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Posts Made By: James DellaPenna

January 5, 2020 07:27 PM Forum: TeleVue

PCV2000 Visual Paracorr question

Posted By James DellaPenna

My question answered on the Equipment Forum.

June 8, 2020 08:32 PM Forum: Equipment Talk

Which f/6.3 focal reducer?

Posted By James DellaPenna

I'm in the process of acquiring a CPC 1100 and will want an f/6.3 reducer, both for regular viewing and binoviewing.
The most popular brand seems to be the Celestron 94175 reducer.  Unfortunately, it costs about 50% more than the apparent equivalent in Meade, Antares, etc.  Is it really 50% better or is this higher price simply something Celestron has always been able to get away with?  Opinions, please.

June 9, 2020 11:33 AM Forum: Equipment Talk

Which f/6.3 focal reducer?

Posted By James DellaPenna

Thank you, Rod.  That was a very helpful discussion reference for the f/6.3's.  I appreciate it.

September 30, 2020 01:21 PM Forum: ASTRONOMY

Generally underwhelming results from 8” LX200 classic

Posted By James DellaPenna

When was this scope last properly collimated?

October 6, 2020 05:57 PM Forum: Eyepieces

Bright eyepieces?

Posted By James DellaPenna

You did not indicate the f-ratio of your 120mm refractor.  I'm assuming it's something like f/8.  If that's the case, the 3.5mm Nagler is yielding 274x, which is pushing it quite a bit for that scope.  Your view is guaranteed to be dark w/ that eyepiece.  The 6mm would yield 160x, which is likely closer to the practical limit (for nice views) but may still be a bit dark.   Unless you have a $6,000 scope and pristine dark skies I would ignore the old guideline of 50x per inch of aperture.  In practice it's more like 25-30x per inch of aperture for acceptable views.

November 9, 2020 06:16 PM Forum: Home Observatories

A bit of rolling roof advice needed.

Posted By James DellaPenna

At 75 years I've reached the point where lugging around scopes is no longer fun.  Instead, I've decided to cut a few trees and build a simple 8' x 8' shed w/ a roll-off roof for my CPC-1100.  The roof will have a low pitch of lightweight metal sheathed construction.  I've seen photos of a number of roofs w/ large 4" caster wheels riding in aluminum channels but the cost of that seems totally unnecessary for my purposes.
In attempt to save money I'm leaning towards 2" metal roller casters rolling on 1" or 1.25" Schedule 40 PVC pipe. 
An alternative form of track I've seen was a 3-4" wide galvanized strip with a raised center shaped to accommodate the rollers but cannot find out anything about this product.  It seems it would be a little more stable and perhaps much easier to install than PVC pipe.
Anybody know what this product is called and where to find it?  Any other advice appreciated. 

November 14, 2020 06:50 PM Forum: AstroMart FAQ

'Featured photo' shows the roof of my house????

Posted By James DellaPenna

I have not tried this myself but try just searching archives for G11 without the suffix.  Sometimes adding too much information just shuts down any useful search.

November 30, 2020 08:09 PM Forum: Binoviewers

Denkmeier ll with TV Genesis non sdf question

Posted By James DellaPenna

The binoviewer does not require an OCS (optical corrector system) for use with an SCT.  Hewtonian reflectors or refractors require the OCS lens to bring you to focus.  For your refractor, it usually screws into the telescope end of your diagonal.  Whoever sold you the Denk II should have included the OCS, which would automatically come with it when purchased new.  Exception:  If it was purchased direct from Russ at Denkmeier and Russ knew it was for an SCT, the total price may have been adjusted to eliminate the OCS, since it was not needed.
You will need to contact Russ Lederman at Denkmeier to obtain the OCS.

July 2, 2021 07:44 PM Forum: Telescope Making

What Do Amateurs Do For a Living?

Posted By James DellaPenna

There really is no limit to the backgrounds of amateur astronomers.  Many years ago I operated a debris hauling company.  My astronomy club did lots of public outreach.  One of them was an annual 3-day outdoor science camp for public school 5th graders.  Prior to letting the students look through my scope I always did a verbal presentation on an astronomy topic.  After completing my presentation a lady parent serving as a camp proctor was so enthralled with the presentation she asked if I was a science teacher.  I said, " no Mame, I haul trash!"  She went silent and did not know what to say. I always got a kick out of that.
Jim D.