Posts Made By: Larry Seguin

I've been following your reports on La Palma, diffuse nebula, and open clusters. You guys are a wealth of information on objects to look for, filtering techniques and magnifications to use. Thanks so much for taking the time to make these reports...I've been taking a lot of notes!
Larry

I was viewing the Moon tonight, and noticed some dark patches. They lie east of Copernicus, in Mare Insularum. Anybody know what these are?

Roland,
Thanks for the simulation of the view of stars as they would appear through various designs of lenses-very enlightening! Are you aware of anyone having done that in a comparison between reflectors and refractors? In other words, how would the airy disc and diffraction ring look through a well figured mirror as opposed to a well designed triplet?
Thanks for any help you can offer.

Most folks who are at this hobby for any length of time come to the conclusion that no one scope does it all. That's why we keep buying and selling them! That's why most of us develop a "herd" of them, each with it's own particular use. My current setup seems to satisfy all of my needs for now (riiiight).
For deep sky: a 14" f/4.7 dob. Enough aperture for the faint fuzzies, short enough to do my viewing feet-on-the-ground, light enough to pick up and move if I need to fully assembled.
For planetary/lunar: an 8" f/6 dob. enough aperture for DSO's if I need to, enough resolution for planetary detail, easy to transport, works GREAT with binoviewers!
For wide fields and solar: A short tube 80. One hand portable, easy to use on a camera tripod with bogen head, did I say WIDE fields? With the other quality of views in the other scopes I don't need an apo at this size (riiiight).
No matter what I'm looking for or at, I can shoose one of these guys and get there.
Any one care to chime in on what your current/favorite/ideal setup would be or is?

A word in defense of the oft maligned zoom eyepiece. I was looking for one to use with my ST-80, wanting to keep the entire kit as grab'n'go as possible. Tried one of the less expensive brands first, and it wasn't too bad. Then I picked up one of the Vixen LV zooms, having been very satisfied with the performance of their LV line of eyepieces. I must say that I have been very impressed with the performance of this zoom! I compared it with some Elite plossls I use in my binoviewers, barlowing them to achieve the higher magnifications the zoom would provide. Very nice, indeed! To my eye, I can't really discern any difference in on axis sharpness, brightness, or contrast between the Elites and the zoom. Off axis is always a little soft on an f/5, but in the sweet spot this zoom really performs. I've heard that there may be some variations in these units, but the sample I have has very sharply revealed faint stars in the Pleiades, the Double Cluster, and the Trapezium in Orion. the Orion nebula itself looks just as bright and detailed through the zoom as through the plossls, and it performs side-by-side with them on the moon. Ergonomically I'm very satisfied with it. The field is listed as being the same as in the less expensive units, but to my eye it just looks larger at the short end of the zoom's focal length. The eye relief is just about perfect for me, and the zoom action has been very nice, not stiff at all, even when the temperature dips down into the twentys and the teens. All in all, I find it very eay to recommend this zoom to anyone who has been thinking about one, but been put off by some of the reviews they may have read. Out of the branded units it's supposed to be identical with, it is the least expensive option of them all. I'll be keeping mine for certain!
One very happy camper!

Had three of these in 2000, but sold them. Now I'm thinking of revisiting them, but I keep hearing reports of differences in optical performance between the various focal lengths. Question is: Is there anyone out there who currently has at least a couple of different focal lengths in their possession and can comment on these "differences"? Any help is appreciated?

That's what I'm looking for. Doesn't have to be wide field or long eye relief, I've already got that. What it has to be is the brightest, highest contrast eyepiece, specialized for plucking faint details out of galaxies and nebulas. What have you all found that would fit the bill? What have you tried that didn't? Thanks for any insights you may care to share!

Thanks to everyone who responded! It looks like I'll be picking up a partial set of high performance orthos to squeeze out that last little bit of contrast on DSO's. One more question: has anyone noticed similar effects in barlows? That is, do some barlows have better contrast/brightness due to coatings or design? Seems like it would be a shame to park a bright contrasty ortho on a barlow to get a higher power with good eye relief and then lose the brioghtness/contrast.

Thanks to everyone who responded! It looks like I'll be picking up a partial set of high performance orthos to squeeze out that last little bit of contrast on DSO's. One more question: has anyone noticed similar effects in barlows? That is, do some barlows have better contrast/brightness due to coatings or design? Seems like it would be a shame to park a bright contrasty ortho on a barlow to get a higher power with good eye relief and then lose the brioghtness/contrast.

Is any one finding nebula filters useful with their BV's? I'm using the BO/Orion/WO type unit with a Siebert oca: 22mm clear aperture, operating around 2X or so. I haven't been finding them very useful, and wondering if I'm missing something somewhere. Maybe it's that--at that magnification--I'm hitting the oft-cited 2mm exit pupil where I've found filter usefulness to start dropping off anyway. Just curious as to what the rest of you all have found.