TAKAHASHI FS-60CB
The FS-60CB is based on the highly successful FS-60C, f/5.9 doublet, the essential difference being the length of the main tube. The original tube of the FS-60C was 145mm, that of the short tube FS-60CSV was 105mm, and that of the FS-60CB is The normal ota is supplied with a 1.25" focuser as shown. The focal ratio is 355mm, and a field flattener is available for prime focus imaging. There is a new focal reducer, to give 0.72x the normal focal length.
System Chart, and comparison with FS-60C (pdf)
Extender C x2 system chart (pdf)
Specification
Objective 60mm fluorite doublet
Focal length/focal ratio 355mm f/5.9
Resolving power - 1.9" of arc
Overall length - 440mm
Weight - 1.4Kg
1.25" eyepiece adapter standard
Optional prime focus field flattener - focal ratio 370mm, f/6.2, image circle 45mm
Optional focal reducer - focal ratio 264mm, f/4.4, image circle 44mm
Optional x2 doubler - focal ratio 710mm, f/11.8, image circle 35mm
See price list for full details. Tube assemblies are at the start of the price list, accessories at the end of the price list.
See also photo visual chart above
CSV tube 2" Back
For use with binocular viewers, and some imaging applications that require more back-focus, an optional short tube (CSV) can be used. The CSV tube is 105mm long compared to 127mm length for the FS60CB tube. To change from standard to CSV tube simply unscrew the objective cell and focuser from the standard tube and screw them onto the CSV tube- no collimation is required.