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Posts Made By: Larry Thaxton

April 29, 2008 02:36 PM Forum: Equipment Talk

refractor choice?

Posted By Larry Thaxton

Hi Glenn,

I have owned many APOs including two of the Meade ED APO series, a 127mm and a 178mm. Both were excellent performers once collimated and centered. The 127mm never presented any issues, the 178 had a trip or two to Meade before it was right but once it was it was super! If you go with a Meade 127MM ED APO make sure it has the newer lens cell that allows centering the rear element. Here is a note from a few years back when I had the 127mm and a wonderful MN76:

26 December 2002

Cold and clear (for this area) night with a seemingly steady atmosphere. Took the 5" Meade APO and 7" MN76 out and placed them into the van for an hours cool-down. By the time I was ready to set them up, the sky had become unusually steady.

My first target was Saturn. Given the nearly identical focal lengths ( the Meade at 45" v the MN at 42") I decided to start with 7mm Pentax SMC orthos (lucky to have a pair on hand!). The Meade was turning in a rock solid, highly detailed image. Four moons were clearly defined as was Cassinis all the way around the ring. The outer ring was distinctly darker than either the B ring or the Crepe ring. Saturn's globe was a pastel olivine green with a darker band half way between the ring and the pole. From the band up to the pole the color darkened quite a bit. The pole and Cassinis were touching leading to a "hat-like" effect. The Crepe ring was quite obvious against the globe. Contrast was very good with the sky nearly black behind the image of Saturn. Being able to view from a seated position was a treat and made for a comfortable session.

Turning to the MN76 there was a pronounced increase in image brightness. Saturn was sharply defined and if anything, Cassinis was even darker and clearer-especially in the very front of the ring- than it had been in the Meade. The image was inverted relative to the Meade which made direct comparisons a bit tough. The moons were brighter as was the globe. All of the features mentioned in the Meade were seen easier in the MN76. Not sharper, the Meade held a steadier and possibly sharper image but the MN was just a world brighter which made everything easier to see. There was a bit of fluctuation in image sharpness- the image would go in and out of being razor sharp. This was not notices nearly as much in the Meade. Color more pleasing in the Meade, richer. The MN seems to overwhelm with light.

Switching to the 4mm Brandon-an old version I picked up recently- pushed the power to about what the conditions could hold. The Meade (285x) presented a good image but was starting to dim. The MN76 (266x) was sharp as a tack and I was able to glimpse-I think- Eckne's minima at least twice during moments of extremely calm seeing. I could not do this with the Meade. The 6mm Pentax SMC ortho was the best image in the Meade. Stunningly clear and detailed. The 4mm softened things up in the Meade more than in the MN76.

Jupiter was just coming into calm air around midnight. Back to the 7mm SMCs in both scopes. The Meade image was the best I have ever seen it turn in. Much like the evening Shoemaker-Levy hit Jupiter a few years back. Wonderfully detailed with the Great-Used-To-Be-Red Spot prominently displayed. Several bands present including two disjointed in the south equatorial region.

The MN was brighter but the Meade was better at showing low contrast features in the cloud bands. The background was a bit darker in the Meade as well. Again, things were easier to see in the MN due to the advantage in light gathering but the APO (really semi-APO as there was a bit of color showing) had higher contrast in the image.

Turning to 6mm eyepieces I tried the SMC v UO orthos. In both scopes the SMC was brighter then the UO and gave sharper and clearer planetary detail. The UO was excellent, the SMC better yet. Sharpness was a push in both scopes when using the same eyepiece.

Next I tried M42 paying particular attention to the Trapezium. Using the 6mm SMC ortho the APO pulled all six stars pretty easily. Interestingly, switching to the UO 6mm made it harder to see the two faint stars and I found I was using averted vision in it but not in the SMC. The MN with the 6mm SMC was brighter and all six stars were easy whether the UO or SMC was in the focuser. The APO surrounded the brighter stars with crisp diffraction rings. The MN was just about there but not as good as the APO. The star images were "tighter" in the APO but it was a small difference.


I know these are different enough that the comparison was stacked in favor of the MN but I was curious to try it anyway. The Meade had just had the new lens cell installed and been cleaned and collimated . The contest was really close- it is a matter of personal preference given the MN's brighter images. The Meade is a more convenient scope to use, gives a bit more contrast and is ever-so-slightly sharper. Sitting is a major advantage in comfort. The MN suffers from a crappy focuser and the need to stand frequently-at least on the G-11. I could live happily with either...

All said and done, I would vote strongly in favor of an older Meade 127ED. Get a good one and it will last you a lifetime!

