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I agree, if you don't live under a dark sky a 6" instrument is an excellent choice. I built such an instrument

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/3720212/page...

with 160 mm f/6.5 oilpaced apo lenses, total weight 11.8 kg. Such an instrument can easily be transported to a dark side and hooked up to a mount. The big advantage compared to a bigger refractor with binoviewer, the large field, with 17 mm Ethos I get 1.6 degree TFOV at 65x maginification.

Thomas

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Thomas how much did your 6" bino telescopes cost to make?

Ken

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Ken,

I can not give an exact number, it took me almost three years to construct the instrument and I did not count all expenses. All in all, I guess the total costs were about twice as much as that of a high quality comercial 150-160 mm apo refractor.

Thomas

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Glen and Rich,

I never said collimation was IMPOSSIBLE with binoculars at magnifications above 50x, I just stated that it CAN be TRICKY.

There's certainly nothing "dangerous" about that statement whatsoever.

I'm surprised at you two not paying more attention to detail ! :-)

Kenny

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Nice project but a near perfect 16"-18" equatorial Newtonian with a high quality binoviewer will outperform it for $490K less.

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Assuming that this is correct, why does somebody who can affort it waists so much money?

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Nice project but a near perfect 16"-18" equatorial Newtonian with a high quality binoviewer will outperform it for $490K less.

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Assuming that this is correct, why does somebody who can affort it waists so much money?

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That is quite an assumption. Such a question risks opening the can of worms as to which telescope design puts up a better image. Frankly, my 105mm TMB-designed APO lens with AP diagonal shows an absolutely textbook star image. Observing double stars with it is a joy with good seeing, with or without a binoviewer.

I've yet to observe through a newt that shows such a sharp and perfectly collimated image with such ease and consistency, especially with increasing magnification, and I've used and owned Zambuto mirrors.

Not to mention the fact that you have no central obstruction from a secondary or diffraction spikes...

If I had the money I sure would enjoy that view!

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Michael Mc

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Nice project but a near perfect 16"-18" equatorial Newtonian with a high quality binoviewer will outperform it for $490K less.

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Assuming that this is correct, why does somebody who can affort it waists so much money?

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Because they can...

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Nice project but a near perfect 16"-18" equatorial Newtonian with a high quality binoviewer will outperform it for $490K less.

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Assuming that this is correct, why does somebody who can affort it waists so much money?

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Without going into the specifics of both instruments or their cost, you need to realize that for a given size exit pupil, the image with a binoviewer is only going to be half as bright as in a binoscope.

So at least on that parameter, take "outperform" with a grain of salt. However there are obviously very many other parameters that come into play in what somebody would call "performance".

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Nice project but a near perfect 16"-18" equatorial Newtonian with a high quality binoviewer will outperform it for $490K less.

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Assuming that this is correct, why does somebody who can affort it waists so much money?

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take any binocular (or optics) ever mentioned on CNs,
someone would think that it was a waste of money,
either too expensive or too cheap for their tastes

we are a diverse group
edj

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take any binocular (or optics) ever mentioned on CNs,
someone would think that it was a waste of money,
either too expensive or too cheap for their tastes

we are a diverse group
edj

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Isn't that the truth, and thankfully so. What works best for one person doesn't necessarily fit the bill for the next. Thanks for that reminder!

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