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Micrometer eyepiece

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#1 Rolex2

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Posted 01 November 2013 - 09:50 AM

Is it true these eyepieces are no longer available? What eyepieces are used for double star separation? Rowland

#2 Michael Rapp

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Posted 01 November 2013 - 10:18 AM

Hi Rowland,

I'm a beginning double star observer and I also asked this question. What I found is that micrometers are rare and Van Skye Engineering has ceased production of them (alas, ceased to exist as well).

I stumbled upon some articles in S&T that use the Celestron Microguide Eyepiece and Meade Reticle Eyepieces for DS measurements. (The Celestron eyepiece is out of production, but I believe the Meade one is still available.)

See Observing Double Stars for Fun and Science, S&T Feb 1999 (Also partially available here: http://www.skyandtel...341.html?pag...

and Double-Star Measurement Made Easy, S&T July 2000.

It does look like fun....but I'm still honing my star-hopping skills before I start seeking out doubles for measurement. While simple, it is not a quick process. One must repeat one's measurements many, many times over several nights to minimize error.

I've been enjoying adding double stars to my observing. It is refreshing to stare at the center of the field of view for once. :D

#3 R Botero

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Posted 01 November 2013 - 11:57 AM

Hi Rowland

The Japanese maker of the micro-guide eyepieces ceased production (altogether) after the earthquake/tsunami of 2011. Despite this, some vendors still have some in stock (Teleskop Service ) and these eyepieces do come up in the secondary market from time to time. I acquired mine that way and they are an excellent tool for beginners into double observing like myself.

Michael has already cited some very interesting articles. I also thoroughly recommend reading Bob Argyle's Observing and Measuring Double Stars by Springer. There is a whole chapter on using the micro-guide eyepiece.

Good luck and enjoy!

Roberto

#4 Ed Wiley

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Posted 01 November 2013 - 03:50 PM

If you are interested in measuring for publication, I might suggest video capture or ccd capture as alternative to either micrometers (expensive if found) or eyepieces. But if you are doing this only for your own pleasure, then a Meade or Celestron eyepiece is great and, in fact, can be used for measures that can be published. I don't know how hard it is to find one, but I bet you could turn one up in the used market.

My suggestion to anyone interested in measuring is to look through the JDSO and see all the diverse ways amateurs are measuring doubles and making valuable scientific contributions.

Ed

#5 Rolex2

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Posted 02 November 2013 - 06:55 AM

Thanks to Michael, Roberto and zed.
Thanks for great information. Last night I read articles mentioned and looked at the books on Amazon. Not at the point getting technical, but I have all winter to study techniques. I found that a Meade sells a astrometric eyepiece. Looks like the micrometer eyepiece. I will order the eyepiece today plus Argyle's book...

#6 Ed Wiley

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Posted 02 November 2013 - 09:36 PM

Happy measures!
Ed

#7 Karl Fabian

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Posted 02 November 2013 - 09:44 PM

Meade still makes the 12mm illuminated Astrometric eyepiece. I bought one a year ago and they are still available for about $80. The reticle is similar to the no longer available Celestron microguide, so Double star measurements can be made on the micometer scale and PA determined by using the drift method to the outer degree scale.

Clear skies,
Karl

#8 drollere

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Posted 04 November 2013 - 06:48 PM

i think the celestron is superior to the meade, both optically and in the clarity of the etched measurement. (i've used both.) always check the used market (OPT sells some "pre owned" equipment, and of course there's astromart).

personally i think video would be the way to go, provided you like computer processing as the way to spend most of your time.

#9 Ed Wiley

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Posted 04 November 2013 - 10:02 PM

I agree with Bruce, especially if you objective is to make publishable measures. There are some limitations, for example, its hard to obtain good video when the difference in magnitude is greater than about 2.5 mags. Processing does take time but the results are good and the best (IMO) processing software is free.

Ed

#10 Astrodj

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Posted 04 November 2013 - 11:37 PM

Here is an interesting primer for some doubles worth tracking within one lifetime (that's all we get, right?).

http://admin.prairie...rg/dblstar1.htm

I realize your post was about eyepieces, but this is kind of apropo for some interesting short term targets. :grin:

Be sure to check out each of the five parts of the article.

#11 Astrodj

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Posted 04 November 2013 - 11:56 PM

A better link:

http://www.prairieas...double-stars...






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