Peterson Engineering Eye Opener II 2 Inch Visual Back
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Specifically designed for telescopes using Meade’s #1209 Zero Image-Shift electronic microfocuser. It threads onto the 3-1/4″ male thread found on the backplate of 10″, 12″ and 14″ Meade SCTs. scopes, removing the 1 1/2″ Schmidt thread adapter restriction and providing the full 2″ unrestricted optical path that you already have in the microfocuser and the baffle tube.
Unscrew your 1-1/2″visual back and check it out for yourself.
Increase light reaching your eye or camera chip by as much as 65%!
For all Meade 10", 12" and 14" SCTs
(includes LX850, LX600, LX400ACF, RCX-400, LX200ACF, LX200R, LX200GPS,
LX-90GPS, LX90 & LX200 Classic)
Visual observer? 2" eyepieces are "where it's at" for widest field of view. An EyeOpener enhances the performance of long focal length 2" eyepieces on Meade 10”, 12" and 14” SCTs by increasing the optical path size from 1 1/2" to 2". Get all of the eyepiece aperture that you paid for while enjoying the full benefit of 2" eyepieces.
Imaging? With all but the smallest (oldest) chips, all SCT camera setups suffer from vignetting (darkness at the corners of the image). Increasing your scope's optical path from 1 1/2" to 2" in diameter is almost mandatory for today's imagers.
History: As Schmidt-Cassegrain Telescopes (SCTs) evolved from 8-inch models to larger-aperture scopes, and as eyepieces evolved from 1¼" to 2", the "Schmidt-thread" couplings used for securing 1¼- inch diagonals and eyepieces to telescope backplates remained unchanged. This "Schmidt visual back" supplied with Meade (and Celestron) SCTs has an internal diameter of 1½", and it functions as a 1½ inch-diameter field stop. This field stop effectively limits the performance of modern 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! For imagers, the same holds true for your camera chip.
Note that there are inexpensive Schmidt thread to 2" tube adapters being marked that may use the phrase eye-opener. They do not increase light throughput as the problem is the inside diameter of the Schmidt thread itself.
Low profile. Adds no additional back focus over the height of the original Meade visual back.
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 SCTs. scopes, providing a full 2" unrestricted optical Meade's microfocuser (or the Peterson 2" EyeOpener Tube Adapter) attaches directly to the EyeOpener. Unscrew your 1-1/2"visual back and check it out for yourself. To use the EyeOpener on scopes not equipped with Meade's microfocuser, or to shorten the optical path by eliminating the Microfocuser you will also need an EyeOpener 2" Tube Adapter. As an alternative, the EyeOpener will also allow LX90 and LX200 Classic SCT owners to retrofit Meade's #1209 Zero Image-Shift Microfocuser or JMI's EV series manual and electric focusers.
Microfocuser mounting thumbscrews now included. Do you recall the old proverb about the added straw that broke the camel's back? Meade's big SCTs are heavy enough to transport without the added 1-1/4 pound weight of the Meade Microfocuser. Replace the 3 mounting set screws in the Meade 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. To see how various eyepieces will perform on an SCT click here
The EyeOpener 2-inch Visual Back
- Increase light reaching your eye or camera chip by as much as 65%
- It’s the equivalent of buying the next size bigger scope.
- Fits all Meade 10″, 12″ and 14″ SCTs
Visual observer? 2″ eyepieces are “where it’s at” for the widest and brightest field of view. The EyeOpener enhances the performance of 2″ eyepieces on Meade 10”, 12″ and 14” SCTs by increasing the optical path size from 1 ½” to 2″.
Imaging? With all but the smallest (oldest) chips, all SCT camera setups suffer from vignetting (darkness at the corners of the image). Increasing your scope’s optical path from 1 ½” to 2″ in diameter is almost mandatory for today’s imagers.
History: As Schmidt-Cassegrain Telescopes (SCTs) evolved from 8-inch models to larger-aperture scopes, and as eyepieces evolved from 1 ¼” to 2″, the “Schmidt-thread” couplings used for securing 1¼ inch diagonals and eyepieces to telescope backplates remained unchanged. This “Schmidt visual back” supplied with Meade (and Celestron) SCTs has an internal diameter of 1 ½”, and it functions as a 1 ½” inch-diameter field stop. This field stop effectively limits the performance of modern 2″ optics to the equivalent of 1 ½” optics. When using the 1 ½” visual back with Meade’s 2″ 56mm Plossel (an eyepiece with a full 2″ of glass in the nose) you lose 65% of the light to your eye! For imagers, the same holds true for your camera chip.
