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dermarkus
journeyman


Reged: 10/18/07

Re: The Year-Long 60mm Telescope Challenge new [Re: Charlie Hein]
      #5785684 - 04/08/13 11:10 AM

I love that idea. I do not own any 60mm scope, but plan to use my 80mm refractor stopped down to 60mm instead.

Jim, is there any chance that you can provide that list in a format that can be imported into a spread sheet ? I was not
able to do that with the PDF.
The spread sheet would allow me to sort the objects differently. I live on 51 deg latitude and i will not be
able to see some of the southern objects. Sorting them allows me to filter on declination for example.

Thanks
Markus


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Jim Romanski]
      #5785736 - 04/08/13 11:30 AM

Funny you should mention the really big eyepiece on a 60mm. In my picture of my two 60mm scopes on an alt-az mount, the AT60EDT on the left has a 40mm Sterling Plossl (a little over 5-degree TFOV ) loaded in the diagonal.

When I was taking the pictures, I noticed that there was a lovely view of the sky and clouds overhead when looking into the objective, so I'd say no, so long as the eyepiece has an eye lens no larger than 69mm in diameter, it isn't cheating.

It also occurs to me that using the "Herschel Principle" (i.e., once you spot a target in a larger scope, your chances of seeing the same object in a smaller scope are better), participants using an aperture mask on a larger instrument may also have a decided advantage. Specifically they can locate and observe the target at full aperture and then put the mask in place to see if they can still detect it at the smaller aperture. IMO, that is not cheating either.

Because I will be using a side-by-side configuration for my 60mm scopes, provided that I align each saddle, I'll have the opportunity to put a 60mm on one side and a larger instrument on the other, and work back and forth between them. For especially challenging targets I may do something like that.

Regards,

Jim

Edited by jrbarnett (04/08/13 12:07 PM)


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: dermarkus]
      #5785762 - 04/08/13 11:42 AM

Hi Markus. I just updated post #5785633, above, and attached a Rich Text Format version of the cleaned up list. That should be pretty easy to dump into a spreadsheet. I had to select a skinny font and low point count to minimize the size of the attachment, so you may want to update the font size as well as the font itself for readability before moving it to a spreadsheet.

Regards,

Jim


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CharlieB
Carpal Tunnel
*****

Reged: 12/11/07

Loc: Southern NH
Re: The Year-Long 60mm Telescope Challenge new [Re: Charlie Hein]
      #5785916 - 04/08/13 12:47 PM

I'm well armed in the 50-60mm scope range, so I plan on participating as much as New England will allow. This will be a fun project.

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Chuck Hards
Post Laureate
*****

Reged: 05/03/10

Loc: The Great Basin
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5785982 - 04/08/13 01:12 PM

Quote:

The objective of the challenge is NOT to assemble a 60mm "best targets" list. Rather it is to push participants to try and find the limits of a 60mm telescope and, hopefully, come away with the sense that 60mm is larger and more competent than they expected or, if they cut their teeth with such a scope, more capable than they remembered .





Exactly. In fact my motivations are pretty selfish; I just want to see what the little scope can do now that I have decades of observing experience under my belt. Any contribution to cleaning-up or establishing some kind of list is a very distant second. I'm doing it just for fun.


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droidModerator
rocketman
*****

Reged: 08/29/04

Loc: Conneaut, Ohio
Re: The Year-Long 60mm Telescope Challenge new [Re: Chuck Hards]
      #5786079 - 04/08/13 01:43 PM

so there is a new pdf, or the original has been modified?

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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: droid]
      #5786141 - 04/08/13 02:25 PM

I eliminated target duplications that Thomas noted in the original pdf list embedded in the article, and attached a Rich Text Format updated version of the list a few posts up in this thread. I'd also like to update the pdf in the article and have sent Charlie an e-mail about the feasibility of doing that.

