Figured out a rig; works with any camera…

[ravnostic]

So I’ve been fiddling with ideas for piggybacking either a telephoto lens or (more recently revisited) a ‘spotter scope’ (it’s a Maksutov-Cassegrain Celestron C90; 1000mm [albeit f/11]).

I got my method. I only had to sacrifice a $30 tripod and buy a few bucks in random parts. Will be testing it tomorrow. I should have thought of it ages ago. If it works well, I’ll take it in to a machine shop and have them build something a bit more robust for long-term use.

For those who don’t know, an MC scope is useful as it helps with color and limits ‘coma’, which (as the name might imply), is the tendency for the stars’ light in the outer field to kind of spread outward, kind of like a comet’s coma.

My Schmidt-Cassegrain corrects for it with a corrector plate, but the Maks may be better. The downside is longer exposure times, so it may not work for deep nebulas and galaxies, but should be quite sharp for planetary viewing.

I’ll post picks when it’s finished; I bought a new Tamron 75-300mm f/4-5.6 that is VERY sharp; I may be using it with this rig as well; I could theoretically get even the entire Orion Nebula/Running Man/Horsehead Nebula with a wider lens. We shall see tomorrow; I’ll be going out.

Say Orionid; how’s your scope project coming along?

[ravnostic]

From the ‘Pics or it didn’t happen’ Dept.:

[fluffybunny]

Nicely done. I am dealing with similar issues but I want the smaller scope for electronic tracking correction. I have to rewire my hand controller, come up with a mounting system (your post above) and then hook it all up. I’m fixin’ to go into an ‘outrage’ (so coined by my little Niece, also know as outage) which means straight night shifts, ergo I hope to have some time for astrophoto work. Then again 6 x 12 hour night shifts each week can just suck the life out of you. We’ll see. I am an optimist. I think.

[ravnostic]

I’ve done the 6×12; it does duck out life. However, the pay is good, when you can get it, and worth it for short bursts at a time.

[chupathingie]

Cute little Mak! And yeah, even though the f-ratio is long on them the bang-for-the-buck is hard to pass on… spherical elements are cheap to make and Maks are very good at keeping tight stars across the field. If you’ve got passable guiding, you can make up for long FL with integration time. Good FOV for things like galaxies and most globulars, and many of the smaller nebulae out there. Yer gonna need a good Barlow for planetary stuff, or use a camera body with a small chip… a modded webcam would really shine for planetary stuff with a small Mak. Tiny chip, and at ~1 meter FL Jupiter/Saturn/Mars/etc would fill the sensor nicely…

[orionid]

Say Orionid; how’s your scope project coming along?

Currently stalled. See also 6×12 nights and, umm…. some other external stressors. I’ll put a little more detail in another topic in just a few minutes.

Nice setup, I’d been thinking along the same lines for piggybacking telephoto lenses. Did you ever get your permanent solution machined? Or have any samples from the piggyback?

[ravnostic]

Due to imperfections brought on by nasty light pollution, I won’t be using this in the astrofarktography contest, so sure, orionid:

https://plus.google.com/107857888121727893520/posts/bxePoV8WWu5?hl=en

A composite of 10-14 (I fergit) shots, one minute in duration each, detailing the center of the Milky Way. f/1.4. I’d do better with 2 minutes at f/2.8, I think, though.

[orionid]

Sweet mother of god.jpg

[ravnostic]

Actually, it’s just not that good. One shot is blurry (not sure why) and there are color seams from the different levels of light pollution where the stitching didn’t do so well with the color. But…I have another view, without the light pollution. You may be seeing that one here in a couple weeks (or not; haven’t done my final pickin’s yet.) But thanks regardless! It definitely shows some serious detail with the galactic core goodness!

[chupathingie]

Wow, still very nice… I need to find some time to get out and do some more astro shots but I have too much crap on my plate as it is. I’m just gonna have to lose sleep I guess.

[Author]

Posts