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Posts Made By: Lorne Johnson

September 5, 2006 02:16 PM Forum: Eyepieces

35mm vs 31mm.

Posted By Lorne Johnson
In an f 9.8 refractor (sounds like a televue 102, or an achromat), there is very little significant difference between the two eyepieces. The panoptic gives you 2.4+ degrees true field, the Nagler 2.6. That's a broad field for all but a couple of objects under very dark skies. The exit pupil is not an issue in either case. They're both pretty heavy as in rebalancing.

I would stick with what you have.

September 14, 2006 09:48 PM Forum: Eyepieces

Zeiss Abbe orthos 1,25"

Posted By Lorne Johnson
There was a fairly careful review done on Cloudy Nights of the Supemonos, Pentax SMC's, UO's and ZAO's. I believe that it was by Albert Beq. That review found the ZAO's and Supemonos to be be very close in image quality at 10 mm with the Super Mono's gaining a subtle, but increasing advantage at the shorter focal lengths. That review placed the ZAO's slightly ahead of the Pentax SMC's. The UO's are still the best buy.

It would be worth your time looking for the review.

November 5, 2006 05:09 PM Forum: Equipment Talk

Telrad or Laser

Posted By Lorne Johnson
john shea said:

Which would be better to use, Telrad or one of those lasers attached to the scope which throws the beam into the sky when aligning the scope to an object. Seems to me the laser would be easier.

The short answer to your question is the Telrad. However, some folks, like myself prefer the Rigel "Quick Finder" which is essentially a Telrad-type finder in a smaller, easier-to-use package with most Telrad options included as standard. It is especially handy on smaller scopes.

January 18, 2007 04:44 PM Forum: Equipment Talk

Intes MN 65 Mak-Newt (long post)

Posted By Lorne Johnson
Hi John!

I have an MN 56, and so may have some useful info.

1. The tube on the scope is not round, so the third ring for rotating isn't that great a fix. Parallax makes rotating rings for that scop--about $350 I believe.

2. The Scope is great on the Unistar Heavy alt az mount.

3. Astrozap makes a great dewshield for it (that stores around the OTA in the nylon case and balances better than the heavy Intes version).

4. The focuser is definitely the worst part, but the mounting plate can be drilled for JMI or Starlight Instr. Moonlight has a fix as well, but it uses the Intes set screws, and I am leary of that. Currently deciding whether to use the single speed crayford from my dob on it or upgrade both scopes to Feathertouch (probably the former).

The optical views are very impressive indeed.

January 24, 2007 03:21 PM Forum: Beginning Astronomy?

What's the difference between long and short focal

Posted By Lorne Johnson
Kevin Morin said:

Hi,

I'm in the process of looking for a first scope and have a choice between a mak-cas or a mak-newt. Nothing too big, not too much maintenance, and something that has excellent quality. Both Intes scopes I've looked at offer great views but I've read a few articles about some people wanting longer focal lengths but they don't state why? What is the difference between a F6 mak-newt and an F10 mak-cas? Does the focal length affect what you see? I hope this isn't a obvious or stupid question but I get so caught up in trying to analyze every detail to make sure I pick the right scope.

Wider field of very is also good for finding objects (if you don't use go-to). It can be pretty frustrating for beginners to look for almost anything that isn't a planet or the moon.

January 26, 2007 07:43 PM Forum: Equipment Talk

ED Barlow

Posted By Lorne Johnson
Dale Smith said:

If I add a ED Barlow to my achromat refractor will it remove the blue halo? Dale

No, as noted. There is an optical devise called a Chromacor that will do a pretty good job of what you want (can alos be ordered to help over or under correction of the achromat lens). Never used one, and they are pretty expensive, but created a good buzz here a few years back.

January 26, 2007 07:48 PM Forum: Eyepieces

University Optics 32mm MK80

Posted By Lorne Johnson
I find the Siebert 34 or 36 observatory grade to do very well indeed. New $200 not cheap, but on the few occasions that they show up for sale $150 seems to be the asking price. I picked up a spare on the Auction for even less (to my surprise).


robert cosgrove said:

Hi all,

I'm tempted to pick up this eyepiece. I've enjoyed every UO eyepiece i've ever laid hands on. My problem is this...i'd like to use this eyepiece in my new 8" SCT, but would also use it as a finder eyepiece in my dobsonian. Does anyone have experience with this eyepiece in a dob?

I'm assuming it will be excellent on axis, but be filled with coma in the outside 20%? That would be OK with me since this is not a Nagler. lol

Another alternative is to be patient and wait for the Paragon 30mm to show up......waddaya think?

Any info or suggestions would be great. I do NOT have the money for Televue, Tak or Pentax-though I wish I did. :-)

Rob C


February 8, 2007 02:18 AM Forum: Eyepieces

Siebert Ultra's...which ones?

Posted By Lorne Johnson
I'd ask Harry, he's been very honest with me. The 24 mm "high transmission" would be dynamite in the sCT, but not so great in the dob. The 22 mm should be very good in both.

I

robert cosgrove said:

Hi there!

I have two opposing scopes...8" f/10 SCT and 10" f/4.9

I just received my 34mm Siebert Observatory-for the second time(I regretting selling it in the past).

Now i'm wondering which Ultra's are your favorites that might be a good compromise between the two scopes? smile


m thinking somewhere between the 22mm and 9mm range. I have the money to purchase two more. Maybe one at the higher and one at the lower range?

Thanks!

Rob

February 14, 2007 09:23 PM Forum: Reflectors

T-scope or Portaball

Posted By Lorne Johnson
Scott Anderson said:

Just another quick question:

What's your thoughts, 14" t-scope or 8" portaball?

The T Scope is clearly a beautifully engineered scope. I would be interested in hearing from people who have successfully taken delivery of one.

March 1, 2007 10:23 PM Forum: Eyepieces

How do you hold your EPs between use at night?

Posted By Lorne Johnson
My overall settup is considerably cruder than yours. It's either the refractor on a tripod mount or the dobsonian, and my chair an old LL Bean hunting stool. My main eyepiece case is a $4.00 six-pack cooler from walmart with a plywood insert with 1.25 and 2 inch holes much like an eyepiece tray (loosely based on one that was written up on cloudy nights). It has a white top and orange handle (and presumably changes temperature very slowly with the lid down). I usually oberve alone, and just set the cooler on the ground next to the stool. I really like the cover, which cuts down on dust and acts as a dew shield, but opens quickly for switching to other eyepieces.

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