Peter Berry

9 hours ago, Roberto Tolin Sommer said:

Another attempt with the GH3 and the 1.000mm catadripotic tele. Jupiter and four moons, Europa, Io, Ganimede and Callisto. 

 

A pretty fantastic shot from only 2000mm EFL, and takes excellent scope optics. ?The Russian Astro Rubinar 1000mm f/10?

16 minutes ago, Andrew Reid said:

In terms of ex-tele on the GH5, might as well you shoot in open gate anamorphic as that uses the full sensor resolution, then you can crop 1080p from that in post, rather than bake the framing in-camera with ex-tele.

Regarding the crop factors, I simplified things to only horizontal crop factor... if you take into account diagonal of 16:9 you might see slightly different numbers.

What is everybody using for their longest telephoto zooms or primes? Would be great to see a list of options to consider, outside of just the ones I am thinking about.

Canon 400mm F5.6L has AF and looks like nice 1.2kg alternative to the 5kg Canon FD 400mm F2.8L. Add that to the list.

Wow. Did you ever try this setup with a more modern camera? Imagine that telescope with a D850!!

Andrew, the problem with a much larger sensor than the tiny video chips of yore is that you have to use a significant zoom lens on the camera (or a long FL prime) to couple to the scope eyepiece/TC train. I've tried my GH4 w/ the compact Panny 14-140, but just too bulky, with a relatively small circular image shown, or no focus-able image all. My next iteration was the Sony HC1 FHD camcorder, but never found suitable astronomic "seeing" to warrant the time and effort of setup with the 9.25" f/10 scope.

What I have done with it is total solar eclipse recording of solar flares and detached prominences, but with a very compact and excellent 4" 1000mm f/10 reflex scope w/ tube length only 8" using an eyepiece coupled to the Sony lens, but no TC. First pic below with the VGA res. TRV-900 of the striking detached prominence - Africa '01; the second with the FHD Sony of the "hedgerow prominences" I've not seen imaged in this detail - Turkey '06. For the recent eclipse I viewed and imaged from Madras, Oregon, I used my GH5, Canon 100-400-II w/ 2X TC shooting 4K in ETC crop mode (2.7X crop factor), plus 2X dig zoom or this to 1080p res and 5.4X factor = 4320mm EFL. Tech. screwups on my part nixed any views of the pretty unimpressive flares at this mag.

5 hours ago, Andrew Reid said:

I know nothing about telescopes.

Any info, bring it on.

Here's a sort of uber-imaging setup with a 9.25" aperture/2350mm f/10 Schmidt-Cassegraine compound scope with an afocal imaging setup about 15 years ago: Sony TRV-900 3-CCD VHF camcorder with full man. controls, SS down to 1/2 sec connected to a telescope eyepiece (this is the "afocal" setup) which is connected to a 3X TC (Barlow lens in astro lingo). The Jupiter images filled about 2/3 frame height with the Sony at about 10X zoom. This method makes finding the object pretty easy zoomed out, works well in spite of the huge # of optical elements involved, and zoomed-in gives enormous mag. - maybe ~ 20-25 meters EFL @ f/100?

The film clips were processed in Registax, which selected the sharpest (due to brief reductions in atmospheric turbulence), stacked 400-600, which accentuated common detail features, than a complex multistage "wavelet" sharpening routine. The first Jupiter image was from the steadiest "seeing" conditions I've ever had - in the Florida Panhandle. The Mars image at it's historic closest approach in 9/3/03, from southern Mexico.