Quote:
Originally Posted by JA
I wouldn't bother with other lenses or scopes- At the 300mm focal length the Canon 300mm 2.8L would be excellent. If you need a tiny bit more focal length, say around 400mm, then get one of the Canon 1.4X teleconverters/extenders for very little image quality loss. All you need to do is to mount your guidescope (you don't say which) together with your camera (you don't say which, but presumably DSLR) on to a common mounting rail that can be held by your mount (you don't say which mount). In any event the mounting rail /plate will most likely be either of the Vixen or Losmandy style dovetail.
Use the lens tripod collar thread to screw the lens/camera combo on to the dovetail mounting plate and then do the same for your guidescope, except that you may need some guidescope rings etc, to help you mount and aim the guidescope. At a guess a 11 or 14 inch (common mounting plate lengths) mounting plate should suit your situation, although I would try to select the shortest plate to suit your gear to minimize overhang and center the mass better. That should get you started.
In the spirit of a complete answer, If you want something different, It may also be possible to mount the guidescope to the lens by dispensing with the lens tripod collar and replacing it, if you are lucky enough to get the exact size, with a rigid telescope mounting ring which also has some top screw threads for potential guidescope mounting. Also possible, and i've seen it done. but somewhat flimsy and I wouldn't recommend it, would be to mount ( a tiny) guidescope to the camera hot shoe.
Also to help extract the most out of your 300mm 2.8L lens it would be good if you have one of the newer model fullframe 5D cameras or 6D.
Best
JA
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I prefer if there are links or images f what you are talking about, as i am trying to imagine what you are talking about and i feel i couldn't get it.
Beside my Canon lens, i do have the following setup or equipment i will use for imaging:
Mount: Skywatcher AZ-EQ6
Camera for imaging: QHY163M [so no DSLR]
Guide scope: either ST80 or ZWO 60mm
Guide camera: QHY5L-II-M, i do have ZWO ASI385MC for planetary, can be used here too.
Filters: 3rd party LRGB and Optolong NB [Ha/Oiii/Sii] filters all at 36mm size inside 7x36mm QHY filter wheel
I am using EQMOD rather than Hand controller and still have some problems to perfecting my polar alignment, but all told me to do that which i am almost close using Polemaster, and just last time night i started to use stars alignment as many recommended me to use it to get to targets better, and also last time i tested guiding again as i wasn't good in using it in the past once or twice, i got targets i wanted but they are all noisy and not pinpoint stars and let's say bad amp glow with OIII exposures as i was using higher gain, but i do live in light pollution area anyway.
So i want a scope or lens that i can depend on for all filters if possible and not Achro that will force me only for NB, and also for focusing as with Achro i may need to focus for all filters while with a lens or triplet i may not need to focus for each filters, but maybe 2 or 3, better than focusing for 5 or 7 filters, and hope i can buy autofocus motor one day but i have to make sure my lens is giving me results i need.
I am still learning, but i like to have right or nice setup before rather than depending in very simple and cheap gear even if they will do a job, so that i bought an astro cooling camera and filters, so i have to skip ST80 then and use something better, someone showed me an image from a triplet scope with exposure less than what i did with my ST80 and it was no comparison, only Ha, the image from that triplet was way way amazing with better stars or more stars and better contrast, so maybe that triplet even for one filter can resolve better results than an achro, at the end many are going this way with imaging scope, hope i can test my lens first and then i can decide which another scope, but i feel i will wait much longer and save budget so i can buy a Tak and never look back.