Hello All,
Right. Near enough at the 'Last Chance Saloon'! Going global !
I got the the Tak. collimating eyepiece and crosshair tube set from OPT yesterday to try and finally collimate a new'ish ( under a year ) 2.8 ED180 that I bought 'used' a couple of months ago. It had a pedigree of taking several published pictures and I picked it up without having a peek through it and when, after arriving home that evening, I had a looksee, it was woeful. The stars were smeared right across the field. In fact unrecognizable as such. The seller naturally enough pleaded total innocence. No matter, I had all the right tools: crosshair sight tube, Cheshire, a couple of lasers ( one, a LaserMax ) and a modicum of common sense. I thought.
Every tool ended up contradicting each other of course. Outside, on the one mag.4 night that's happened since I got it I couldn't get it together at all. The upshot being that at the end of December I ordered the Tak. collimating kit from OPT. Yesterday: joy ! No slop or play at all. Although the instructions are in Japanese of course, the drawings follow the time honoured sequence of events to line everything up. And yet, how is it that when I put the corrector back in the focuser and look across the valley here to some leafless trees on the skyline, I get to see more or less what I saw before ? Aside from a bit of kidney beaning, one side of the image will be sharp'ish and the other hazy.( Using a succesion of Naglers and Pentax's. 1.25" ) And so on. I would suggest it still isn't close to being anywhere near lined up. Stars,(given the opportunity!) I feel sure will still display as streaks. I'm given to wonder why?
Here's a pic. I snapped an hour ago which approximates pretty closely what I'm seeing in the collimating routine : sky end to the right of picture, and crosshairs rotated to line up over the spider.
The question is: does anything jump out at you as an obvious malady?
Cheers,
Bruce
Right. Near enough at the 'Last Chance Saloon'! Going global !
I got the the Tak. collimating eyepiece and crosshair tube set from OPT yesterday to try and finally collimate a new'ish ( under a year ) 2.8 ED180 that I bought 'used' a couple of months ago. It had a pedigree of taking several published pictures and I picked it up without having a peek through it and when, after arriving home that evening, I had a looksee, it was woeful. The stars were smeared right across the field. In fact unrecognizable as such. The seller naturally enough pleaded total innocence. No matter, I had all the right tools: crosshair sight tube, Cheshire, a couple of lasers ( one, a LaserMax ) and a modicum of common sense. I thought.
Every tool ended up contradicting each other of course. Outside, on the one mag.4 night that's happened since I got it I couldn't get it together at all. The upshot being that at the end of December I ordered the Tak. collimating kit from OPT. Yesterday: joy ! No slop or play at all. Although the instructions are in Japanese of course, the drawings follow the time honoured sequence of events to line everything up. And yet, how is it that when I put the corrector back in the focuser and look across the valley here to some leafless trees on the skyline, I get to see more or less what I saw before ? Aside from a bit of kidney beaning, one side of the image will be sharp'ish and the other hazy.( Using a succesion of Naglers and Pentax's. 1.25" ) And so on. I would suggest it still isn't close to being anywhere near lined up. Stars,(given the opportunity!) I feel sure will still display as streaks. I'm given to wonder why?
Here's a pic. I snapped an hour ago which approximates pretty closely what I'm seeing in the collimating routine : sky end to the right of picture, and crosshairs rotated to line up over the spider.
The question is: does anything jump out at you as an obvious malady?
Cheers,
Bruce
Attached Image: