Image of the day

From the
ATWB Customer Gallery

NGC2264 - Fox Fur Nebula

My Account

New to Astromart?

Register an account...

Need Help?

Intes MN 65 Mak-Newt (long post)

Started by mirfak, 01/17/2007 10:47PM
Posted 01/17/2007 10:47PM | Edited 01/19/2007 08:19PM Opening Post
[COLOR="Red"]Correction: this scope is the MN 65 [/COLOR]

I have spent years looking at the ITE website with its exotic Russian
Mak-Cass and Mak-Newt scopes.

http://www.iteastronomy.com/products/telescopes/index.php?tid=50

I have never seen one in person and dont know anyone who owns one. I
decided to try it. The MN65 is a Maksutov-Newtonian, basically a
Newtonian with a corrector plate that holds the secondary.


I ordered a the MN65 on a Monday and it arrived on a Wed. (!!!)
The scope comes with a nice black nylon padded carry case with some
room for accessories. Grade: A

Everything on the scope is metal, even the focuser plug. There are two
finder brackets on either side of the focuser. A small camera mount
fits into either finder base. The rear of the scope has a removable
plate to allow air circulation. The primary mirror is center marked.
The scope rings/cradle is thin and flat, with felt inside. One large
center knob tightens the rings. Inside tube is well baffled. Grade: A

The Crayford focuser has an inside diameter of 2-3/16 inches or 55mm.
Inside this is a removeable 2" drawtube that holds a 1.25" drawtube.
The focuser barrel never intrudes on the light path. The two drawtubes
are clumsy and aggravating to extend to the proper length, especially
when non-parfocal oculars are used. On the plus side all the adapters
are compression-ring, not set-screw. The in-out motion is smooth. This
is the least user-friendly focuser I've ever seen. (Im used to the JMI DX crayford). Grade: D minus

The finder scope contains the only plastic parts, the eyepiece cap and
the tips of the holding screws.(A nice touch) Its a 50mm straight-thru
finder with etched crosshairs. Optically its very sharp, but the
crosshairs are invisible at night. The body is thick metal, also the
objective cap. The eyepiece rotates to focus. The entire thing is heavy
like a 4-D cell Maglite. Mechanically and optically sound but poor
functionality. Grade: C

Field test. Wed night was the first good clear night in two weeks. Very
cold and dry. Transparent but turbulent skies. The Zodiacal light was
brighter than the Milky Way and extended almost to the meridian. I
allowed the scope to cool for 30 minutes before using. Eyepieces: TV Plossls and various orthoscopics.

Optically the views are stunning. STUNNING! With a 32mm plossl ep the
entire Orions's sword was visible. With a 20mm plossl 4 trapezium stars
were seen. Detail was visible in the nebulosity, the stars focused to
nice round points against a black background. There is still some coma
or field curvature seen at the very edges for the fov, but you have to
look for it (18mm Ortho). Very minimal, say the outer 3% of the fov.
With a 6mm Orthoscopic, concentric rings were seen inside and outside
of focus. Im no optical expert but the star test looked good. Sirius at
150x was a blur(poor seeing + low altitude), but notably absent were spikes from spider vanes as
seen in a regular Newtonian. No false color noted on any bright stars.
Many faint field stars were seen. Back in Orion, NGC 2024 was spotted
next to Zeta Ori, with that luminary in the field. The last target was
M35. With a 20mm plossl it appeared as a bright sprinkling of stars,
one notably orange. Smaller and fainter NGC 2158 was easily seen and
distinct next to M35. Optical Grade: A++

My observing was very limited due to the cold. I was sweating under my
winter clothes, but my ep's sat in the cold car all day. The moisture from
my breath frose instantly on the eyelens of each ocular. Temperature
was in the low 20's.

Overall Impression: I have very mixed feelings about this scope. Its
wonderfull to look thru, but the focuser is a pain. When moving the
scope the eyepiece always seemed to be at an inconvenient location, due
to the equatorial mounting. This made the finder awkward to use also.
With an equatorially mounted refractor, its simple to rotate the
diagonal for eyepiece adjustment. This scope is optimal for imaging due
to its wide field, large focuser and mirror placement. Im a visual
observer only, these features dont help me much. Im not used to
fumbling with the focuser drawtube when changing ep's. I also dont like the corrector plate so exposed. I find myself almost grabbing the front lip of the scope like my old dob.

I'll give this scope a few more nights before I decide if the optics
outweigh the awkward functionality. You may see this scope in the classifieds soon. Im terribly used to alt-az scopes. This is my first non-refractor on an Eq mount.

