EyeOpener setup for CCD imaging
In general, the EyeOpener will simply attach Meade's Microfocuser to the scope backplate. The camera obviously goes behind the Microfocuser, and if you're using a focal reducer it will go between the Microfocuser and the camera. When using the EyeOpener there is no loss in backfocus distance.
There are 3 separate setups illustrated here, ranging from my first simple attempts at astrophotography to my current more sophisticated setup that's primarily used for astrometry. Just have patience and page down to the one of interest.
Here's the original setup I used for attaching a f/3.3 focal reducer and DSI II Color camera to my 14" GPS.
t EyeOpener to the 3-1/4" male thread extending from the backplate of the scope.
t Next attach the Meade microfocuser to the EyeOpener.
t Next insert the Schmidt threaded adapter (supplied by Meade with the microfocuser) into the microfocuser (smooth end in, threaded end out).
t Next attach the f/3.3 reducer to the Schmidt thread now protruding from the microfocuser.
t Next attach the 30mm spacer to the T adapter supplied with the DSI II to the Schmidt thread now protruding from the microfocuser.
t And finally, attach your CCD imager to the reducer.
The added length of the focal reducer and spacer used up just about all of the scope backfocus.
In this subsequent setup, the DSI IIC is now regulated to use as a guide scope camera, and a DSI III Pro is mounted on the main scope.The DSI II C is now regulated to use as a guide scope camera, and a DSI III Pro is mounted on the main scope. The setup is as follows:
* An EZ Balance on-axis counterweight is held
in place with an EyeOpener.
* The Meade Microfocuser is attached to the EyeOpener.
* A Ted Agos modified Meade f/6.3 or f/3.3 focal reducer is inserted inside of
the Microfocuser. With the longer f/6.3 reducer the tube actually extends
through the EyeOpener and into the scope baffle tube.
* A manual filter wheel is attached to the T-thread on the end of the focal
reducer tube.
* A ScopeStuff manual shutter is attached to the back of the filter wheel, and
the manual shutter is in turn attached to the front of the DSI III Pro. (An
Outback cooler has since been added to the back of the DSI III Pro).
The optics in the modified focal reducers can be positioned anywhere in the new focal reducer tube, eliminating the need for T-tube extension parts. Backfocus is no longer a problem.
After about 18 months of heavy use my DSI III Pro seems to have died. Since I viewed taking "pretty pictures" as part of my learning curve to scientific observations, and since I'd failed to achieve MPC quality astrometry with the III, I made the conversion to SBIG's ST-8XME - complete with CFW-9 and AO-8.
An EyeOpener is screwed onto the backplate of the 14", and the microfocuser is attached to the EyeOpener.
The AO-8 female thread engages the male thread of the Agos modified focal reducer. An older Meade focal reducer (one with a 250mm focal length) is completely inside Meade's microfocuser.
The SBIG "D ring" that normally fits betwen the AO-8 adaptive optics and the CFW-9 color filter wheel has been removed to minimize the distance between the focal reducer and the CCD chip. Effective f/ratio is f/5.0 SBIG's automatic contrast adjustment emphasizes the vignetting, but in practice, if the EyeOpener is in place vignetting ismminimal and easily controlled with flats. The offset guideing CCD is also slightly vignetted but if I'm willing to offset my target slightly I can usually find a guide star bright enough to track at somewhere between 2 Hz and 10 Hz using the adaptive optics.
The setup would look exactly the same when at prime focus (f/10). Internally, the Agos modified focal reducer would be replaced by a male T-thread to 2-inch tube adapter section between the AO and the Microfocuser.