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M20 Trifid Nebula in LRGBHa

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Posts Made By: jess tauber

September 16, 2005 09:59 PM Forum: Astro Binoculars

omcon 20x80

Posted By jess tauber
A pair of these (Antares?) binos just showed up on Astromart. Does anyone know anything about them? No other ads, nor posts the archived areas. Thanks.

Jess Tauber

September 20, 2005 03:19 AM Forum: Telescope Making

bino-periscope/rabbit ears variation

Posted By jess tauber
For my 6" bino project, I've been trying to figure out how best to fold the refractor paths. One idea that occurred to me today was to have the main tubes end-to-end, perpendicular to the facing direction of the viewer, like old fashioned military "rabbit ears" stereo range-finding binos when maximally unfolded. Large first surface mirrors would be mounted directly behind the objectives, giving a periscope effect.

Configured this way, most of the weight of the tubes could be much more distributed along the pivoting axis bar for altitude, end ep height would vary little. Admittedly this bar could be a bit unwieldy, as it would be almost twice the focal length. Anyway, I'd like comments about feasibility, or prior successes and failures of such a design if anyone has heard of them. Thanks.

Jess Tauber

September 27, 2005 04:32 PM Forum: Deep Sky Observing

M44

Posted By jess tauber
Hi all. Last night after the last dregs of Rita blew by here in northern New Jersey the sky was spectacularly clear of the usual suspects pollutionwise, and around 5am I could make out a number of the fuzzier patches in the sky much more clearly than normally is the case.

While scanning the area with my 20x80 binos I noticed a nice fat open cluster between the moon and (I think) Saturn. Is this M44? or is it something else? The stars in the cluster pretty nearly filled my field of view in the binos, if that helps.

Its the first time I've gotten a chance to use binos on this particular piece of space since getting back into astronomy, so I'm still learning the "lay" (if this topsy-turvy usage stands) of the sky.

So was I looking at M44?

Thanks.

Jess Tauber

October 4, 2005 06:18 AM Forum: Telescope Making

corrector plate costs

Posted By jess tauber
Hi again all. I'm interested in getting some broad picture of the relative costs of primary mirror versus corrector plate in catadioptric systems as aperture goes up. I'm guessing these costs diverge rapidly in the higher apertures, or we would see very large catadioptrics more commonly available. Has anyone out there seen figures? Thanks.

Jess Tauber

October 13, 2005 05:00 AM Forum: Telescope Making

polar scope

Posted By jess tauber
Hi again. I've a question about polar scopes for equatorial mounts- has anyone ever seen right-angled versions of these?

It's sometimes a real drag to have to get down on the ground to align these (especially for me, who has problems with my ankles and knees, though otherwise walking and standing aren't an issue).

A right-angled version might make the process a lot more painless (and perhaps a long light-guide to bring the image to a standing viewer even more so).

Anyone have any experience along these lines? Thanks.

Jess Tauber

October 14, 2005 03:06 PM Forum: Mounts

polar scopes

Posted By jess tauber
Hi folks. Have any of you ever seen (or heard of) a right-angled polar scope being used? Thanks.

Jess Tauber

October 25, 2005 02:27 AM Forum: Telescope Making

security mirrors

Posted By jess tauber
A couple of weeks ago I asked about using my 16 inch security mirror to make an all-sky scope.

Its mate in the case is concave (don't know figure yet), but about F/1. Does anyone have any experience (or perhaps has heard of people) utilizing such mirrors to make low power scopes? Or just the central portion? Even if it requires refiguring. Thanks.

Jess Tauber

November 2, 2005 04:46 PM Forum: CCD Imaging and Processing/Deep Sky

neural networks and focus

Posted By jess tauber
Hi- I'm a newbie to this particular forum, but interest in such things as night-vision eyepieces got me thinking about pre-processed images.

What I'm curious about here is focus. With the proper software (perhaps based on neural network or parallel processing?) would it be possible, hypothetically, and assuming pixel density was extremely high, and individual elements very sensitive, to process out-of-focus optical images and return focused ones? The default, first approximation assumption would be no astigmatism or chromatic aberration- but perhaps with color sensitive elements and modified software even these issues might be addressed? Diffraction spikes would be a separate problem.

Any ideas?- all this just popped into my head.

Thanks,
Jess Tauber

November 4, 2005 02:32 AM Forum: Telescope Making

off-axis refractor?

Posted By jess tauber
You've all heard of off-axis Newtonians. My question is, can an off-axis refractor work? The idea I have (lacking suitable ray-tracing programs to check it) is that by suitably tilting the objectives of a refractor, one may then fold the scope at odd angles and thus reduce the number of flat reflective surfaces. Final diagonals would reparallelize the light for ep's. Kind of a refractive Schiefspiegler. This is for a large binoscope.

Would this be feasible? Or would the image generated simply be distorted out of all recognizability by the time it hit the eye? Also, assuming it would work for a simple biconvex lens, would added elements (achromats, apo, etc.) render it unworkable anyway?

Thanks.

Jess Tauber

November 4, 2005 04:24 AM Forum: Astro Binoculars

knock-knock

Posted By jess tauber
Very quiet here- is anyone still around?

Jess Tauber

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