Posts Made By: Rob Mackie

I've used most of the widely available unit finders...Rigel, Telrad, Stellarvue and Starbeam. Here are my thoughts:

Starbeam: the coolest looking unit finder, most expensive, and probably most overrated. Dot is too large, though the window is is clear, which makes it easier to see dim stars.

Rigel: Excellent value, stands high off the OTA so dew is very seldom a problem (at least out here in N. Calif). 2 degree concentric aiming circles facilitate star-hopping. I've used it on both dobs and refractors. Small size makes it especially useful on refractors

Telrad: 4 degree concentric aiming circles make it great for star hopping. Big and dorky looking. Dew always a problem if there's any moisture in air. Most of big dob users seem to favor the Telrad. Wonderful views if you can keep it free of dew. Good value.

Stellarvue: small finder dot is nice. No concentric aiming circles as with Rigel and Telrad. Big aiming window, but the plastic through which you must look is tinted! This cuts down light transmission, not a good thing at night. Nevertheless, the SV represents good value.

Bottom Line: go with Telrad or Rigel if you're using a dob. Avoid the Starbeam. It's looks and construction quality do not make up for its high price and lack of concentric aiming circles.

Rob Mackie

Have you considered purchasing the Meade LXD-55 10" and using it? If's it's not of sufficient optical quality, have Swayze optical (or some other highly competent optician)refigure the Meade mirror. You'll likely wind up with excellent optics for far less than $2,000 more than the cost of the Meade rig.
Rob Mackie

It looks to be an OK deal. Note that there is a Telrad mount, but no telrad, so budget accordingly. Also, it comes with a 1.25" focuser, which precludes you from using 2" eyepieces. 2" eypieces will give you a much larger FOV. The improved spider and tube flocking are worthwhile additions.

Discovery's mirrors have a good reputation, and an 8" F/6 dob is an extremely versatile combination of aperture and focal length...easy to move, set up and collimate. This would be an excellent scope for either a beginner or more experience astronomer. Discovery sells the same scope new for $449 plus $50 shipping.

The seller is not willing to ship, so if you're nearby, check it out yourself. Whether you buy this scope or another, 8" F/6 is a good choice. You'll get a lot of quality seeing for a relatively small outlay.
Rob Mackie

I'v owned both the TMB 100/800 (CNC version)and a Tak FS 102. Both were superb optically. The TMB is a no compromise triplet design that qualifies as a piece of industrial art. It's heavy and you need to be aware that alt az mounts that work well with the Tak FS 102 like the TV Gibraltar will be overwhelmed by the CNC TMB. I used my TMB on a Giro 2 alt az and a GM8 GEM. The FS 102 will work just fine when paired with a lighter GEM like a Super Polaris.

The TMB rotating focuser is superb, and the ability to shorten the TMB OTA for use with a binoviewer is an outstanding feature that I didn't fully appreciate at the time because I hadn't yet started using a binoviewer. The TMB tube rings and finder holder are built to survive WW3. They're beautiful but very heavy.

At first glance the Tak FS 102 @ $1,895 for the OTA is a great deal. But be aware that TAK sells everything ala carte. You'll have to add a 2" visual back ($110), clamshell tube holder ($180), finder bracket and finder ($250?), case (?) etc. You can reduce these additional costs by making do with a Rigel and using Parallax tube rings. CNC TMB 100/800 scopes have sold recently on Astromart for as low as $2,200 and that included everything...aluminum suitcase, tube extensions, rings, finder bracket and finder. Fantastic deal IF the TMB's weight is not an issue for you. The TMB requires more mount than the Tak whether you use an Alt-Az or GEM.

As a quick look grab and go scope I preferred the Tak. It mated perfectly with the TV Gibraltar. Especially during the winter when I'm not able to get to my dark sky site with my 16" dob, I do a lot of planetary viewing from my suburban home. Quick, no hassle set up with a light rig really matters in these circumstances.

TMB now offers their 100/800 in a lighter OTA with Feathertouch focuser @ $2,595. This might be the way to go. You'll miss out on the "industrial art" aspect of the CNC tube, but you'll have a much lighter rig with fantastic optics, best focuser in the industry, and extension tubes to facilitate binoviewing. TMB also offers this setup for their 105/650 version.

I'm not one to split hairs over optics. All of these high end apos (Tak, TMB, AP, TV) have superb optics for visual use. Differences in construction approach, "look and feel", cost and availability have...for me at least...been the deciding factors in my choice of apo.

Rob Mackie

"i have the TV and now have a chance to purchase the Tak...should I?..."

In a word, No. These are both excellent 4" apos. Any difference through the eyepiece would be too minimal to warrant changing from one to the other. I use a binoviewer for planetary viewing through my 105mm Traveler, and this has greatly enhanced my planetary viewing experience, much more so than changing from AP to Tak to TMB etc etc.

For noticeably better images, you'll have to go up in aperture. The planetary views through my F/8 AP130 are better than any 4" apo I've looked through by a significant margin. So if you want better views, either get a larger apo ($$$) or consider a high quality 7" or 8" reflector.

Rob Mackie

Unlike SCT designs, there is no corrector plate on the Mewlon Dall Kirkham Cassegrain. This facilitates cooling and eliminates dew problems.
Rob Mackie

I have three reflectors, an 8" F/6, a Starmaster "shorty" 11" F/4.3 truss dob, and a 16" F/4.5 truss dob. All have excellent optics. If I had to choose one, I would go with the 11" Starmaster. It has great Zambuto optics, sets up quickly, and can be used seated at all times. The Shorty gives better planetary views than any scope I've ever owned, and 11" of aperture is enough to pull in most dso's.
Rob Mackie

Lukman,
The differences are NOT night and day. I did several side by side comparisons. The darker background of the mewlon and the brighter stars in the C9.25 are the giveaway. I've corresponded with others who've had both scopes. One observer said that the Celestron goes deeper into globular clusters (aperture advantage) but the M210 is more convenient because of lighter weight and no dew (lack of corrector plate). I use the M210 atop a GM-8. It's an excellent match. The C-9.25 also works on the GM-8, but the Celestron is at the limit of what the GM-8 can support.
Rob Mackie

Anthony,
I've used every type of scope. For quick look, back yard viewing, my 8" tube dob is the fastest to set up. It cools down fast and dew is never a problem. SCT's have cooling and dew problems, and of course require a GEM if I want tracking. The GEM always adds significant setup time, but of course yields more relaxed viewing once it's set up. My quick look viewing with the 8" reflector is generally self guided, no EQ table or motorized tracking.

A 4" apo is quicker to use than an SCT because it equilibrates very fast and dew is seldom a problem. Same issues for setting up the GEM however.

Assuming all scopes to be used alt az, unguided, here are my ratings of setup/quick use, from fastest to slowest:

1. 8" tube dob (just place the tube in base and start looking)

2. 4" apo

3. SCT

Rob Mackie

Ivan,
The Canon 15x50IS works as advertised. Optical quality is outstanding. The only negative I can think of is that for extended viewing of an object, these binocs start to get heavy. Even with good image stabilization (and Canon's is very good), you still have to support weight of the binocs. This is not a problem for quick looks. But studying an object for an extended period will put a strain on you arms. One solution is to use a reclining beach chair and rest your elbows on arms of chair...and let your head support weight of binocs. It's not elegant but it works. You can also simply lay on ground and achieve the same thing. A mount is nice, but of course this compromises portability.
Rob Mackie