Clear Skies,
John R


Attached Image:

mirfak's attachment for post 35378
Posted 01/18/2007 04:55AM #1
>>>Overall Impression: I have very mixed feelings about this scope. Its
wonderfull to look thru, but the focuser is a pain. When moving the
scope the eyepiece always seemed to be at an inconvenient location, due
to the equatorial mounting. This made the finder awkward to use also.
-----

Hi John:

Nice reading about your new scope. Sounds like it is very nice optically. Here are a few comments from an Newt Nut...

The focuser position is a issue with any equatorially mounted scope, With a Newtonian the proper position requires rotating the OTA. The normal procedure is to rotate the tube in the rings so the focuser is in the best position. This takes a moment or two so there are a couple of solutions to this.

1. The preferred solution is "rotating rings." These are rings with bearings that allow the user to easily rotate the tube. Parallax makes these and but they are around $400 from what I understand.

2. A simpler solution is to use a third tube ring above the top ring. Then you leave the other two slightly loose and the third ring keeps the OTA from sliding down. These are essentially "poor man's tube rings."

3. The hard way, you just loosen and tighten rings each time you want to reposition the focuser. It is easist to do this with the tube horizonal so it doesn't slip in the rings.

Which ever you choose, it is an important step in compfortably viewing with a GEM mounted Newtonian.

It is interesting to see that there are two finder mounts, one on either side of the focuser. I have often considered doing this because it makes the scope much easier to use.

With a Newtonian it is a big help if you can be on the side away from the counter-weight rather that straddling the counter weight or otherwise dealing with it. One can always rotate the tube into a position where the eyepiece is comfortable but this can mean that the finder is now below the focuser so that it is difficult to use.

But with the two finder mounts, this problem is resolved and you can be on the correct side of the mount at all times.

Anyway, I am sure you will soon be accustommed to viewing with a your beautiful new scope and you will come to enjoy having the focuser on the sky end of the scope...

Best wishes and clear skies...

Jon

Posted 01/18/2007 06:17AM #2
John, if you keep the scope, you might want to use it on the Unistar Heavy mount from Universal Astronomics. Rock solid on a Heavy Surveyor tripod. I'm not an EQ user myself.

Great report and good luck!
Posted 01/18/2007 08:19AM #3
Great report, literate, intelligent, perceptive.
I would mount the scope on a WO Easy Touch if it will handle the weight (ask WO) or on a Giro 2, or best of all, on a Disc Mount 4. Use the equatorial only for imaging, not for visual.
Good luck,
Bill Meyers
Posted 01/18/2007 08:44AM #4
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.
Posted 01/19/2007 10:59AM #5
Hello John, enjoyed reading your report on the MN56, they're not mentioned too often, but for sure they're one of the really good Maksutovs out there.
Everyone else has said it all I would suppose, but I would add that the Intes extended front baffle tube is a good piece of work. Unlike their version of the Crayford which tempers the joy to be had with this 'scope: it's dire. I like the multiple draw tubes which would probably accomodate most eyepieces, but that's about it.
I post this because only a very few weeks ago I spent a couple of hours on the lathe to knock up an adaptor ring so I could marry a FeatherTouch to the MN. Yes, I used the tiny two Intes set screws ( almost like 'speck screws' ) to hold the adaptor onto the tube plate's base and, as can be seen, three overlong Allen headed set screws-they were to hand- through the adaptor to hold the FT. Loosening one of the screws still allows the focuser to swivel to wherever's handy. I didn't have the FT reducer ( 1.25") so I borrowed the Intes tube as in the photo.
It's transformed the 'scope. smile

Bruce


Attached Image:

Bruce Mills's attachment for post 110908
Posted 01/20/2007 02:18AM | Edited 01/20/2007 02:28AM #6
John-
I picked up a used MN-56 last year and my first experiences mirrored yours.

A Rigel finder makes a decent alternative to the IM finderscope. The Rigel base attaches to the scope in place of either stock finder bracket base and the Rigel's viewing window a few inches above the OTA may be bit more comfortable to use than a Telrad might be.

My scope arrived with a single speed Moonlite focuser that I upgraded to a dual speed version. Very nice.

I added an IM baffled aluminum dewshield (not in photo). I find it's
effective and also guards against me inadvertently touching the corrector plate.

The scope rides on a Tak Modified Teegul mount on Berlebach tripod and I find it a very nice match. Of course, your MN65 is a bit heavier than my MN-56.

I'm continually impressed with how well these scopes perform, especially considerng their cost.

Good luck!

Charlie

Attached Image:

ryderc1's attachment for post 110922