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Posts Made By: David Simper

August 25, 2006 09:47 PM Forum: Equipment Talk

2" Dielectric Refractor Diagonal

Posted By David Simper
Joe,

there are differences in the size, thickness of the mirror and in SV final checkup for collimation. I know that SV put a long effort in the design. The WO might look more "slick" but I would go with SV.

September 5, 2006 12:20 AM Forum: Reflectors

Looking for a lens maker

Posted By David Simper
What about Mr. Keller ?
http://www.astrooptik.com/sonstiges/Newton3Inch/NewtWynne.htm

September 12, 2006 06:09 AM Forum: Telescope Making

Structural Integrity Question

Posted By David Simper
You have seen CPT collapsible tubes ?
http://www.astronomy-mall.com/regular/products/cpt/

September 16, 2006 02:13 AM Forum: Equipment Talk

Johnsonian is Dead

Posted By David Simper
I am surprised that the business has not taken better off. The universal aspect of the platform was appealing in these days of travels for a dark sky. I was tempted for the 10% Labor's Day special on JMI website but than the concern about future support took hold of me. BTW, JMI was just rebranding the platforms, they were still produced in Loveland.

Floyd is right, I am not excited about lack of spare parts for my 16" Zambuto based Johnsonian goto. I have just received the repaired electronics box which gave up on me on the scope's maiden tour at the WSP. Without it, the remote collimation motors are inoperable. Still, the recollection of Omega Centauri on WSP in a binoviewer makes me soft...

It seems that Sam went a better paid route with his background in robotics: http://www.johnsonian.com/stealth/index.htm

The patents or license for his astro products is available.... :S


October 14, 2006 12:47 AM Forum: Chinese Optics Imports

Is Market Softening?

Posted By David Simper
I think the initial price was set to high. For couple hundreds more, you can have an used 4" TRIPLET Apo. The currrent pricing is fine at $999.

October 27, 2006 09:41 PM Forum: Refractors

Aries refractors

Posted By David Simper
Dmitri Kulginov said:

Do they exist? Does anyone have one?

Dmitri

They exist in rare samples like dodo, possibly Markus Ludes can give you more info.
E.g. here:
http://www.astromart.com/classifieds/details.asp?classified_id=189946
http://www.astromart.com/classifieds/details.asp?classified_id=93943

October 29, 2006 09:07 PM Forum: Reflectors

Collodion vs Alcohol/Distilled Water for cleaning

Posted By David Simper
I had good result working with colloidon in open space. Be aware that the vapors are heavier than air (I believe). Is the hood rated for solvents ?

In your specific case, I would do first the destilled water first followed by colloidon.

February 19, 2007 02:26 AM Forum: Refractors

ED Lens

Posted By David Simper
Something is wrong with your sample. At this diameter and F # it should not be there. I had a 114mm/F5.4 ED doublet which had a slight tinge only on the brightest objects.

May 9, 2007 05:29 AM Forum: Refractors

Re: Vixen ED102SS f/6.5 = doublet or triplet?

Posted By David Simper
When I had (your) scope I was intrigued by the same thing and inability to focus. Then the issue was corrected by removing the third >optional< element which was in. I clarified the text you are mentioning with the US Vixen rep at this time (before the TV association) and he agreed that the text is misleading and promised to correct it (what later happened, at least on the US site).

David

June 16, 2007 06:22 AM Forum: Equipment Talk

Red Tripod Light

Posted By David Simper
Just got it on Father's Day sale for ca. $16. Really cool.

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