MikeyB
28-05-2011, 02:30 PM
SOLD
Meade’s f/3.3 CCD focal reducer converts an f/10 Schmidt-Cassegrain telescope to a fast f/3.3 system for imaging with small chip CCD cameras and DSI-type cameras. The focal reduction yields a wider, flatter field for imaging large deep space objects and reduces CCD exposure times by up to 80% for ultrafast imaging. It also yields increased edge of field resolution and color correction.
Mounted in its threaded cell, the f/3.3 reducer attaches to the rear cell of any Meade LX-Series Schmidt-Cassegrain scope, or to the rear cell of any Celestron 5" through 14" Schmidt-Cassegrain. Because of the reducer’s very short back focus, the CCD camera attaches directly to the reducer using the T-threads on the reducer. Adding a color filter wheel between the reducer and the camera will usually add enough distance to prevent the camera from reaching focus.
Attaching it to an f/10 Meade LX200, for example, reduces its focal length by 67% and exposure durations by 90% and gives an increased field of view for CCD imaging. The field illuminated by the f/3.3 image is small however, so this focal reducer is not suitable for DSLR or large chip (35mm-size) CCD cameras and cannot be used for visual observing because of severe vignetting.
Included with the focal reducer is a variable T-adapter for attaching the CCD camera to the reducer, which allows the choice of an additional f/3 or f/5 focal ratio with an f/10 SCT scope. The variable T-adapter comes in three sections. The first attaches to the focal reducer and provides a T-thread connection 7mm from the reducer lens. There is then a 15mm extension tube and a 30mm extension tube that can be screwed on, allowing the CCD camera to be attached either 7mm, 22mm, 37mm or 52mm from the reducer lens.
The focal reducer’s 3-element, 41mm clear-aperture optics are multi-coated to maximise light transmission. It has plastic dust caps for both sides of the lens assembly and stores in a protective bolt-type plastic case. A rubber grip ring on the body allows for easy installation of the reducer on your scope.
In excellent condition, this Meade f3.3 Focal Reducer is complete with all parts and caps as shown in the photos and also a plastic bolt case for convenient storage. Only $140, including careful packing and registered postage to anywhere in Australia. Inquiries by PM only, please.
Meade’s f/3.3 CCD focal reducer converts an f/10 Schmidt-Cassegrain telescope to a fast f/3.3 system for imaging with small chip CCD cameras and DSI-type cameras. The focal reduction yields a wider, flatter field for imaging large deep space objects and reduces CCD exposure times by up to 80% for ultrafast imaging. It also yields increased edge of field resolution and color correction.
Mounted in its threaded cell, the f/3.3 reducer attaches to the rear cell of any Meade LX-Series Schmidt-Cassegrain scope, or to the rear cell of any Celestron 5" through 14" Schmidt-Cassegrain. Because of the reducer’s very short back focus, the CCD camera attaches directly to the reducer using the T-threads on the reducer. Adding a color filter wheel between the reducer and the camera will usually add enough distance to prevent the camera from reaching focus.
Attaching it to an f/10 Meade LX200, for example, reduces its focal length by 67% and exposure durations by 90% and gives an increased field of view for CCD imaging. The field illuminated by the f/3.3 image is small however, so this focal reducer is not suitable for DSLR or large chip (35mm-size) CCD cameras and cannot be used for visual observing because of severe vignetting.
Included with the focal reducer is a variable T-adapter for attaching the CCD camera to the reducer, which allows the choice of an additional f/3 or f/5 focal ratio with an f/10 SCT scope. The variable T-adapter comes in three sections. The first attaches to the focal reducer and provides a T-thread connection 7mm from the reducer lens. There is then a 15mm extension tube and a 30mm extension tube that can be screwed on, allowing the CCD camera to be attached either 7mm, 22mm, 37mm or 52mm from the reducer lens.
The focal reducer’s 3-element, 41mm clear-aperture optics are multi-coated to maximise light transmission. It has plastic dust caps for both sides of the lens assembly and stores in a protective bolt-type plastic case. A rubber grip ring on the body allows for easy installation of the reducer on your scope.
In excellent condition, this Meade f3.3 Focal Reducer is complete with all parts and caps as shown in the photos and also a plastic bolt case for convenient storage. Only $140, including careful packing and registered postage to anywhere in Australia. Inquiries by PM only, please.