Posts Made By: Tom Hole

Philip,

I am not experienced enough to help with your laser collimation problem. But I wanted to share with everyone a video that a right nice fellow put together on how to collimate with a collimation cap. It provides some most excellent gouge and even better animation on what things should look like. I apologize for not answering your specific question, but this site has some great tutorials for us new guys.

http://www.andysshotglass.com/Collimating.html

Clear skies,

Tom

Actually, I just went and viewed the video again and it has some laser gouge.

Philip,

That video didn't mention squaring the focuser and that is an excellent point brought up by other folks.

If you have a 4 vane XT10(i), I have found a quick and easy way to check your focuser for square:

http://www.tomhole.com/Focuser.htm

It's at the bottom of the page.

Clear skies,

Tom

Just to close the loop, here is my plan.

I asked Carl to ship the mirror to Spectrum for re-coating (he had to strip it for testing). Upon its return, I will humbly place a 1" black circle of some as yet unidentified composition over the blemish and move on. It seems to me that all I have done is added to my "central" obstruction by 1" diameter (.785 sq in). So instead of having a 1.83" secondary, I have a little larger one (about the equivalent to a 2.1" secondary). So I have a 19% obstruction instead of 16%. I can live with that.

I will replace the mirror someday.

Many thanks for the thoughts and advise.

Tom

Ron,

I've posted these before, but I think they are worth adding to the thread:



11" Starmaster, 305x. Represents what I saw (i.e. this is not my image).

Here are 3 more representations under different seeing conditions:

Good:



Avg (for me):



Bad (I get a lot of this):



I like the first image as a representation of what I saw, but the level of detail can vary based on the resolution of your monitor. I can say that your image looks like what I might see on a 5 of 10 seeing night. Not great, but fun to look at.

Clear skies,

Tom

Hmmm, how's about this:

32 mm plossl (TV is good) or 30 mm Ultima - Nice widefield ep ($120 ish)

18, 12, 9 mm UO orthos - These are the BEST bang for the buck anywhere in ep's. ($165 ish)

2x Barlow - TV, Ultima, Orion Shorty Plus ($70 ish)

That's run ya about $350 ish and you will never need another ep. Of course, you will want many more and probably buy many more, but you won't need anymore

Clear skies,

Tom

It's for an XT10 but the list is germaine:

http://www.tomhole.com/ORION%20XT10.htm

Tom

He has been assymilated 8O

Tom

Floyd,

Looks great. If you hear a couple of closely spaced, really loud booms, that's just a UFO. Looks like you're right under a supersonic cooridor in the military airspace right over your head. Shouldn't break anything, but you might need to recollimate that 15 incher.

Have fun,

Tom

I'm not a libel attorney, but I'm not sure the internet is a place of public record. At least not legally. Maybe it is. If so, I love everyone, unless it's illegal.

I have been following the ZOC/Starmaster/Torus/Obsession threads as a Starmaster owner. Obsession certainly blasts someone's optics on their website, questioning their testing methods, published mirror data, mirror mounting methods and other such silliness. I call it silliness as they spend as much text denegrading the competition as they do espousing their own product. I'm not a big fan of that method. Wonder who they're talking about? Synta? Meade? Guen Sheng? Nah, he's talking about Carl Zambuto, and not very nicely, I must say. Up until this exchange in public, I had thought of Obsession as a pillar in the big dob pantheon. They didn't seem to have a product that required derogatory advertising to sell.

Carl rebutted on his Yahoo group stating that he thought the claims lacked merit and felt they were a personal attack on him and his business. His thoughts are not on the Starmaster website and he doesn't seem to care to make it so. Someone called his mirrors/methods/numbers into question and he's pissed about it.

I'll continue to watch and see where this goes. There is a side-by-side comparison brewing, sort of a clash of the Titans, that would be most excellent to participate in and interesting to read about. Not sure what it will prove, but I'd love to go back and forth between a big Starmaster and a big Obsession, over and over again, trying to see which was better. Put duct tape over the name plates and run a double blind test. At the end of the night, I'm sure the purpose of the test will be lost in the wonder of the views.

Tom

Howard,

I live in MD and I'd rate my average seeing as 3 on the Pickering scale. Occasional (20 nights/year) jaunts up to 5-6, and rare (3-4 nights/year) excursions to the promise land of 7-8 Pickering. I have on one wonderful occasion had perfect seeing with which to view Jupiter.

On my average nights, 200x is the limit on planets in my 11" Starmaster. Anything more just makes the turbulence more noticable. On the occasional nights, Saturn can handle magnification in the 300x range and Jupiter is a treat at 250x. On those rare nights, Saturn is upped to 400x and Jupiter looks great at 305x. On the perfect night Jupiter looked best at 350x. Any higher just seemed to wash out the contrast.

So, that is one reference. 177x is a good place to start eeking out detail on planets. Anything lower and the image scale is just too small to see fine details, even in perfect seeing. For your 6" scope, you should be able to handle 300x on good nights (50x / inch) and maybe even more on great nights. Depends on the figure of your optics.

So, that's my take. Others will add their experience as well.

Clear skies,

Tom