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.
For a technical explanation of vignetting and how the EyeOpener makes viewing brighter and images both larger and brighter press button.
In the 2008 -2009 period Meade 14″ scopes used a redesigned baffle tube assembly that severely constriction the optical path. A subsequent late 2009 redesign reopened the optical path to a full 2″. Check out your configuration if you have a 2008-2009 era scope. This is for 14″ only.
There are many inexpensive Schmidt thread to 2″ tube adapters being sold. They allow mounting 2-inch optics but DO NOT increase light throughput as the problem is the inside diameter of the Schmidt thread itself.
For information on how to use the EyeOpener with a focal reducer for ccd imaging click here
You ain't seen nothin 'till you've looked thru the EYEOPENER
NOTICE OF POSSIBLE 14" INCOMPATIBILITY: Meade 14-inch LX200ACF scope owners note: The baffles in 14" scopes manufactured prior to late 2008 reduce the maximum optical path to 1.75" diameter. The EyeOpener will still significantly increase your light throughput by 31% 14" Meades manufactured since late 2008 exhibit 2 different major backplate and baffle redesigns - one opening the optical path up to a wonderfully full 2 inches and the other constricting the optical path to very restrictive 1½ inches. Both redesigns utilize baffle tubes held in place with a spanner wrench notched ring. The thread on the outside of the ring mounts Meade's visual back, and will also mount the EyeOpener. If you own the revision with the full 2" optical path, congratulations. If you own the revision with the baffles restricting the ID to 1½", the addition of an EyeOpener will not increase the light throughput or the actual field of view of your telescope. If you have a revised 14" measure your baffle ID to insure that the EyeOpener will benefit you.
From Florida: " I don't know if you remember speaking to me last week but I order the EZ Counter Weight from you and we discussed the Eye Opener and I also purchased one of them. The weight worked great.... The reason for my E-Mail is that Eye Opener. I installed it (Easy as Pie) and used it for the first time tonight. I emailed two of my friends tonight talking about how unusually great the viewing was tonight. The weather here in Florida is cold and clear skies. But I've viewed nights just as clear. I told both of them ... how the Orion Nebula took up my entire field of view in that 31mm Nagler with all kinds of nice wisps I had never seen before even with my expensive filters. Tonight no filters and view was awesome. Same with other targets too. The Double Cluster was particularly great tonight. Little fuzzy's weren't so fuzzy:) Then right in the middle of my email to ..... I stopped and said. "Holy Cow" I did not even think of this. Is this because of the Eye Opener:):) ...... What do you think? I'll tell you what, if this is the case than that Eye Opener is the greatest single invention to help these scopes that can possibly be made. I then came back to your web site and read more. That part about the 65% increase in light that gets to your eye and the part about it's like adding 2 inches of aperture to your scope has pretty much got me convinced it's the Eye Opener who should get the credit for tonight's great viewing. I can't believe Meade makes a 2" eyepiece holder and backs it up to a 1 1/2 hole. That's like putting a potato in the exhaust pipe of your car:) Any way, let me know what you think.
12 inch GPS Nagler Powered with the Eye Opener Power Port"
From MAPUG "I own a 40mm SWA (Meade) and noticed that on the standard VB on my 12" LX200, the vignetting was so bad, I almost took the eyepiece back. It seemed that almost 10% of the outer edge of the FOV was blurred. When I put this eyepiece in the EyeOpener, the difference was drastically different. Stars were crisp, even at the very edge. Now, I haven't sat down a measured anything, but I have tested it with the eyepiece and it does make a huge difference (at least with this eyepiece)."
From California: "Thanks for a great product. My 2in EP views are noticeably brighter. Another benefit realized with the Eyeopener is that it decreases the distance that the EP is located relative to the telescope back 13/16 of an inch by eliminating the AP SCT diagonal adapter. This gets me a closer to the 100mm distance that the optics are optimized for (spherical correction). My inside focus diffraction pattern is crisper. I calculated that the original AP diagonal combo lengthened the FL to 3000mm instead of the advertised 2800mm on my C11. I should be closer to 2800mm now."
From MAPUG: "I own a 40mm SWA (Meade) and noticed that on the standard VB on my 12" LX200, the vignetting was so bad, I almost took the eyepiece back. It seemed that almost 10% of the outer edge of the FOV was blurred. When I put this eyepiece in the eyeopener, the difference was drastically different. Stars were crisp, even at the very edge. Now, I haven't sat down a measured anything, but I have tested it with the eyepiece and it does make a huge difference (at least with this eyepiece)."