Ad Astra Observatory

The MPCC is up there with the ST-4 as one of my Best. Astronomy. Purchases. Ever. My 8” f/5 Newt was almost worthless for DSLR photography before I added the MPCC. Now, it’s really quite good. It’s no Epsilon, but on the other hand, it cost about an order of magnitude less, too.

I have used it with the Newt, a C-8 SCT, and with an AT66 refractor. It helps out with the SCT, too, but the refractor didn’t actually have any coma to begin with, so the MPCC created “reverse” coma (comets flaring towards the center!), so I run the camera “naked” on the ‘66 now. It still has some field curvature, but I’m going to have to fix that some other way. I have considered a f/6.3 reducer/flattener, but I really

don’t need the extra FOV when I’m starting at 400mm; as it is, there are only about a half-dozen targets that are well-suited to the ‘66 (Veil, N. America, M31, Rosette, Pleiades, IC1396), and making the FOV larger wouldn’t really bring anything else in (unless I wanted a real deep picture of the whole constellation of Lyra or something (: ), so I seek a flattener that’s not a coma corrector and also not a focal reducer…
sigh. The pain I must go through for my Art. 😀

Also on my “wow, what a difference” list is the IDAS LPS filter.

I have this crazy idea of defeating my suburban light pollution and full moons by doing some narrowband imaging with the DSLR. So far, I haven’t found a filter system that meets all my requirements:

– uses 2” filters
– doesn’t require removing the camera and replacing it (I can never get the rotation right)
– costs less than $500
– doesn’t seem to require a “flat front” camera.

The closest I got was the filter drawer system from Astronomik, but I couldn’t get the thing to attach to my T-ring (it hit the flash housing). I could attempt to use a T-extender (which I couldn’t find at

the time), but then I wonder if the MPCC would get thrown off by being in the wrong position relative to the CCD…

Denkmeier has a similar thing, which takes either T or 2” on the camera side, so I could run MPCC into that “above the filter”, but then backfocus starts to become a problem…

I am starting to try to get into some of the smaller Messier galaxies (it doesn’t take long to get down below 10′), and I’m finding that it takes a *lot* of telescope for the big DSLR chip to really “do justice” to something even as small as M51. My light pollution is going to start killing me before I get *too* dim, but I picked up the C-8 to see if I could tease a little more out of the sky before I ran out of mount. If all goes well, the 13” will give me (I hope) another magnitude, which should get me down to 5′ or so.