Regards,

Jim


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Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5786311 - 04/08/13 04:11 PM

Quote:

I should also clarify that the difficulty rating scale for DSOs in ST3 ranges like this, from easiest to hardest:

Easy->Obvious->Detectable->Difficult->Challenging->Very Challenging




Oh, that suddenly makes the difficult rating a lot more meaningful.


Clear skies!
Thomas, Denmark


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5787088 - 04/08/13 10:48 PM

I'm with you Thomas. The difficulty level names aren't necessarily logical or intuitive, but that's the way they rank in the application.

Incidentally, I also looked at a few 60mm to 70mm currently available scopes that might be nice options. The Meade NG-60 runs about $80 and looks like a modernized iteration of the classic alt-az mounted beginner's 60mm achromat.

A Vixen 70lf or Meade NG-70 or, stopped down a millimeter or two, also, might be an option as well.

I'm sure there are other options too.

Regards,

Jim


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Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5787374 - 04/09/13 04:45 AM

Quote:

Incidentally, I also looked at a few 60mm to 70mm currently available scopes that might be nice options. The Meade NG-60 runs about $80 and looks like a modernized iteration of the classic alt-az mounted beginner's 60mm achromat.

A Vixen 70lf or Meade NG-70 or, stopped down a millimeter or two, also, might be an option as well.




I've compared my 63mm Zeiss and my 72mm WO ED and the 72mm is quite noticeably brighter, giving it a real advantage on faint objects. If this is supposed to be a challenge for 60mm scopes, you should probably limit the max allowed aperture to ~65mm - 66mm (I am being completely selfish here, as this would still allow my 63mm Zeiss! ). A 66mm aperture would also allow the modern 66mm ED's and apochromats to participate.


Clear skies!
Thomas, Denmark


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Astrojensen]
      #5787811 - 04/09/13 10:57 AM

Yup. The range permitted in the article is any aperture from 60mm to 69mm, so the Zeiss is definitely a valid tool for the attempt based on the guideline.

In fact, I would even accept a well-constructed argument that a considerably larger catadioptric (such as a 90mm MCT) was inefficient enough to deliver actual light grasp on par with a much smaller unobstructed scope. If folks want to come up with a calculation of equivalent unobstructed light grasp for small catadioptrics, I'd have no objection.

If I do this with my Celestron C90 (aluminum with SiO2 overcoat on primary and secondary, multi-coatings front and back on the corrector) here's what I come up with: 90% reflectivity for each mirror surface, 99.5% transmission for each surface of the corrector (the corrector is not XLT coated, but rather standard Synta multi-coated), and a secondary obstruction of 10% by area, I get something like a 75mm fully multi-coated refractor equivalency. You'd still need to stop the average 90mm MCT down to meet the requirements, but by something more like 7-8mm rather than 30mm.

Regards,

Jim


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t.r.
Post Laureate
*****

Reged: 02/14/08

Loc: Upstate NY
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5788248 - 04/09/13 02:15 PM

Well, I have taken this challenge seriously after Jim suggested piggybacking my 60 on my primary scope so as to not miss out on valuable observing time with my larger scope. But, I feel I need to upgrade the focuser to accomodate the better 1 1/4" format eyepieces and really let my Towa lens loose and perform to it's full potential. So, just got off the phone with Dan at Crawmach about a focuser and extended flange assembly to get the extra long focal length required to reach focus with my Jason(has the inner drawtube which sags). He has done one of these "longer" focusers before and said once my measured specs are received, about a month build time. Of course rings will be ordered too!

http://www.crawmach.com/



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Astrojensen
Post Laureate
*****

Reged: 10/05/08

Loc: Bornholm, Denmark
Re: The Year-Long 60mm Telescope Challenge new [Re: t.r.]
      #5788641 - 04/09/13 04:30 PM

I've found a piece of aluminum tube that fits a custom cell for one of my Zeiss C63/840 objectives perfectly. Most interestingly the Baader/Zeiss M68 extension tubes also fit perfectly inside this tube, so that with a few such tubes, a readily available adapter and a few other off the shelf items, I can build a C63/840 with true 2" focuser.

