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Philip Imbrogno

M 33

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Posts Made By: Philip Blanda

June 1, 2006 06:36 PM Forum: Binoviewers

Baader Mk.V and mirror T-2, part 1.

Posted By Philip Blanda
It has always been a small niggling concern of mine the Baader prism T-2 diagonal that came with my Baader Mk.V might be introducing a small bit of colour and spherical error when used with my f/6 130mm APO and f/5.8 105mm APO.

I saw that Baader has available a T-2 Maxbright mirror diagonal. Hmmm, I thought, let's get it and see.

Comparing it to the T-2 prism unit, it was a very little bit larger. It would not come to focus on an AP 130EDF and 24mm Pans. Uh-oh. A quick order to AP for their 2" thin adapter (ADA2013) did the trick.

Last night I used the 130EDF, 24mm Pans and 13mm Naglers with the Baader Mk.V and the mirror T-2 diagonal and thin adaptor. Before the mists rolled in the views of the Moon was very nice indeed. I was happy to be able to reach focus.

Next up is seing if I can reach focus without the 1.25" glasspath and seeing if I really notice any correction improvement from the mirror diagonal vs. the prism diagonal. I think it may be more a theoretical improvement rather than a practical, but we shall see.

Philip

June 6, 2006 05:13 PM Forum: Binoviewers

Optical quality Matters Not?

Posted By Philip Blanda
I have seen in several places the assertion that the optical quality of binoviewers does not matter in a practical sense. As I understand it the claim, it is saying that ALL prisms and beam spliters from the least expensive to most expensive binoviewers currently extant are above the minimal quality which would be visible to any observer.

I do not agree with this claim in principle. My hypothesis is that the surfaces of the beamsplitter and the lower portions of the prisms are far enough from the focal plane that a good portion of the surface is used to form each point on the image. Hence, quality matters and differences can be seen.

I do not have more than one binoviewer, so I cannot test either hypothesis.

Anyone done such a test at high powers (i.e. smaller focal length eyepieces) or have anything to add as to why one might or might not see any such differences?

Philip

June 28, 2006 07:01 PM Forum: CCD Imaging and Processing/Deep Sky

Bandpass shifts & Ha filters

Posted By Philip Blanda
How fast can one image with the various Ha filters before the bandpass shifts out of the Ha region, or at least degrades to the point of noticing? The fastest I would ever be imaging at if f/4.35 and more typically in the f/7.5 to f/4.5 range.

This is based upon my belief that the various Ha imaging filters are interference based rather than dye based.

I've decided to try my hand at imaging again (last did it in ~1999) and thought I would try some narrowband luminence techniques with which some folks have produced awesome images. Don't laugh but I'm dusting off my old SBIG ST-5C. 8O

July 19, 2006 12:26 AM Forum: Refractors

TMB 130 f/7 $3790

Posted By Philip Blanda
TMB 130 f/7 $3790 - see http://tinyurl.com/rykxl

I believe these are made in China. TMB seems to be undercutting himself quite nicely with these - I wonder if this has something to do with StellarVue getting lenses directly from LZOS without any TMB design? Will APM go it's own way now? Will the quality of these scope be up to the LZOS quality?



September 1, 2006 01:58 PM Forum: Star Parties

CSP or South Jersey Star Party?

Posted By Philip Blanda
I have gone to the South Jersey Star Party 4 times now, but I am considering going to the Connecticut Star Party this September. How dark as the skies at the CSP? How are the people (the SJSP has a nice friendly bunch of folks)? Is the CSP family friendy, that is are kids frowned on or encouraged?

Thanks,

Philip

September 26, 2006 03:11 PM Forum: TeleVue

Re: NP127 Price Drop?

Posted By Philip Blanda
The NP-127 occupies a special place in the 5" APO pantheon. At 14lbs it is by far the lightest of the currently available high quailty 5" APO's (SV5 is 21lbs, TMB/APM 130 CNC-LWII is 20lbs, TOA-130 is 22lbs, TEC-140 is 18lbs). This extreme light weight translates into the ability to use lighter mounts which increases portability.

Even the original version is well suited to astrophotography up to 35mm chip sizes, the iis version address even larger sizes (and reduce the light falloff on 35mm size as well). All the other 5" scopes require an additional field flattener.

For someone who is looking for a visual, portable lightweight 5" APO, the NP-127 has to be at least near the top of a very short list.

Philip


September 28, 2006 11:07 PM Forum: APM

Re: TMB 152 Out There?

Posted By Philip Blanda
I spent some time at last years Black Forest Star Party looking through a TMB 152 in the classic silver CNC tube with a Baader Mk.V Binoviewer. Very nice views, I remember in particular how nice the M31 looked.

Philip

October 2, 2006 07:43 PM Forum: TeleVue

Re: NP-127is

Posted By Philip Blanda
Both are extremely well made telescopes, designed and executed to give all that can be gotten from their aperture size. Which means that the TEC-140 will throw up a slightly brighter image on DSO, show slighty fainter stars, and resolve slight finer details on the Moon and planets.

The NP-127iis will be lighter, slightly easier to mount, and have a flat field for astrophotography without having to purchase a seperate flattener.

The question is, which attributes do you value more?

Philip

October 10, 2006 02:04 AM Forum: Equipment Talk

Meade being sued for R-C moniker

Posted By Philip Blanda
I saw a message in the Yahoo "telescopes" forum that Meade is being sued by RC Optical Systems and Star Instruments for "a scheme to defraud or obtain money by means of false or fraudulent pretenses or representation, by which they falsely represent to the public generally and to amateur astronomy enthusiasts in particular that the Meade RCX400 Series and Meade LX200R
series telescopes are Ritchey-Chretien telescopes incorporating Ritchey- Chretien optics".

The message was made by a very respectible optician and telescope maker so it appears to true. For those who belong to "telescopes" it is message #124283 and originally was posted to the "RASCals Discussion List" whatever that might be.

Philip

January 10, 2007 11:29 PM Forum: Solar System Observing

Comet from a train station, Jan 10

Posted By Philip Blanda
I caught it naked eye from the Hoboken Train Station. Got off the light rail at 5:10 and had to catch the "heavy" rail 5:26 out again. In between on the waterfront at the long slip is a good western horizon. The comet was visible in the red of the twilight. Condensed nucleus evident ans a long and what appeared to be forked tail.

Pretty cool indeed and darn bright for being visible in such bright twilight.

Philip

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