Altair 10" RC

[r3i]

I'm also pleased with the RC, my enduring problem is the chip in my QHY8 is tilted which has added an additional variable into the mix. I have the TS focus collimator which in the past I had difficulties in getting a consistent result with in the limited time I had available to get set up, but now I'm observatory based I am hoping I can make a better job of things.

As an alternative I've got one of these incoming - http://www.gerdneuma...lting-unit.html. This device is supposed to be easier to adjust but also it should allow me to square up the chip when I want to take wide field shots through my refractor, the TS collimator being dedicated just to the RC. And, being a gadget junkie, it's another new toy to play with .

I'm not knocking the Cheshire at all, my gut feel is that it can do a good job on the RC but it would be interesting to compare and contrast with other collimation tools and methods.

Will look forward to seeing your vids of the Glatter on YouTube.

[kirkster501]

Been looking more into this and playing with the laser. I thought I could get away without the tilt plate that Jeffrey Jongmans uses but I think this is needed to keep all three planes of collimation independent from each other. I also find that the focuser must be left in the collimated position and NOT removed needlessly or else you risk upsetting the collimation. I think I need to buy the tilt plate now.

Steve

[r3i]

Been looking more into this and playing with the laser. I thought I could get away without the tilt plate that Jeffrey Jongmans uses but I think this is needed to keep all three planes of collimation independent from each other. I also find that the focuser must be left in the collimated position and NOT removed needlessly or else you risk upsetting the collimation. I think I need to buy the tilt plate now.

Steve

Steve, one thing worth checking is how tight you have the silver lock bolts on the primary cell. I noticed that unless you had them pretty tight there was a potential for flexure there.

[kirkster501]

Thanks for the tip, yes will check into that. A couple of my images through my RC8 here.

Either the collimation is not spot on (I am 99% sure this is the case) or my guiding is slightly out at this FL. My collimation is not miles out but it is off a bit.

I am going to buy the RC8 tilt plate and will update here what I do and make some videos after I get that - no point doing anything to the scope until I get that plate. Already done a video of the Howie Glatter that I will upload when i get time.

[jjongmans]

You'll definitely need the collimation ring.

[kirkster501]

You'll definitely need the collimation ring.

Yes indeed, I have come to that conclusion as well. Without it cannot get independent adjustment of the three planes of collimation.

As I said about though, I find that turning the focuser also fractionally moves the laser on the centre spot. That implies to me that once the collimation is done and set do NOT take off the focuser!

Also Jeffrey, your method assumes that the centre spot on the secondary is 100% correct right? It might not be.....

[jjongmans]

As I said about though, I find that turning the focuser also fractionally moves the laser on the centre spot. That implies to me that once the collimation is done and set do NOT take off the focuser!

Also Jeffrey, your method assumes that the centre spot on the secondary is 100% correct right? It might not be.....

When everything is collimated, don't touch the focuser again.

The centermark is almost certainly not aligned with the optical center, but it's the best you got. That's why you need to do a startest to get everything perfectly aligned.

[kirkster501]

When everything is collimated, don't touch the focuser again.

The centermark is almost certainly not aligned with the optical center, but it's the best you got. That's why you need to do a startest to get everything perfectly aligned.

... and the startest is to adjust the primary or the secondary? Reading your previous posts I think its the primary..... ? But that then changes the focuser and secondary alignment requiring another iteration, that would necessarily need to be done in the dark to take advantage of the ability to do a star test?