May 30, 2008 07:36 PM Forum: Astro-Physics

Was it my imagination or did anyone else see

Posted By Larry Thaxton

I saw it too and was curious to see if a collector would spring for the whole collection. Guess one did!

June 4, 2008 10:22 PM Forum: Guns and Hunting Optics

Here's My Handgun Choice, Yours . . .?

Posted By Larry Thaxton

Smith and Wesson Model 19 "Combat Magnum" or a Series 70 Colt .45- depends on my mood.

June 12, 2008 07:34 AM Forum: Reflectors

ProPlanet 8" and 10" scopes

Posted By Larry Thaxton

Hi Darian,

I noticed the brief description as well and have to say I am curious about the scopes. While I agree with Jon about aperture ruling, there are many ways to optimize a Newtonian for planetary viewing not the least of which is reducing the secondary size. Unfortunately, that normally means longer focal lengths. At the moment, I have two excellent 8" Scopes, an old Cave 8" F/8 and a Uti 8" F/6. The Cave has a 1.3" secondary (16% CO) and the Uti 1.83" (22% CO). Side by side on fine planetary detail the Cave has a slight edge which I chock up to the smaller CO as both have excellent mirrors. Having said that, the best visual view I have ever had of Mars in a reflecting telescope was through a 10" F/5 Portaball. In my experience, the Moon and planet come alive in 10" and larger scopes. A very experienced observer I know says that 12.5" is the "sweet spot" in planetary scopes and I have to agree: the 12.5" Portaball is stunning on planets and the Moon.

July 4, 2008 08:54 AM Forum: Astro Binoculars

finding owners of giant binoculars

Posted By Larry Thaxton

Sorry I am not closer so you could try the Vixen 125mm 25-75x binoscope I own. Beautiful wide field views of the sky in seeming 3-D. They are like two RFT 5" refractors and while there is color on the edge of the moon, seeing it appear round and like another world makes up for it nicely. A friend "made" me buy these several years ago and he was really right, they are one of my favorite ways of seeing the sky.

July 13, 2008 07:44 PM Forum: Equipment Talk

SCT for the high-power crowd?

Posted By Larry Thaxton

While I recognize this is not an "SCT", Bob Royce is making a limited number of 10" F/20 Dall-Kirkham reflectors specialized for lunar, planetary and doubles. I ordered one of the initial five prototypes and have to say it was a great decision. The scope, #3, is easy to set up, a snap to collimate in the daylight (can you say that about a cat?) and when the seeing is good it puts up stunning visual images. It is not inexpensive but for such a superbly crafted instrument with conical mirror, built in cooling fan, a two-speed Moonlight focuser, curved diffraction-free spider and 25% CO I would not expect it to be. Its 5000mm focal length lets simple eyepieces shine. When the better skies of Fall and Winter arrive, I plan to try the Zeiss 10mm monocentric. Best planetary eyepiece I have ever used and a fitting choice for Bob's scope!

August 6, 2008 06:02 AM Forum: Reflectors

High quality 'planetary' reflectors?

Posted By Larry Thaxton

Hi Darian,

Parallax Instruments makes several fine Newtonians in sizes from an 8" F/7.5 to a 16" F/6:

And Bob Royce is making a small number of planetary optimized Dall-Kirkham scopes in 10" (One of which I own) and now a 12.5" both F/20:

The Royce 10" F/20 is a planetary killer and the images superb. I prefer being able to remain seated while observing as it is more stable and relaxed enabling better attention to viewing. Bob's D-Ks allow that as well. I recently read that Discovery was brigibg out a planetary line with an 8" F/9 and a 10" F/7.5 if I recall.

In my mind a planetary reflector requires an 8" or larger mirror of excellent optical quality, longish focal length, small central obstruction, a spider that minimizes diffraction and an effective cooling system. It would not require a 2" focuser as, in my opinion, the best planetary eyepieces are 1.25" format and the smaller focuser would allow a smaller diagonal/less CO. Having said that, the Mak-Newt scopes, particularly the MN76 and larger are superb though the front corrector can be a problem w/r to dewing.

August 16, 2008 08:43 AM Forum: Equipment Talk

Japanese Scope Pictures

Posted By Larry Thaxton

Another, this one a 10" refractor. Catch the weight- over a ton!!

August 16, 2008 08:43 AM Forum: Equipment Talk

Japanese Scope Pictures

Posted By Larry Thaxton

How about a coude?

August 16, 2008 08:45 AM Forum: Equipment Talk

Japanese Scope Pictures

Posted By Larry Thaxton

Since the yen-dollar rate is pretty good maybe a little aperture is in order: