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There's astrophotography and then there's astrophotography, however - and you get drawn deeper and deeper into it. I have a few scopes, but mostly use an 8" ce

There's astrophotography and then there's astrophotography, however - and you get drawn deeper and deeper into it. I have a few scopes, but mostly use an 8" celestron schmidt-cassegrain - it's a decent all-rounder for astrophotography, particularly as I mostly do deep sky stuff. I started with a simple T-adapter and a DSLR, and of course, you start as you describe playing with the exposure, the iso - but then you want to see fainter objects, and the noise starts being a problem, so you learn about computational techniques for frame stacking and noise reduction, but those have their limits, and the results you're getting are so-so, so... You buy a peltier cooled CCD. You upgrade your mount because you aren't satisfied with the level of backlash you're getting. You get a star tracker. You learn several suites of astrophotographic software before settling on three. Now you're taking images of deep sky objects, but they just don't have that certain something - so you go and buy filters - hydrogen alpha, OIII, RGB, and more, and you start getting some images you're impressed by - but... wouldn't it be great if you could just capture a bit more of that dim halo... maybe I should buy a bigger telescope. Maybe I need a dome to keep conditions more constant. Perhaps I should go on holiday and lug my telescope, counterweights and all, to the other side of the planet, and hang out up a mountain. No, this is madness. So long as you stick with what you describe and don't go down the slippery slope as I did. With the setup you describe you can still do neat stuff like observing the Galilean moons and plotting their ephemerides, and take stunning photos of the moon and even the sun with a simple solar filter.

vvanders 10y ago
Yup, no idea what GP is talking about, most dobs aren't really great for AP since the focal plane isn't in the right location. I'm a huge photo-nerd but I took one look at AP and was like "nope!" for the exact above reasons + extremely long capture times. We're talking hours of frames to see some things.
- aortega 10y ago
  It's mostly automated.
- deleted 10y ago
  [deleted]
dr_zoidberg 10y ago
About capturing a bit more fo that dim halo, I always wondered... Wouldn't a secondary scope (with similar characteristics) result in an increased light gathering potential? I've also tried to look into visible-light interferometry, but there aren't many accessible resources on the subject. My feeling is that there is a point in equipment in which you are simply better off getting a new rig (to work in paralell) than trying to get slightly bigger aperture (let's face it, 16" vs 14" is not as dramatic in light gathering and image quality as 8" vs 6"), but I'm not sure where that point lies.
- aortega 10y ago
  But you also need another camera and probably another mount too. The scope is actually the cheapest component in a astrophotography setup. Probably the 80% of the cost is the mount+the camera.
  - dr_zoidberg 10y ago
    Absolutely. Then again, there are limits. I remember an old Meade model (no longer available) that was a 20", $36k monster. I was beautiful, and they sold it as an observatory-grade instrument. But the 16" models were priced close to $10k, so it sort of made sense (in that particular case) to duplicate the rig. My "napkin analysis" was: 20" diameter, ~315 squared inches of area[0], $36k 2x 16 inches diameter, ~402 squared inches of area, $20k This prices did include mounts, but back then (more than 10 years ago) I wasn't very knowledgeable and I honestly don't know if they were good mounts. So there was margin to increase the light gathering and having spare money for the new camera. Still, the most interesting use for multiple telescopes would be building and interferometer. I'll keep looking into that, with the procesing power available in todays machines it should be doable. [0] I know the secondary mirror obstructs the light gathering, but I don't have precise figures, so let's go with it the area of the main mirror.
- deleted 10y ago
  [deleted]
aortega 10y ago
I just went straight to the cooled CCD/C11/hyperstar and don't repent. I would like a better mount though, but my EQ6 is just fine. Now I actually need a smaller scope :)

vvanders 10y ago

Yup, no idea what GP is talking about, most dobs aren't really great for AP since the focal plane isn't in the right location. I'm a huge photo-nerd but I took one look at AP and was like "nope!" for the exact above reasons + extremely long capture times. We're talking hours of frames to see some things.

aortega 10y ago
It's mostly automated.
deleted 10y ago
[deleted]

dr_zoidberg 10y ago

About capturing a bit more fo that dim halo, I always wondered... Wouldn't a secondary scope (with similar characteristics) result in an increased light gathering potential? I've also tried to look into visible-light interferometry, but there aren't many accessible resources on the subject. My feeling is that there is a point in equipment in which you are simply better off getting a new rig (to work in paralell) than trying to get slightly bigger aperture (let's face it, 16" vs 14" is not as dramatic in light gathering and image quality as 8" vs 6"), but I'm not sure where that point lies.

aortega 10y ago
But you also need another camera and probably another mount too. The scope is actually the cheapest component in a astrophotography setup. Probably the 80% of the cost is the mount+the camera.
- dr_zoidberg 10y ago
  Absolutely. Then again, there are limits. I remember an old Meade model (no longer available) that was a 20", $36k monster. I was beautiful, and they sold it as an observatory-grade instrument. But the 16" models were priced close to $10k, so it sort of made sense (in that particular case) to duplicate the rig. My "napkin analysis" was: 20" diameter, ~315 squared inches of area[0], $36k 2x 16 inches diameter, ~402 squared inches of area, $20k This prices did include mounts, but back then (more than 10 years ago) I wasn't very knowledgeable and I honestly don't know if they were good mounts. So there was margin to increase the light gathering and having spare money for the new camera. Still, the most interesting use for multiple telescopes would be building and interferometer. I'll keep looking into that, with the procesing power available in todays machines it should be doable. [0] I know the secondary mirror obstructs the light gathering, but I don't have precise figures, so let's go with it the area of the main mirror.
deleted 10y ago
[deleted]

aortega 10y ago

I just went straight to the cooled CCD/C11/hyperstar and don't repent. I would like a better mount though, but my EQ6 is just fine. Now I actually need a smaller scope :)