Star*Sweepers & Multipliers
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Denkmeier Optical Fully Multi-Coated Lenses|
Pictured are the 2" versions of The Star*Sweeper and The
Multiplier. What do they do? These optical components serve a variety
of functions. They are available in 1.25" and 2" formats so that they
may be threaded onto either size star diagonal or devices that accept
1.25" or 48mm (2") male threads.
With Refractors: Basically, the
Multiplier acts as a Barlow. The difference is that the Multiplier is
modular and will thread to any existing accessory that can accept
male 2" threads or male 1.25" threads such as star diagonals with
filter threads on the telescope-side tube. This optical
cell may be threaded into the telescope-side filter threads of a star
diagonal to create around a 3.5X magnification factor when used with a Denkmeier Binoviewer
in a refractor. Be aware that out-travel will be required and an
extension tube may be necessary for refractors with limited focus
travel (less than 3.5" overall mechanical travel of focuser tube). If
needed, the extension is placed in the telescope focuser first (before
diagonal). Most refractors will not reach focus with our Multiplier
threaded directly into the nosepiece of a Denkmeier Binoviewer.
The Multiplier will operate for single eyepiece usageand
less out-travel of a refractor focuser tube is required. It may be used
for approximately a 2X
magnification effect when used on the eyepiece side of the star
diagonal. Any 2" Extension tube that accepts male 48mm threads can then
be used as a "Barlow" when the Multiplier is threaded in and an
eyepiece is slipped into the extension tube. Simply put, the greater
the distance between the eyepieces (used in a binoviewer or singley)
and the Multiplier Cell, the higher the magnification factor will be.
The eyepiece/Multiplier distance is greater when a binoviewer is used
so the magnification factor of The Multiplier is greater in that
capacity than when a
single eyepiece is used. Some star diagonals (like our Denkmeier 2"
Diagonals) allow the Multiplier to be threaded in closer to the mirror
on the telescope-side and magnification is slightly lower and
out-travel of focuser tube is also less than if the Multiplier is
threaded to the end of the diagonal tube on telescope-side. So, it is
also true that the closer the Multiplier is to the eyepiece, the less
mechanical out-travel is required to reach focus. This Multiplier may
threaded to a 2"/1.25" adapter that has female 48mm filter threads.
This places the Multiplier closer to a single eyepiece. The Multiplier
will also work for photography and will increase image scale in greater
amounts as spacing between Multiplier and camera is increased. The
Multiplier threads to any camera adapter with femal 48mm threads.
With SCTs/Maks: These
telescopes have large image scale capability without using barlows but
if very high magnification is desired or fairly high magnification is
desired with low power eyepieces, the Multiplier will provide this. Use
in a 1.25"/2" adapter with 48mm female threads, or use in your star
diagonal telescope-side tube if it has 1.25" or 2" filter threads. Be
aware that magnification is quite high iof used in a star diagonal on
the telescope-side tube that has filter threads. This will be in excess
With Newtonians: The Multiplier
is a great tool to have when a Denkmeier Binoviewer System is being
used. By replacing the normal OCS cell with the Multiplier (available
for the 1.25" or 2" OCS Systems), approximately a 3.2X magnification occurs
when the Power x Switch Arms are in the "OUT" position and only the
Multiplier Lens is in the light path. The Power x Switch magnifications
are also boosted by about 30% when the Multiplier is used instead of
the OCS Optical Cell that comes with all Power x Switch Packages. This
means that a single pair of D21 Eyepieces work at even more
magnifications. So, when a very steady night is the case, thread on the
Multiplier in place of the OCS Cell and get that extra boost in image
scale when you want it.
The Multiplier can even be threaded directly into any 2" eyepiece that
has 49mm (2") filter threads. The multiplication factor will be reduced
to some degree due to close proximity of the Multiplier to the eyepiece
and this depends on some of the mechanical apsects of the eyepiece.
expect a factor of approximately 1.5X +/-.
Note: The Multiplier is different than the "2X Multiplier" in that is
provides higher magnification when used in all telescopes. The 2X
Multiplier was included as a thread-on multiplier for SCTs and when
used on a Denkmeier nosepiece provides a true 2X magnification. The
Multiplier provides 3X when used in this manner and higher powers when
used in star diagonal filter threads. The 2X Multiplier is still
available for $149 and may be added to your Shopping Cart by choosing
it in the drop-down.
The SCT Richfield Star*Sweeper"
Note: The 2" SCT Star*Sweeper is the
cell used in the Cloudy Nights article featuring the Collins I3 image
intensifying eyepiece. The price is $149 + Shipping.
This is the original Patent Pending Denkmeier SCT Richfield
Star*Sweeper that changed the way that binoviewers are used on SCT
telescopes and many Maksutovs as well. These reducers cannot be used
with Newtonians or Refractors because back focus is limited. However,
SCTs can utilize these optical cells to reduce normal magnification and
obtain wider fields of view. This is very important when viewing
certain objects like large star clusters, nebulae and galaxies. The
light from these objects is compacted into smaller areas and therefore,
brightness per square arc second is increased making them much easier
to see. These 1.25" or 2" Star*Sweepers thrad to any Denkmeier Binoviewer
nosepiece allowing focal reduction to occur with most SCTs and many
Maks. When using single eyepiece, If you have a different brand of
binoviewer, this cell can be threaded to a 2"/1.25" adapter that has
such filter threads and focus may be possible allowing reduction. While
we design these to allow focus on Denkmeier Binoviewers, some other
binoviewers may also reach focus though we do not provide specific tech
advise for other brands. Be aware that Denkmeier prisms are 26mm clear
aperture and when using eyepieces and the Star*Sweeper, binoviewers
with smaller prisms will likely vignette or "darken" at the field edges.
Never thread a focal reducer into your SCT Visual Back again. These
Star*Sweepers thread into the telescope-side of slip-in type star
diagonals and allow focal reduction of approximately F/6 to occur.
While our Power x Switch Star diagonals accomplish this without the
need the ever thread anything in or out, these Star*Sweeper cells are
the next best thing and will integrate with any 1.25" or 2" star
diagonal that have the necessary filter threads on the telescope-side.
The 2" version Star *Sweeper cells can be threaded into a camera
adapter as well for photographic use provided that the adapter has 48mm
female threads. The greater the distance form the eyepieces or camera,
the more extreme the focal reduction factor will be.