I found that relying on laser Collimator only doesn't assure to align the secondary Mirror with the focuser.. You need a a collimation eyepiece to adjust the secondary mirror first which is cheap. Thanks for the video
just joined up and the wealth of knowledge is invaluable! Thanks for all the work behind the videos and website maintenance! I know how much it can be at times!
very nice filming and presentation, the laser colli is...ok, at best...you really need to look into the cheshire combo tube....after that your collimation will be spot on...trust me (as a 10" SW250P user)..I also invested in the Howie Glatter Parallizer for Newts...a great tool
Thanks for the upload. Great explanation and filming. Makes the thought of collimation a little less daunting..... I haven't actually collimated a telescope before (I have a 5" Newtonian) so I am no expert although I have tyried to educate myself by reading and watching rticles such as yours. One thought that bothers me a little is that the effect of a collimation tool not being in collimation itself. There are all sorts of articles out there showing some laser collimators not being in true and subsequently throwing out the true collimation of the mirrors. Such is life, but it is something I think that should be considererd. Thanks again for all your uplaods, they are all very informative & helpful.
Laser collimaters lie. Theyre useless unless they themselves are collimatable. In other words, the laser should have collimation screws just like the secondary mirror and should be checked before use. Also, even if the laser is properly collimated its possible to center the spot on the primary mirror with the laser by introducing errors into the tilt and tip of the secondary. In other words, single spot lasers lie. A Cheshire eyepiece with cross hairs and a collimation cap is the first thing you should use, along with two different colors of paper to cover the primary mirror and to put opposite the focuser. This eliminates the reflection of the primary through the eyepiece so you can center the secondary under the focuser first. Check out Astronomy Shed for proper collimation procedures.
one trick...put a little semi transparent sticky tape over that 'big hole' in the laser collimater so you can see when the returning laser dot acrually hits the center of the hole
Not all reflectors have a center doughnut. I have a four inch Zhumell100 where you cannot adjust the primary mirror at all, only the secondary mirror is adjustable. It is a pain in the rear to adjust it and you better know it came out of adjustment. Notice he did not check the laser tool to see if it was out of adjustment itself. You put the tool in a V block with the light turned on and aim it at a small mark you make on the wall about 6 feet away. Spin the tool in the V block and watch and see if the light wobbles around or if it stays in one spot as you spin it. I bought the exact same one as he's got because it was the cheapest battery. There was another laser collimator that was cheaper, but the battery was crazy expensive. There are videos showing you how to put a center spot on your primary mirror, I won't go into it as my Starrett Square came with a center finder, easy-peasy. Remember it doesn't matter if you mess up the center of your primary's center a little because the secondary mirror covers up at least a one inch diameter of your primary's center. As for using a Cheshire tool that's fine if you know what you're doing, but not much help if you don't. I double check my collimation with Polaris the North Star. This really only works if you have hand controls to center Polaris precisely and then take it out of focus slightly and see if the star rays are even from the secondary mirror's spider. If they are you got it.
Hello ive done exactly what youve done all lined up spot on but i can see jck shit through my telescope only the primary and secondary cant see anything moon stars anything any ideas ?????
8:00 what if I can't see the dot the target map to start with? I've tried hours to get it into place with no success, probably messing up the angle even more now.
@@lovethenightsky5778 I took my entire scope apart. Removed the primary mirror completely out of the OTA. Same with the secondary mirror. Keep track of the springs, washers, knobs, etc. Make sure you know how many you have and where they go. In my case three springs, one with each adjusting knob at the back of the OTA, by the primary mirror. Another (identical in my case) spring behind the secondary mirror. So three springs at primary, one at secondary. Once out of the scope I cleaned all glass with eye glass cleaner and a good eye glasses cloth. Wipe clean. Reassemble. My telescope is a ten inch dobsonian from Zhumell (GSO). I do not know if this is a good approach but it worked for me. Took some time. Maybe a once or twice a year job. Maybe there is an easier way. I may do a video next time I do it.
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