Posts Made By: Gary Weber

About three years ago, I purchased a 1997 12.5 f/6 Starsplitter with a Nova Mirror. I think it is a very fine scope. I have looked through a ronchi test EP through a 2.5x powermate and can not detect a turned edge and the lines indicate a very good mirror (but I'm no expert there). It has always given me fine views. I downsized the 2.6" secondary to a Protostar 2.14" and replaced the secondary mount with a Protostar mount.

The Starsplitter I have is quite heavy. The mirror box, with mirror weighs about 65 pounds. However even at f/6, I can switch from a 22 Nagler to a 9 Ortho and the balance and movement remain solid and smooth. I have been able to track planets at over 500x using only a thumb and forefinger. I think the mass of the mount may contribute to the smooth movement.

All in all it is a fine scope and the price offered in the ad you mentioned is more than reasonable. I have been more than happy with mine.

Gary Weber

I am also looking at the Moonlight as a focuser. Does anyone know if it can be had with a curved base?

Gary Weber

I find this thread interesting as I mostly pay for Astromart purchases with a money order. It's perhaps a little different for me as I live in Canada and often I am dealing with a seller in the USA.

One thing has come clear to me...the postal system here is much more customer oriented and efficient than in the USA (They were told to become lean and mean and pay for themselves and they are hustling for customers and busisness - imagine that!).

However, I have a question for you folks in the USA...
Would you prefer to receive a money order from the post office, or a bank?

Gary Weber

I compared a Lumicon (from 2001) with a new Astronomik OIII in my 12.5 f/6 reflector on a couple of occasions. In skies with a LVM of ~5.8, I could detect no difference between them. Only in very transparent skies (LVM ~6.4) did the Lumicon show it had much better contrast on the veil nebula.

I was able to test both filters with a spectrometer and the bandwidth on the Astronomik was wider than the Lumicon and this showed less colouring of stars, was a little brighter and seemed to be more appropriate for smaller aperture scopes.

Here is a website that shows some results from spectral transmission tests with some different deep sky filters.
http://home.freeuk.com/m.gavin/grism2.htm

Gary Weber

You seem to be struck with a Mak, but with $3000, you have a number of options. one option is to look at two scopes.

Discovery 10" f/5.6 DHQ dob - $760 shipped
Celestron CG 5 GT EQ mount w/ goto - $760
Intes Micro MN56 Mak Newt - $800

The Discovery comes with a couple plossls. That still leaves you with over $500 to spend on a powermate and a couple eyepieces or other accessories.

You have 10 inches with good optics for deep sky (and suprisingly good planetary performance). You also have a 5" wide field that is great on planets (for its aperture) on a goto mount.

What more could you want?

Gary Weber

Here is what I did, and I have done it twice now (different scope the second time). It works well enough that I wouldn't change anything if I was to do it again.

I wrote this quite some time back. The links are too long to post. search for message #111638 & #111639.

Gary Weber

This is taken at our club's observatory, with the roof rolled off.
My 12.5 f/6 Starsplitter and a Stellarvue 102 f/6 EDT.

I believe the TFOV is ~ 3.3°. As for the weight, I cannot recall exactly, but I think it's around 3 pounds, perhaps a tad less. There is no focuser and the diagonal assembly is pretty small so it does make the scope pretty light for 80mm.

Gary Weber

[QUOTE]Ed York said:

For filter slides or a flip holder similar to the moonlite CR3/CR4 design, since these mount id, do they interfere with the view?

** I use an Astrocrumb filter slide on my 12.5" truss dob. The inside diameter of my UTA is about 13.75" and I can see a slight indentation in the "roundness" of my primary mirror when I am collimating. If I remove the slide, I notice no such indentation. I simply use the filter slide to make comparisons of filters or when I am wide field cruising with a few different filters. I used the slide a lot when I first installed it. I compared filters and selected the OIII that works best for me. I also placed both the UHC and the OIII in to find which worked best - I still do this but much less than before. I don't use the slide a lot anymore, but it's nice to have and it makes comparing filters a snap.

I have one filter that I generally use for Jupiter and Saturn. When planetary viewing, I remove the filter slide and mount the filter on my 1.25" adaptor.

How much obstruction does this add?

** Obviously some, but it is very little in my experience.

Do you notice any diffraction spikes?

** I have never noticed any diffraction pattern coming from the rails. When viewing planets, I have the slide removed.

I have a truss dob so the secondary cage is designed a bit tight. Does this make a difference?

** Sure, if the circumference is tight, the slide will intrude further into the light path. You'll have to determine if your circumstances are such that the slide is too much of a compromise. I am pretty sure that if I acquired another telescope, I would install a filter slide again.

Gary Weber

Floyd I own a Starsplitter dob. I bought it used from a local member about four years ago. It is a 12.5" f/6 truss scope and was built (I think) around 1997. Unfortunately, I have no experience with other commercially built scopes and cannot make comparative statements.

The mirror box is quite large. In fact it dwarfed a Discovery 12.5 f/5 that was nearby once. I have had people say they thought it was a 15" scope. The wood is quite thick, and with a large mirror box, it is very heavy. I am guessing that the mirror box with mirror weighs about 60-65 pounds. I keep the scope stored at our club's observatory and I am gald of that because I live on a third floor flat. I have carried that beast up the stairs twice...and that's enough.

There is a small hole (1/2") in the backside of the mirror box that has a metal insert with threads. The scope comes with a 5 pound (approx.) weight on a threaded shaft. You can thread this weight into the hole in the back of the mirror box if more weight is required from adding finders etc. on the upper cage. I have never used this, but I thought it was a pretty good idea.

However, I believe the mass of the scope contributes to truly wondrous movement and balance. As an f/6 it has long truss poles. I have no trouble changing from a 22mm Nagler to a 9mm ortho and the balance and movement never know the difference. On a few occasions I have had the power up over 500x while viewing planets. I can honestly say that at that power, the movement can be accomplished with a thumb and forefinger. The movement is very smooth and there is no backlash at all.

It sets up and takes down very easily and requires no tools. The large mirror box has allowed me to install a couple 90mm fans to blow across the mirror face and stay tucked out of the way. I have not encountered any feature or aspect of the scope where I have thought "I would not have that on my next scope", or "I want to change that". Again, I must say, I have not used any other commercial scope, so there may be better ways of doing things and I am just unaware of them.

Tom Trusock over on Cloudy Nights owns (or owned) a 15" and he may be able to make some additional comments. I believe that Phil Harrington (on Talking Telescopes) owns an 18 or a 20. There is not a lot of available information about this line of scopes. If I was up-sizing, I would not hesitate to acquire another scope from Starsplitter.

Gary Weber