I can already use 2" eyepieces on my Zeiss Telemator, but it does vignette a bit. The extremely fine focus of a 2" crayford with microfocuser would also be most welcome at high magnifications. I sometimes use 380x on my Telemator when studying planetary nebulae, so a superb focuser would not just be a rarely needed luxury, but a very useful item.

This idea has been ruminating at the back of my head since I found the aluminum tube, but perhaps I should see this project as a sign to do something about it.


Clear skies!
Thomas, Denmark


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: t.r.]
      #5788692 - 04/09/13 04:52 PM

Right on, Tim.

Sometimes you can find mass-produced R&P direct replacements for vintage 0.965" focusers too.

For example:

http://www.ebay.com/itm/Meade-1-25-60mm-Refractor-Telescope-FOCUSER-your-Eyep...

I'm using Anatres model FOCR2s on my three Cartons. I don't know if Antares offers these any longer, but of they do, they're actually a very smooth R&P unit. I think I paid about $29 each for these focusers.

Welcome aboard, matey!

- Jim


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Jim Romanski
Carpal Tunnel
*****

Reged: 01/02/05

Loc: Guilford, Connecticut
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5789961 - 04/10/13 10:39 AM

Quote:

In fact, I would even accept a well-constructed argument that a considerably larger catadioptric (such as a 90mm MCT) was inefficient enough to deliver actual light grasp on par with a much smaller unobstructed scope. If folks want to come up with a calculation of equivalent unobstructed light grasp for small catadioptrics, I'd have no objection.




Hmmm...what if I let my AT72 get REALLY dirty so that it cuts down on light throughput?


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Jim Romanski]
      #5790545 - 04/10/13 03:19 PM

Works for me Jim. Or perhaps add an 85% transmission ND filter to the diagonal.

- Jim


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Gardner
scholastic sledgehammer
*****

Reged: 01/19/04

Loc: New Hampshire
Re: The Year-Long 60mm Telescope Challenge new [Re: jrbarnett]
      #5791128 - 04/10/13 07:40 PM

This looks like lots of fun! Last year at our Messier Marathon I paired my FS60 and C9.25 on my G11. Lots of stuff is beyond the limiting magnitude of myself and the FS60, but it was fun to try anyway.

Would it be possible to publish the list as an observing list downloadable to Sky Tools 3? The double star list looks intriguing.


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jrbarnett
Eyepiece Hooligan
*****

Reged: 02/28/06

Loc: Petaluma, CA
Re: The Year-Long 60mm Telescope Challenge new [Re: Gardner]
      #5791544 - 04/10/13 11:12 PM

You bet, Gardner. I'm all Mac here at home, but tomorrow at work I'll fire up ST3 and upload the list in ST3 format to this thread.

Regards,

Jim


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Glen A W
professor emeritus


Reged: 07/04/08

Loc: WEST VIRGINIA USA
Re: The Year-Long 60mm Telescope Challenge new [Re: Charlie Hein]
      #5792017 - 04/11/13 09:51 AM

I've done a lot of those on the list, back when the 60mm was all I had. Hey, I figured it was a perfectly good galaxy telescope at the time. And, it's amazing how much I saw. I am not sure I would want to go back to one, though. I just don't get that much enjoyment from it, now. Glen

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Chuck Hards
Post Laureate
*****

Reged: 05/03/10

Loc: The Great Basin
Re: The Year-Long 60mm Telescope Challenge [Re: jrbarnett]
      #5792043 - 04/11/13 10:08 AM

Quote:

I'm using Anatres model FOCR2s on my three Cartons. I don't know if Antares offers these any longer, but of they do, they're actually a very smooth R&P unit. I think I paid about $29 each for these focusers.





It's a terrific focuser for a small refractor. I bought 5 of them some years ago, down to just two left that aren't dedicated to a project or already in use. IIRC, they had two models, one with a short drawtube, one with a long one. I grabbed the long ones. If anyone knows if they are still available, I'd sure appreciate hearing about it.


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