PetersonEng - EyeOpener™ 2 inch Visual Back

For Meade LX-400, LX200-ACF, LX200GPS, LX-90 & LX200 Classic

An EyeOpener enhances the performance of long focal length 2" eyepieces on Meade 10", 12" and 14"
Schmidt-Cassegrain and Advanced Coma-Free telescopes by increasing the eyepiece optical path size as
much as 65%.  Get all of the eyepiece aperture that you paid for while enjoying the full benefit of 2"
eyepieces.

As Schmidt-Cassegrain Telescopes (SCTs) evolved from 8-inch models to larger-aperture scopes, and as
eyepieces evolved from 1.25" to 2", the "Schmidt-thread" couplings used for securing 1.25- inch
diagonals and eyepieces to telescope backplates remained unchanged. This "Schmidt visual back" supplied
with your LX400 or LX200 scope has an internal diameter of 1½", and it functions as a 1½ inch-diameter
field stop.  This field stop effectively limits the performance of your costly 2" optics to the
equivalent of 1½" optics.  When using the 1½" visual back with Meade's 2" 56mm Plossel (an eyepiece
with a full 2" of glass in the nose)  you loose 65% of the light to your eye! 

Do you think that the large diameter front lens (the "field lens") on your long focal length 2"
eyepiece is there for decorative purposes"  That's about what happens when you restrict the size of the
optical path to that lens with a 1½ inch-diameter field stop.  Without the EyeOpener® you're
getting the equivalent of 1½" optics.  You might as well take a piece of 1/4" wide masking tape and
cover up the outside 1/4" of glass on the nose of your eyepiece.

How does it mount"  The EyeOpener threads onto a 3-1/4" male thread found on the backplate of 10", 12"
and 14" Meade SCT & RC scopes, providing a full 2"  unrestricted optical path.  The microfocuser
attaches directly to the EyeOpener.  Unscrew your 1-1/2"visual back and check it out for yourself.  To
use the EyeOpener on  LX400 scopes and on the older "Classic" Meade SCTs, or to shorten the optical
path by eliminating the Microfocuser you will need the EyeOpener 2" Tube Adapter.  The EyeOpener will
also allow "Classic" SCT owners to retrofit a Meade #1209 Zero Image-Shift Microfocuser or JMI's NGF-S
electric focuser.

Microfocuser mounting thumbscrews now included.  Do you recall the old proverb about the added straw
that broke the camel's back"  Meade's LX400 and LX200 scopes are heavy enough to transport without the
added 1-1/4 pound weight of the Microfocuser.  Replace the 3 mounting set screws in your Microfocuser
with these special thumbscrews, and your Microfocuser is readily detachable for scope transport or
storage.  A plug-type dust seal is also included with the EyeOpener. 

Note that the EyeOpener will not improve your viewing with 1-1/4" eyepieces or with the smaller 2"
eyepieces.  But it is hugely beneficial when used with the larger 2" eyepieces that give you your
widest actual field of view.