4.5", 6", and 10" Newtonian astrographs.
2 ST80s; ED80; 3 CCD cameras; 5 EQ mounts: all polished, tuned, and modified.
The rule of telescope features: aperture; equatorial tracking; or low cost. Pick any two.
Orion XT8 Classic, Self built EQ platform
AstroTech 72ED, AstroTech 6 Imaging Newt
Celestron Advanced VX EQ Mount
Celestron NexStar SE 4/5 Mount (for grab and go)
Canon T3i, Canon XT (Hap Griffin Baader Mod)
QHY5L-II Mono/Orion 50MM Mini
Fort Bend Astronomy Club
Quote:Thank you... That makes me feel better. The thing I don't understand is why some people swear that you have to get a Howie Glatter or Catseye collimator. Those suckers cost a lot of money, if you can even figure out what you need. To hear somebody say they ABSOLUTELY LOVE something that's cheaper, makes me very happy! LOLToo many expensive hobbies. I think that's what the problem is.
Quote:Thank you for your reply! That actually helped me a LOT! At this point, I'm leaning towards getting a TuBlug, and a 650nm laser collimator from Astronomics. I sent Astronomics an email and they told me that the TuBlug comes with a barlow built into it. (That was news to me, but good news. It means I wouldn't have to "stack" the barlow I already have below the TuBlug.)https://www.astronomics.com/glatter-1-25-inch-tublug_p18895.aspxhttps://www.astronomics.com/glatter-1-25-inch-single-beam-650nm-laser-collima...
Quote:So, does the bottom of the laser, with the barlow attachment, extend down into the OTA (far enough) so that you can see where the laser light (or shadow of the primary's center mark) is being cast?
Quote:I suppose I could get the 1.25"/2" laser with a Self-Barlow attachment, and if it turns out that I can't see the face of the laser... I could make a target the way Pharquart (Brian) did. I suspect I'd be able to see the face on the 2" focuser, but I have my doubts on the 1.25" one.The advantage of going this route would be that I wouldn't have to get a compression adapter, but I'm probably going to have to get one of those anyway, for my 1.25" eyepieces. I'll continue thinking about it, but I have a much better understanding of what each item does now. I'll probably make a decision on what to buy, in about a week.
Quote:My first post - I tried the -Orion LaserMate Deluxe II Telescope Laser Collimator yesterday for the first time, my 12" XT12i mirror was 1-1/2" off center from the secondary, still have to test the results on a dark sky.I recommend a laser for everyone with a Dobsonian. They go for about 50$
Quote:A small clip-on dental mirror attached to the spider would allow you to see up inside the focuser if you can't see the bottom of the laser with the self-barlow attachment.
Who you jivin' with that Cosmic Debris? "all science is either physics or stamp collecting" -- Lord Rutherford
Quote:At this point I'm (strongly) leaning towards Starman1's suggestion of a 1.25"/2" collimator with a barlow attachment. The TuBlug would be nice, but I think it's a luxury that I can live without, and I like the idea of being able to insert the 2" collimator directly into my 2" focuser, without any adapter.Starman1, I noticed that you don't have them in stock. Do you have any idea when they'll be available?
Quote:how do you test the collimation of the laser?I was going to see if my moon photos would come out nice and sharp as my test.this is what I had before the laser.http://www.flickr.com/photos/92681330@N06/8608814884/in/photostream
Quote:I suspect if you try to collimate your laser you'll do more harm than good. If it doesn't pass have the manufacturer fix it. FWIW, I tried a check on my laser collimator by setting it on the edges of a solid but slightly open vice. I observed the laser rotated in a circle about 1/4" diameter on a wall 30' from the laser. Nils Olof Carlin said that degree of error was acceptable.
Present gear: 16-inch f/4.5 Dobsonian 50mm straight through-finder Green laser pointer 26mm, 32mm, and 38mm 70 degree field EPs 4.7mm, 14mm and 18mm 82 degree field EPs 8mm, 17mm, 21mm 68 degree field EPs 2X 2" Barlow Tirion star atlas (white stars, black background) hand-laminated Megastar Editor & co-founder Las Vegas Astronomical Society Observer's Challenge To nudge or not to nudge, that is the question www.fredrayworth.com
Quote:I've been reading up on autocollimators. This is more than just a collimation cap. It has a mirror on the inside surface, which results in several iterations of the reflection ping-ponging back and forth between the primary, secondary, and autocollimator mirrors. So when you look through the peep hole, you actually see four different reflections of the center spot. The off-set peep hole is for this reason (I think): Apparently just before you get to total collimation of the primary with an autocollimator, the multiple reflections of the primary disappear and it looks collimated. But the secondary still can be off and you wouldn't see it. The off-set pupil lets you look "behind" the reflection to see whether there remain secondary mis-alignments. If I understand all this, there is a similar procedure to the off-set pupil avaialble with the laser collimator called "Carefully decollimated primary" (CDP), discovered by Vic Menard, whereby you purposefully de-collimate the primary using one screw, moving your laser reflection off to the side of the barlowed return disk (sort of like looking through the off-center AC pupil). This in turn allows you to see mis-alignments in the secondary that need to be made. Then you put the primary mirror back where it was.I'm not sure if these two procedures (off-set AC pupil versus CDP) are really analagous, but they seem similar to me. I question whether the AC would provide any further palpable advantage beyond the barlowed laser.
Jim Fly - Manufacturer
Quote: The "CDP" pprocedure is done using the central pupil of the autocollimator - not a laser. See procedure here: Vic Menard's CDP Protocol
Quote:Q: I question whether the AC would provide any further palpable advantage beyond the barlowed laser. A: Well, that depends on how fast your scope is and whether you use a coma corrector. The use of a coma corrector requires much tighter tolerances.
SyedTeeter STS 11 f/4.3 Zambuto | XT8i | XT8g | XLT 150 | C90 | EON 80mmAT Voyager and Nexstar SLT mountsEyepieces: Mostly TeleVue and PentaxDenk II BV'er, Earthwin PFS-SE, Pentax 10x50 PCF WP II
Quote:Quote:Q: I question whether the AC would provide any further palpable advantage beyond the barlowed laser. A: Well, that depends on how fast your scope is and whether you use a coma corrector. The use of a coma corrector requires much tighter tolerances.I have a Z10 (F5) with stock focuser. Between a coma corrector, an autocollimator, or upgraded focuser, which do you think would make the most improvement for a "next step?"Pete