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Posts Made By: Philip Canard

March 11, 2009 04:51 AM Forum: Equipment Talk

Aligning Celes ASGT

Posted By Philip Canard

Did you do the daylight savings time entry correctly? It will throw you off 15 degrees.

Is it set for Northern Hemisphere or Southern Hemisphere?

Did you do a reset and return to factory defaults before proceeding?

March 12, 2009 01:17 AM Forum: Audio

MP3 format becoming preferred by our youth?

Posted By Philip Canard

I'm still listening to Frank Sinatra records on an old VPI turntable I bought 18 years ago......and it's amplified through a vacuum tube phono stage......with tubes that were made in the 50's and 60's.

Phil


March 12, 2009 06:32 AM Forum: Birding Optics and Photos

Looking for spotting scope recommendations

Posted By Philip Canard

Baader makes an 8mm to 24mm zoom eyepiece that can be used on most Celestron spotting scopes as well as at least one other....Zeiss or Pentax. It's probably Zeiss spotting scopes as Baader is the "new Zeiss" as far as astronomy products go.

Alpine Astronomical and Astro Physics are Baader dealers in the USA.

Phil

March 12, 2009 07:49 AM Forum: Refractors

Tv barlow or powermate in 120ed eon refractor

Posted By Philip Canard

Barlows do not work well with long focal length EP's. They are much worse at blacking them out and move the eye relief back....something you do not want witha 25mm Plossl.

My rule of thumb is to stop using a Barlow at around 15mm with a Plossl. A Powermate will work better from there and longer in FL beacause it does not move the eye relief back, does not cause blackouts, and collimates the light path for maximum light throughput.

With a Plossl shorter than 15mm, you want to increase the eye relief, and a Barlow will do that. At the narrow field stop diameters of short FL EP's, the diverging rays of a Barlow will still be fairly parallel and will not cause optical problems. A Barlow can have higher contrast because it has half as many optical elements as a Powermate.

Barlows are for short FL EP's, and a Powermate is for any FL EP, but best with a moderate to long FL EP.

A Powermate is also a good OCA for a binoviewer, so you can kill two birds with one stone and justify the increased cost relative to most Barlows.

Phil

March 12, 2009 07:59 AM Forum: Ask rating questions here

Rating an auction buyer who doesn't pay

Posted By Philip Canard

Yes, it's possible.

How badly do you want this guy "rated", and what are you willing to pay?

March 13, 2009 05:03 AM Forum: CCD Imaging and Processing/Deep Sky

Which Astrograph?

Posted By Philip Canard

Floyd,

Why not just buy a cheap Meade SN-8 OTA for now and be done with it? You can always start taking photos and get experience that leads you toward your dream scope....without bankrupting yourself. Yes, the focuser is crap and so is the finder scope, but those are fixed rather cheaply. The JMI NGF55 Crayford focuser is made just for that scope, and it works very well. Mine handles lots of weight with no problem. The scope rings are ready to mount a guide scope.

The SN-8 is no deadbeat when it comes to deep sky viewing, either. On a warm midsummer night when the seeing was exceptional, I saw the central star in the Ring Nebula. That was before I even knew there was a central star in the Ring Nebula, as I was a newbie to astronomy.

The collimation is pretty lousy from the factory, and you are going to have to properly align it and buy a heater strap and a dew shield and replace some crappy weak bolts. My brother said that the brightness of my SN-8 was as good as his Orion 10" Newtonian.

The f/4 speed of the SN-8 will do you a lot better than the f/6 and f/8 speeds of the scopes you are considering. f/4 gives you an exposure time less than 1/2 what an f/6 scope does, and f/4 is 4 times faster than f/8.

The Baader MPCC is very economical and will get rid of any residual coma of the f/4 mirror in the SN-8. There are online users of the SN-8 + Baader MPCC with photos posted to prove the point. Good is good, even if it doesn't cost much. Weasner has a good tutorial on his website for collimating the SN-8. I did mine a bit differently, but his way is certainly very good. The SN-8 (and also the SN-6 and SN-10) is very popular and there will be lots of information and accessories in the future to wring every lasy bit of performance out of it. The OTA is cheap enough that you can afford to tweak it without risking serious financial loss if you screw up now and then.

It's about as compact a Newtonian as you will ever see as well. JMI also makes a special case for the SN-8 and SN-10 OTA's. I have one and it makes transport very easy. Also buy the JMI NGF55 or FeatherTouch focuser and you are in business. Cost will be somewhere in the $1000 range, + or - depending if you buy new or used.

Phil

March 23, 2009 07:40 AM Forum: Eyepieces

Best Eyepieces for a Celestron Comet Catcher

Posted By Philip Canard

The best EP at a very cheap price in a fast scope is a Plossl.

I find that in fast scopes, just use a Powermate to get the focal ratio to f/8 or longer, then use whatever eyepieces you want to use.

A 1.25" 2.5X Powermate would be ideal for the Comet Catcher.

April 19, 2009 12:51 AM Forum: LUNATICS

Moon Filter

Posted By Philip Canard

I use a binoviewer, which cuts down brightness by a little over half due to the light split, and I use enough magnification to reduce the exit pupil to below 1mm. An exit pupil of about 0.5mm is ideal with a high quality refractor or Mak scope when binoviewing the moon. Planets need a bit larger exit pupil due to their lower brightness. If I ever use a filter, I forget about the moon filter and use a red or orange filter, or you can use a different filter in front of each EP, such as a red and blue, for a more 3D image. My preferred scope is a 150mm LOMO Mak-Cass and a mag of about 250X on a normal night with average seeing conditions. That's an exit pupil of 0.6mm and there is no need for a moon filter. The binoviewer greatly reduces floaters that are problematic with small exit pupils.