microscope bino head

Adapting a Microscope Bino head for an astro telescope!

I just tried my eBay, Nikon Microscope bino head on my 3-1/2" Questar.
To my amazement it worked. I didn't think I could get enough back focus but
that was no problem. It does unbalance the Questar because of the added
weight hanging on the back. So far, I have only used it during the day.
Need to get some "clear" dark nights to do some better testing. Only
problem I can see so far is that you cannot swing it through the fork. A
friend of mine, John Purdy, is a model engineer with a small Myford ML7
lathe, and he made the adaptor so it will fit a standard 1-1/4" eyepiece
holder. One could also do it on a Unimat hobby lathe! Good quality wide
field microscope oculars seem to work just fine. I've got another set of
Periplan flat field oculars on the way. When testing is done we will
evaluate our results and perhaps do an article for the Journal of the RASC.
"A bino head on the Cheap"

Cheers:

Ed Majden & John Purdy
Courtenay/Comox
B.C.

There goes the days of the Denkmeier $599 standard! Way to go! Ever think of
opening your own business?

Adapting a Microscope Bino head for an astro telescope!

I just tried my eBay, Nikon Microscope bino head on my 3-1/2" Questar.
To my amazement it worked. I didn't think I could get enough back focus but
that was no problem. It does unbalance the Questar because of the added
weight hanging on the back. So far, I have only used it during the day.
Need to get some "clear" dark nights to do some better testing. Only
problem I can see so far is that you cannot swing it through the fork. A
friend of mine, John Purdy, is a model engineer with a small Myford ML7
lathe, and he made the adaptor so it will fit a standard 1-1/4" eyepiece
holder. One could also do it on a Unimat hobby lathe! Good quality wide
field microscope oculars seem to work just fine. I've got another set of
Periplan flat field oculars on the way. When testing is done we will
evaluate our results and perhaps do an article for the Journal of the RASC.
"A bino head on the Cheap"

Cheers:

Ed Majden & John Purdy
Courtenay/Comox
B.C.

"Jim"
There goes the days of the Denkmeier $599 standard! Way to go! Ever think
of
opening your own business?

This thing still uses 23 mm diameter microscope eyepieces. I will be
testing various types to see which works best, WF, periplan etc. The
Astronomical models use standard 1-1/4" eyepieces and probably have a larger
beam splitter and entrance aperture. I don't know. On axis I think both
would be comparable if you use WF type eyepieces which are colour corrected
Kellner types. As for starting a business, I've already got a headache and
don't need another one. ;-) I like retirement!
Ed

There goes the days of the Denkmeier $599 standard!

Hi:

Nah, prob'ly not. Decent used microscope heads are not always available for low
prices. And even if they are, most suffer from rather restrictive fields due to
small prisms. And wouldn't you really rather use good 1.25" "astronomy"
eyepieces, too?
Microscope heads can do an _OK_ job on the Moon planets, but for the deep sky
(or even for Solar System use) the Denk just blows them away. Frankly, for me,
the Denkmeiers made binoviewing a way of life rather than just a
curiousity--I'm serious.



Peace,
Rod Mollise
Author of _Choosing and Using a Schmidt Cassegrain Telescope_
Like SCTs and MCTs?
Check-out sct-user, the mailing list for CAT fanciers!
Goto http://members.aol.com/RMOLLISE/index.html

I used to have in my possession a modified Nikon binovewer - it was okay,
but it introduced cromatic abberation at high powers on planets (kind
of annoying). I don't think anything will replace hand craft binoviewers
quite yet. That's not to say that binoviewers couldn't be made cheaply
(they can), but you have to use the right components and get everything
square or colliminatable.

"Rod Mollise"
Microscope heads can do an _OK_ job on the Moon planets, but for the deep
sky
(or even for Solar System use) the Denk just blows them away. Frankly, for
me,
the Denkmeiers made binoviewing a way of life rather than just a
curiousity--I'm serious.

I agree with Rod. The light is split between both oculars so it is
quite a bit dimmer. Probably at least a 50% loss of light going to each
ocular. This is fine for the bright planets, moon, and the sun. To be
effective for deep sky, your going to need a large light bucket. I haven't
been able to compare it to a commercial unit so I can't comment on the
differences. I don't think it would work well on a short F-ratio instrument
because of the small entrance aperture but on a Schmidt Cass or Refractor it
works as expected. If you a deep sky NUT why not make a real bino telescope
with say, two 25 inch mirrors. That should work just great I would think!
;-)
Ed

Posted to the RASC members newsgroup and forwared to sci.astro.amateur.

I have read Alan Dyer's review, "Binocular Viewers for Telescopes", in
the September 2002 issue of Sky& Telescope, p.46-p.51. Will a modified
microscope head perform as well as the ones tested, not very likely. Alan
tested the Baader and Tel Vue heads at U.S. list prices of $1400 (more with
accessories) and $1050 for the Tel View. My modified Nikon head cost
approximately $50 U.S. on eBay.
Preliminary tests show that it does work. I have so far only tried it
on terrestrial objects and the Sun with 1.0" off-axis solar filter on my
Questar 3-1/2". To get enough back focus on the Questar, it is far from the
optimum design position of best viewing. There is 50% plus loss of light,
as the light is split in two, by the beam splitter and prisms in the unit.
The view is still acceptable. Another problem, especially for me. (For the
people that know me they are aware that my neck is fused and I have very
limited movement). The microscope head inclined from vertical by
approximately 30 degrees. When mounted on the back of a SCT or Questar,
viewing is fine near the horizon, but at high or near zenith observation
positions viewing is very awkward even if you can contort yourself into the
correct position, I can't, RATS! I still have to test the unit on the
planets etc. I doubt that it will work well for deep sky objects. Unless
you can afford one of the Rolls Royce viewers noted above you will have to
accept these limitations. Still a fun project.

Ed Majden
Courtenay, B.C.