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Posts Made By: Vahe Sahakian

April 3, 2004 03:43 PM Forum: Equipment Talk

To all you experts!!!!!!!

Posted By Vahe Sahakian

Over and above all the good advise that you have received add one more; if your scope had not reached full cooldown you pretty much can expect blurry images at any power.

Thanks,
Vahe

April 25, 2005 03:39 PM Forum: Equipment Talk

Feedback, Mewlon/AP/TEC

Posted By Vahe Sahakian

"the only other options would probably be a Tec 160/AP 160, but if I am reading the stuff correctly the TEC is 50% more than an AP? "

If I am not mistaken TEC160 comes in two versions, the ED version is a little less expensive than the AP, the fluorite version is considerably more $$ than the AP160. Either of the two scopes are too large for a G11, as for GM8 you can forget it.

Thanks,
Vahe

July 31, 2005 07:05 PM Forum: Equipment Talk

HELP - Truss Dob v MakCass

Posted By Vahe Sahakian

For every large aperture Mak owner there are at least 10,000 Dob owners out there, so do not be surpised of the overwhelming recommendation to go with a Dobsonian.

Thanks,
Vahe

November 20, 2005 07:27 AM Forum: Equipment Talk

Diffraction Limited Optics

Posted By Vahe Sahakian

For whatever its worth here is one more take on the definition of diffraction limited optics; Personally I do not consider Rayleigh 1/4 wave criteria applicable to most well corrected scopes that are availably to amateurs today, the definition simply implies that telescopes wavefront errors are small enough that diffraction effects limits its performance, in layman's term this means optics are as good as it gets.
The 19th century Rayleigh 1/4 wave criterion applies only to unobstructed telescopes, telescopes with central obstruction require much higher quality to deliver performance that a 1/4 wave refractor is capable of.
As for Ceravolo experiment and its conclusions, most participants in that experiment had a very short time to guess the optical quality of those 6" reflectors, there are many variables that can affect the conclusions including seeing and persons unfamiliarity with that particular type instrument.
I can personally tell the difference between 1/4, 1/10 or even better wavefronts up to 6" aperture simply because 6" and smaller apertures, when seeing allows, do reach their maximum potential frequently, on larger apertures it becomes extremely difficult if not impossible to see the difference due to seeing limitations.

Thanks,
Vahe

November 25, 2005 03:33 PM Forum: Equipment Talk

so many tec maks, so little cash

Posted By Vahe Sahakian

TEC6 was introduced a little before TEC140, many who had TEC6 and also bought the 140 are keeping the apo and selling the Mak. If you want the best little 6" Mak get one while they are being offered on Astromart.

Thanks,
Vahe

March 12, 2006 07:32 AM Forum: Astro-Physics

155 astrophysics f9 w/ G11 losmandy

Posted By Vahe Sahakian

I would put the EDT on Astromart Auction, it is the best visual 6" planetary scope that AP has produced, if it is in a very fine condition it will probably go for more than 8K.

Vahe

May 11, 2006 08:10 AM Forum: Refractors

Best Planetary 4" refractor?

Posted By Vahe Sahakian

Every scope regardless of aperture will show something when it comes to planets, if you expect some serious detail the minimum aperture for a refractor is 5", the 4" simply does not have the resolution needed for the "finest planetary detil", and will run out of light at higher powers when combined with a binoviewer.

Thanks,
Vahe

August 24, 2006 09:12 AM Forum: Equipment Talk

Popp Maksutov

Posted By Vahe Sahakian

Generally speaking in a Mak Cass half the effort is in optics and the other half belongs to the mechanical parts. Since you have assumed responsibility for assembling the mechanicals, do some serious homework on cooling aspects. Your legendary optics will not produce legendary images unless you control all thermall related issues.

Thanks,
Vahe

September 3, 2006 06:26 AM Forum: Equipment Talk

Meade 6" SCT?

Posted By Vahe Sahakian

Meade has copied pretty much anything and everything that Celestron has produced in the past, I do not think that this will be an exception.

Thanks,
Vahe

September 7, 2006 02:05 PM Forum: Eyepieces

Long fl orthos

Posted By Vahe Sahakian

There probably is a very low demand for long F ratio Orthoscopics, to most Ortho's are eyepieces for planets and to get a reasonable magnification with your typical fast telescopes that are so popular these days there is very limited use for 25mm and longer Orthos.
I use a pair of 34mm ZAO's in a binoviewer which produces 185x with my TEC Mak, enough power to be used as a planetary eyepiece, has a very narrow field but is a superb performer.

Vahe