Over the last two months, I've come close to what I am capable of as far as improving my existing scope and mount. It was a terribly inexpensive 8" Newtonian. The mount was a German equatorial mount, essentially a copy of the Celestron EQ-4 (which in turn was a copy of the ever-present CS-5 of yore). The tripod was just a bit of comedy; no one could have meant it to be actually used...right now, it has all sorts of stuff bolted to it for bracing. I had to add additional bracing from the scope rail to the counterweight post to try and settle down the wobblies as well. Many of the worn or badly made parts I have either remade myself or found in a local store's junk pile; I have about $7 invested in replacement parts now! The scope itself seems to want daily collimation; I'm considering adding bracing to the tube itself since I suspect it's actually deflecting under the combined weight of the primary and a camera. It's VERY thin sheet metal rolled into a tube. My eyes are open for someone with a higher-quality 8" Newtonian who perhaps has broken their primary mirror...
The whole thing is very Rube Goldberg, but without spending a lot of money, it's as good as can be expected. As I mentioned in the very first post, there's no budget for this right now. Plus, I've gotten a mildy perverse pleasure from getting by without fancy hardware and computer Go-To systems. But trust me, if I had them, this old stuff would be in the trash heap ;)
The remaining improvements on the list are
*bracing the tube, as mentioned
*building a flats box, so flats can be shot at the same time the lights and other reference frames are collected
*finding a motor for the declination axis (it's hand-turned now)
*seeing if more play can be removed from the RA drive (as is now, 40 seconds out of each 3 minute window is ruined as the drive moves from one tooth the the next. That's 2-3 out of every 7 30-second shots. That's as good as I can get it.)
*obtaining enough heavy black fabric and a way to hang it to create a "dome" around my viewing area.
*Building a better tripod or stand. I may just need to sink a pole into some concrete, but I want to be able to take the scope to dark sites as well.
I feel like I've gotten the essentials of DeepSkyStacker down; there is no doubt a lot yet to learn there. As for the tube flex and reference shots-the "flat" shots are taken of scattered white light, and tell the software just what flaws my scope has (vignetting, dirt, etc.). Using flats in processing should even out the dark backgrounds, rather than leave a lighter circle in the center. (See this picture from below for an example-the galaxy just happened to be on the fringe of the light area.) My flat-frame correction has been failing to get the result I want; I now think it's because they are shot against the sky the next morning, with the scope out of the mount, resting on its tail. I want to shoot the flats at the same time the main pictures are taken to avoid any effects of the tube flexing; that is what a "flats box" is; simply a box with a white light and a diffuser in it. Collimating needs to be done with the scope mounted as well, and the weight of my camera in place somehow; if the extra weight is warping the tube, then my collimation problems are explained. (Collimation is the precise alignment of all the mirrors and lenses.)
I'm not sure if I'm going to get that set of 10 or 15 second subs of M42 I wanted; we have bad weather predicted, and time is running out for Orion in 2011...pity, since the bright objects are less affected by my local conditions.
The whole thing is very Rube Goldberg, but without spending a lot of money, it's as good as can be expected. As I mentioned in the very first post, there's no budget for this right now. Plus, I've gotten a mildy perverse pleasure from getting by without fancy hardware and computer Go-To systems. But trust me, if I had them, this old stuff would be in the trash heap ;)
The remaining improvements on the list are
*bracing the tube, as mentioned
*building a flats box, so flats can be shot at the same time the lights and other reference frames are collected
*finding a motor for the declination axis (it's hand-turned now)
*seeing if more play can be removed from the RA drive (as is now, 40 seconds out of each 3 minute window is ruined as the drive moves from one tooth the the next. That's 2-3 out of every 7 30-second shots. That's as good as I can get it.)
*obtaining enough heavy black fabric and a way to hang it to create a "dome" around my viewing area.
*Building a better tripod or stand. I may just need to sink a pole into some concrete, but I want to be able to take the scope to dark sites as well.
I feel like I've gotten the essentials of DeepSkyStacker down; there is no doubt a lot yet to learn there. As for the tube flex and reference shots-the "flat" shots are taken of scattered white light, and tell the software just what flaws my scope has (vignetting, dirt, etc.). Using flats in processing should even out the dark backgrounds, rather than leave a lighter circle in the center. (See this picture from below for an example-the galaxy just happened to be on the fringe of the light area.) My flat-frame correction has been failing to get the result I want; I now think it's because they are shot against the sky the next morning, with the scope out of the mount, resting on its tail. I want to shoot the flats at the same time the main pictures are taken to avoid any effects of the tube flexing; that is what a "flats box" is; simply a box with a white light and a diffuser in it. Collimating needs to be done with the scope mounted as well, and the weight of my camera in place somehow; if the extra weight is warping the tube, then my collimation problems are explained. (Collimation is the precise alignment of all the mirrors and lenses.)
I'm not sure if I'm going to get that set of 10 or 15 second subs of M42 I wanted; we have bad weather predicted, and time is running out for Orion in 2011...pity, since the bright objects are less affected by my local conditions.
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