contain the same information but the C14 would need less exposure time. I could perhaps even argue that with CMOS sensors the increased oversampling with the C14 might give a greater potential for filtering the non stochastic telegraph noise.
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