Baader Spacer Set for MPCC SPCR-SET2
Item No. 724-40006
Manuf. No. Baader Planetarium T2-25A
Directly-Coupled Configurations for 2" Eyepieces
The ideal way to use the MPCC for visual use with 2" eyepieces is to directly couple it to the eyepiece, via the eyepiece's 2" (48mm) filter threads. This allows the MPCC to be accurately positioned, providing the optimum spacing for top performance and taking the guesswork and error out of setting a continuously variable holder. The rigid coupling also eliminates the possibility of sag or tilt from variable holders, particularly with the largest and heaviest eyepieces. This configuration also enables the MPCC to work without needing any additional back-focus. In this configuration, the eyepiece will actually come to focus about 10mm further OUT than it does without the MPCC. Since most large Dobs are limited in their back-focus, this may be the only way to achieve coma correction with some eyepieces (short of trimming truss poles..). Dob users will also appreciate the light weight of the MPCC system, which avoids the balance problems of heavier correctors.
Here are examples of direct-coupling the MPCC to some popular wide field 2" eyepieces
For best performance, the corrector should be positioned approximately 55mm from the rear mounting face of the MPCC housing to the eyepiece's field stop (+/- 3mm for best on-axis sharpness). In order to attach and properly locate the MPCC, only 1-3 inexpensive adapters are required. We also offer a convenient spacer set, that will give you the spacers needed to fit the majority of 2" eyepieces. Please see the Spacer Tube and Adapter section, below, for a listing of available spacers.
- MPCC + T2-29 + HDFT14 + Nagler 17
- MPCC + HDFT28 + Nagler 20 T2
Configurations for 1.25" Eyepieces
To use the MPCC with 1.25" eyepieces, the only additional parts required are the T2-15 Reducer/Eyepiece Holder and one or two spacer rings. The result is a compact and lightweight coma-correcting assembly that slips completely within a 2" focuser. This configuration guarantees focus in all dobsonians, even those with very limited back-focus. The T2-15 eyepiece holder incorporates a captive bronze compression ring and two large knurled screws, for a rock solid no-mar clamping of even the largest eyepieces. For short focal length eyepieces where coma-correction is not needed, simply remove the MPCC and the T2-15 goes back to being a high-quality 2"/1.25" reducer (threaded for 2" filters). Note: When used in this configuration, the T2-15 provides 37mm of spacing.
Here are examples of 1.25" MPCC configurations
For best on-axis performance, all coma correctors need to be located at the correct distance from the eyepiece focal plane. The MPCC system makes accurate location simple, rigid, and consistently reproducible through the use of threaded spacer rings. In order to attach and properly locate the MPCC, only 2-3 adapters are required.
- MPCC + HDFT28 (or HDFT14) + T2-15
- MPCC + T2-25A + T2-29 + T2-15
Spacer Set of Tubes and Adapters for MPCC:
- Hyperion Finetuning-Ring 14mm long (HDFT-14)
- Hyperion Finetuning-Ring 28mm long (HDFT-28)
- T-2 Extension Tube 15mm long ( T2-25A)
- T-2 Extension Tube 7.5m long (T2-25C)
- T-2 Expanding Ring, T2/M48 (T2-29) (converts 2"/M48 filter threads to internal T-threads)
- T2-15 Eyepiece Holder and 2"/1.25" Deluxe Reducer (T2-15)