Posts Made By: George Normandin

I see a notice on the Denkmeier website that sez:

"Our new .87X Power x Switch Reducer System for Newtonians for the first time ever. Specially designed to work with our D21 Eyepieces, this system will allow them to operate as if they were 24mm 65 degree eyepieces in this very new Denkmeier system......"

I believe I've read that Russ had this system at the WSP this year. Has anyone looked thru this new "reducer"? If so, what did you see?

George N

I have an Obsession 20 equipped with the old JMI NGC-MAX DSC unit. Following the practice I’ve seen others use I’ve always spent 10 minutes or so struggling to level the mirror box with a bubble level and little wood shims each time I’ve set up the scope under the assumption that this is needed for accurate pointing. However the manual does not discuss this at all. Has anyone tested to see if very accurate leveling is needed for DSC accuracy with a Dob?

George N

See: http://www.televue.com/engine/page.asp?ID=2

I just received an e-mail (11:30 am EST 12/22/08) from my friends at Kopernik Observatory (www.kopernik.org) asking for help examining a possible meteorite fall from a few hours ago. My question is: How do you tell a meteorite from some other falling object? Other than checking for burn evidence, magnetic and metallic properties and possible radioactivity, what else should we check to determine what this “rock” is?
Here’s want I know so far:

“We just got a call from emergency services in Port Crane, New York. He said this morning a couple (names deleted) were eating breakfast and a loud crash sent them to their garage, where they say a big rock had crashed thru the window and made a hole in the concrete floor. The owner said the angle of trajectory was such that it couldn't have come from Earth, and saw no footprints or other signs nearby.”

George Normandin

Dave Mitsky said:

The 2006 Stellafane turned out to be a very enjoyable one. Friday night was quite good, which surprised just about everyone given what the varying forecasts had been..... Dave Mitsky

I was one of “the surprised” by the clear sky on Friday, considering the poor forecasts. At 4:00pm I had just helped a guy set up his 25-inch Dob and was talking to a ‘reporter’ from Vermont Life, when it started to rain. I’m very reluctant to touch someone else’s scope, but I was going to cover the 25, when I saw the owner running up. I helped the guy get a tarp over his scope.

It started to clear around an hour or so before dark. A couple I’ve know for years and I both own Obsession 20’s. We had a frantic time getting them both out and set up (in the camping field north of the food tent) and cooled down in time to start observing as that blaze of Milky Way came out. It was neat to have two 20’s set up side-by-side so that we could cover different parts of the sky. I went all night on Friday/Saturday so I never lasted long enough to see the clear sky on Saturday/Sunday. However, one friend said that it never really cleared at Stellafane until well after mid-night. Earlier we had “cruised the sucker holes” with a 6-inch Dob. It was clear enough during the daytime to have some good views of the sun with my PST.

One other thing I’d like to mention about Stellafane 2006: That new building is fantastic! A big improvement over the old tent! …..and oh ya, I won a price for the first time in 11 years of going to Stellafane – but it was just a copy of a Sci-Fi novel signed by the author, not one of the ‘Al bags’ full of Naglers!!

George Normandin

Mike Alexander said:

I know that many recommend that you put your scope outside at least one hour before you use it to allow it to come to thermal equilibrium with the outside temperature, but, when you do, you run the risk of dew formation because everything is the same temp. I live in New England and this past week we had 3 nites where the transparency was above average, but, even witha flexible Astro-Zap dew shield on my scope, it seemed to get covered with dew in almost no time, as humidty was over 85%.
What is the answer to the dew problem?

Thanks.....Mike

Mike,

You didn’t mention the type of telescope you have or if your dew shield has a heater. However, assuming that you have an SCT: On high humidity nights you need to start running heat as soon as you put the scope out, with the heat at a high setting. Once dew forms, most dew heaters can’t get rid of it. If you are at home with access to AC power you can use a hair dryer to remove the dew. While running heat might slightly degrade the scope’s performance, at least you are observing – versus not observing at all!

BTW, I live in NY and with this year’s rain (and flood) the ground is soaked. The shroud of my Obsession Dob is generally soaked before it is even dark enough to observe. However my Kendrick dew heaters keep the secondary, Telrad, eyepieces, etc, dew free.

George N

Scott Ayer said:

Has anyone seen any of these new 5" triplets yet?

I'm interested in this scope also. I've not seen any store saying that they have one. I recently e-mailed one place close to me to let me know when they are in stock and didn't get a response. I hate to start rumors, but I seem to remember someone quoting a Meade rep with saying they hope to start shipping in January. If it happens like the 80mm, Meade will send a few units to the stores near their location for the first month or so.

George N

Donald Durbin said:

......To build an OCA for a Newtonian telescope, screw the focal reducer into the Burgess unit, screw the extension tube into the focal reducer, screw the Barlow element into the extension tube. This assembly came to focus very easily in my 8" Orion Atlas.....

Don,

I'll give it a shot! Thanks for the idea.

George N

Jeff Young said:

I'm trying to determine the best way to upgrade my 16" Meade SCT OTA. ..... Let's also assume 80% deep sky and 20% planetary.. .[/B]

-- Jeff.

Jeff,

Let me add a little practical experience: I regularly observe with an Obsession 20 (15% obstruction - Torus primary), OGS 20RC (35% - Star Instruments), C-14, and an A-P 6" F/12 APO -- all within feet of each other. On deep sky there is NO difference in what the Newt and RC show. On planets the Obsession 20 kills the others.

You really need to consider many issues here: like percent of illumination across the field, the coma-free performance of the RC, the light loss of the SCT's corrector plate, etc.

My advise would be to fix what ever is wrong with the SCT, but otherwise, for visual deep sky observing (while sitting) I'd advise a Classical Cass with premium optics and a secondary large enough give decent illumination across the field. It also should be a good planetary scope.

George N

Jeff Young said:

.....
Of course some of the obvious targets come up: the Rosette, portions of the Veil, the Leo triplets, M42, etc. Many of these don't even fit in the field at f/11, so doing a bit more panning at f/14 shouldn't be that big a deal.

But there's another class of target where I needed the higher light density of a lower magnification and larger exit pupil. Examples include the Headphones, NGC2403 and Thor's Helmet. At f/14, even a 31T5 gives barely more than a 2mm exit pupil. I can go up to something like a 55mm Plossl for 4mm, but I'm not terribly fond of the soda-straw views it gives.

What do folks with classical Cassegrains do on low-surface-brightness targets?

-- Jeff.

Jeff,

I've used an old VERNONscope 40mm Erfle (70 degree field) on long focal length scopes (C-14, A-P F/12 refractor) and it works well. For many years at Kopernik Obs we had a Tinsley 12.5" D-K Cass that came with a 101mm eyepiece. You may also be able to find a VERNONscope 48mm eyepiece. However, I'd just forget about observing "big" objects with the scope and add a 4 to 5 inch refractor to your setup. You could even mount it on the classical Cass. BTW, you can get a classical Cass from Optical Guidance Systems with Star Instruments optics. There are several others making them also.

George N