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Howie Glatter collimator

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#1 jmoore

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Posted 19 January 2004 - 01:41 PM

I just got my Howie Glatter laser collimator in the mail last week. :jump:

Mechanically, it is awesome. First, it's diameter fits PRECISELY in my focuser. Absolutely no play whatsoever. So, I wasn't left wondering whether I REALLY wanted to shift the laser spot on my primary to my primary's center spot. Secondly, the laser itself is perfectly collimated. When rotating the laser around its axis, the laser spot on my wall/primary mirror/collimator face, etc. does not change position at all.

These were really good signs, and gave me faith that I could collimate with confidence. So, I did....

There is a little slop in my scope's focuser itself (and/or my focuser isn't perfectly squared, or something), so when I racked my focuser between its extremes, I found that my collimation (both primary and secondary) needed to be adjusted slightly. So, I made sure to collimate with the focuser sort of in the middle. This helped ensure a few things: 1) that collimation is good where my focuser is likely to be most of the time, 2) that collimation error is minimized if/when I need to rack the focuser all the way in or out, and 3) that the overall precision of the laser collimation is increased (which is theoretically not as precise as Cheshire collimation) because I'm adjusting my scope to the average collimation.

So, after collimating, I braved the 10-deg Indiana night, and took my scope out for a couple hours. By the way, I have an 8" f/5 Newtonian. Whatta ya know? My collimation was RIGHT ON. My star-test looked much better than I've been able to get it recently without the laser (granted, I'm still in the process of gettin' this whole collimation thing down). The atmosphere was turbulent, so I couldn't see clear stable concentric diffraction rings, but as far as I could tell, all appeared very symmetrical...much moreso than on recent star-tests.

Further confirmation of collimation success was the beautiful views I got of Saturn...MUCH better than any recent Saturn views through the same scope. Last night, I saw really crisp detail in the rings and on the globe...Cassini division was clear all the way around...and I caught several glimpses of the C-ring. I could only go about 275x (my next power was 333x, which looked a bit fuzzy), but then again, seeing was not so great last night...only about 5/10 I think. Compare this to my recent, uncollimated views of Saturn, which were fuzzy and featureless at anything above 100x.

Incidentally, this satisfying experience was achieved in spite of the fact that I think my focuser needs some squaring/aligning. I am unable to center my secondary under my focuser, so when I've got everything optically collimated, my collimation circle (from Chesire) is not centered in either direction on my secondary. I think my secondary may be rotated slightly (to compensate for the unsquare focuser).

So, I'm pretty darn pleased. I would not hesitate to recommend the Glatter collimator to anyone. :bow:

cheers,
Jeff


#2 Guest_**DONOTDELETE**_*

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Posted 05 February 2004 - 05:06 PM

Jeff
I also recently purchased a Howie Glatter collimator and
am pleased with the results. I also got the barlow laser attachment Howie is now selling as an insert to the laser unit. Works perfect. I have an f4.5 scope and had been having trouble getting it right.
Mike

#3 jmoore

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Posted 05 February 2004 - 05:58 PM

So you can get them with a Glatter Barlow attachment now? That's good.

I tried the Barlow technique by using a regular 2x Barlow that I already owned, but the Barlow wasn't machined as precisely as the laser-collimator was. Thus there was slop between the Barlow and my focuser, which affected my results. This is the very problem I was trying to get away from by buying the Glatter in the first place, so I just collimated without the Barlow. I think I'm getting really great results with it.

You know, I wonder if the Barlow is really helpful. Yes, you get more precise collimation, but this would only help you if it actually stayed that way. Since my collimation changes slightly depending on the weight of my eyepiece, the location of my focuser, and other environmental factors, it doesn't seem there's much point in trying to get it super duper precise. It won't stay there anyway.

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