TAKAHASHI FS-60CB
The FS-60CB replaces the very popular FS-60/FS-60CSV, simply in the length of the main tube (see comparison info on pdf file below)
In addition to there being a field flattener for CCD imaging, a 0.72x focal reducer has been announced, which provides amazing wide-fields of view due to the very short focal length of only 264mm, and fast at f/4.4. Below is a beautiful image of the Veil Nebula by Bob Winter , using the focal reducer on his FS-60CB
Click on image to enlarge. Camera was QSI 583, LRGB image using Ha and OIII CCD
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 - 0.72x, 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
FS-60 on camera tripod FS-60C on TGSP-II mount Photo-Visual Chart
The amazing FS-60C is a vesatile f/5.9 doublet, and is the perfect small scope for going anywhere, anytime. 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.
One can go even wider field by use of a focal reducer/field flattener - see photo-visual chart above.
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 145mm length for the standard 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.