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Posts Made By: James DellaPenna

September 1, 2004 12:01 AM Forum: Equipment Talk

CG5 GT capacity

Posted By James DellaPenna
Anything over the 9.25 SCT or 6" refractor is pushing it too much. Even those two models are pushing the limit. Even with a rigid tripod such as the Eliminator that much load will very easily be influenced by a slight breeze.

October 7, 2004 08:25 PM Forum: Equipment Talk

Re: overseas equipment like this available in US

Posted By James DellaPenna
Darrell is right. Why go overseas when we have excellent affordable 2" diagonals with compression rings and 1.25" adapters right here.

November 18, 2004 09:33 PM Forum: Equipment Talk

Carbon fiber tube or aluminum SCT?

Posted By James DellaPenna
In prior forum discussions it seems that the only advantage that anyone could claim with absolute certainty was that the fiber tubes looked cooler, as Floyd stated. Other advantages seemed more a product of advertising hype than anything of real value.

November 28, 2004 03:19 AM Forum: Equipment Talk

Looking for Right Angle Finder suggestions

Posted By James DellaPenna
I have the Orion 9x50 correct image finder. Optically it is fine for my purposes but mechanically it has a major drawback. If the diagonal portion of the finder is rotated to a more comfortable position it loses its alignment. Do all right angle finders do this or is it just Orion?

The only way I can use this finder is to make sure the diagonal is threaded on all the way tight and just position the finder tube in sort of an intermediate position, align with the telescope and just live with that position. I thought you were supposed to be able to rotate the diagonal a bit for convenience without losing alignment but apparently that is not the case.



December 4, 2004 03:17 PM Forum: Beginning Astronomy?

Re: ALERT: Do Not Pay to Name a Star

Posted By James DellaPenna
Jon,

Do you think it's a good thing to sell land on the Moon? Ethically I don't see any difference between this scam and paying to name a star.

January 3, 2005 09:18 PM Forum: Equipment Talk

meade's new ad.

Posted By James DellaPenna
My guess is a new GPS model that sets itself up on site (no hands).

For an extra $495. you can option for an owner's manual that claims to be complete, a plastic do-it-yourself tool kit, a box of spare parts that don't work, plus access to a new customer service hotline manned by the "no" guy in the Capital One ads. But then, I am biased.

February 3, 2005 08:32 PM Forum: Equipment Talk

newbie needs help: which scope?

Posted By James DellaPenna
Travis,

Tough choice. The Nexstar Go-To beats the LXD55 Go-To hands down. Unfortunately, the LXD55 has numerous issues regarding accuracy and consistent dependability. It's a great mount if you like to work for the mount instead of the mount working for you!

On the other side, the SN8 has 2.5 times the light gathering power of the 5". In this respect there is no reasonable comparison between the two scopes. Aperture rules.

The closed tube Schmidt-Newt that Meade sells is going to require a longer cool-down time than a straight open tube Newtonion. Check out Celestron's 8" Newtonion on the CG-5 Go-To mount. I think you would be much happier with that set-up if it would fit your budget.

February 27, 2005 03:59 PM Forum: Equipment Talk

Need Help with a Birthdate for a C8

Posted By James DellaPenna
Don,

You can try Celestron but it has been my experience that they do not keep a record of manufacturing dates by serial numbers. There is a history of Celestron SCT's at http://home.att.net/-telescopebluebook/sct/celestron.htm that might help narrow it down a bit as far a span of years. This will not get you where you want to be but may be a start.

March 6, 2005 01:31 AM Forum: Equipment Talk

High power with binoviewer in short refractor

Posted By James DellaPenna
Dave,

How often do you expect seeing conditions to permit 300x viewing without image breakdown, even with a 94mm APO?

Is not the theoretical limit of your scope around 200x in pristine conditions? A pair of 10mm EP's will put you at 179x, not 150x. Your effective focal length with the 2-arm power switch will be about 1792mm. Remember, your Denk automatically increases the power of any EP by about 12% simply due to the extended optical train. Whatever power a particular EP normally gets in mono mode will yield 12% more in a Denk bino. That's the number you multiply by the 2.5 to get true maximum power with the power switch.

This extra 12% is one of the most commonly misunderstood aspects of binoviewing. Other brands may have slightly different percentage factors. 12% applies to Denkmeier.

I have the Denk Standard and used to have a pair of 10.5mm XL's which worked fine (no aberrations).

June 30, 2005 12:56 PM Forum: Binoviewers

Binoviewer Forum rules

Posted By James DellaPenna
Don,

A hearty welcome as the new moderator.

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