Re: (IAAC) FWD: What should I buy? (rich field scopes)
>. However, how many of them would you
>:consider to be "showcase" objects? Other than the Coathanger, the Alpha
>:Association, Coma Berenices star cluster, etc. that is. Aren't they really
>:more interest to experienced observers like yourself who have already seen
>:premiere deep-sky objects and are looking for new challenges?
>Dave, there are a lot more than the few objects you mentioned. You could not
>appreciate or fit most of the open clusters that *I* love into high mags....
>M44 (Beehive) is one as well as Pleiades (45). Add to that the full
>Andromdex Galaxy, Helix Nebula, Pinwell Galaxy. M6 and M7. M17 and M16.
>You could not see the spiral stars streaming out of M11 with higher power.
>I guess it's all objective, but in my mind LOTS of objects need the lower
You failed to read the entire message or missed its intent. The DSO's that
you mentioned are all well known Messier and NGC objects, not objects in
the Barnard, Collinder, Sharpless, Melotte, etc. catalogs that Sue was
addressing. Besides all of your objects except M31 will "fit" into a low
power field of view of most small, fast telescopes. Sue was talking about
small, rich-field telescopes (say a Pronto with a 35mm Panoptic) that have
LARGE fields of view, for telescopes that is.
Have you ever seen any of the objects that you mentioned through a large
telescope equipped with a 2" wide-field eyepiece? You'd be surprised at
just what will fit into the field of view. (Certainly the Helix will since
it is only about 30" in size.) And believe me when I say that I have seen
those objects and others that are similar with instruments ranging from
opera glasses and Sard 6x42's (with an incredible 12 degree field of view),
Fujinon 7x50's, Celestron Ultima 8x56's, Celestron Pro 9x63's, 10x50's
(Orion, Swift, Nikkon, Pentax, etc.), Fujinon 16x70's, Celestron 20x80's,
Miyauchi 20x100's, Orion 25x100's, Nikko 20x120 naval binoculars, Tele Vue
Prontos and Genesises (and the prototype 140), 3.5" Brashear and a number
of other antique refractors, 4" Astro-Physics Travelers (and 6" and 8" A-P
Starfires), 5" D & G Optical refractors, 6" binocular telescopes, the
Schupmann 13" medial refractor, 4.5" to 20" reflectors, and so on up to
24", 25", 32", 33" and 36" Dobnewts. (The best view of M15 that I ever
had was through the Sproul Observatory's 24" Brashear refractor at 300+
The point that I'm trying to make is that high power deep-sky observing is
just as valid and useful, depending upon the object and aperture of the
telescope in question, as low power observing with the typical fast
telescope is. Look at the second paragraph of Al Nagler's telescope myth
which addresses the 7mm exit pupil question. You should also see Roger
Clark's _Visual Astronomy of the Deep Sky_ which is concerned with the
optimum magnifications needed for viewing various DSO's.