EPSILON - 180
Some images taken using Epsilon-180:
Amazing image taken by Martin Campbell, Dungannon, NI, using a modified Canon EOS 50D at ISO800
Also taken by Martin Campbell using a Canon EOS 5D MKII
Takahashi introduced this awesome astrograph with an incredibly fast photographic speed, to meet the demands of modern large chip CCD cameras, including digital SLRs, as well as deep sky video cameras such as the Stellacam 2. The 180mm aperture Epsilon has a focal length of only 500mm, and a focal length of f/2.8. The above picture shows the E-180 on EM-200 mount.
A B C D
A. The Epsilon 180 tube assembly measures 570mm long, with an outside diameter of 232mm, and weighs 10.7Kg (23.5 lbs). It can easily be mounted on EM-200 (20Kg) capacity, or EM-400 (35Kg).
For more details on EM-400, including details of mounting plates, click here Note that the tube rings and top cross-plate are included when ordering the tube assembly complete with finder, but not the lower mounting plate, except when the E-180 is ordered together with a Takahashi mount. If you already have a Takahashi mount, then you will need to order the lower plate separately. Note also that if you order the bare ota, as is the case with all Takahashi instruments, the cradle/tube rings are not included, allowing you to make your own arrangements.
B. Close-up showing the focuser. The large capstan wheel enables the whole focuser and camera assembly to be rotated to any position in order to frame a field as required. The 2 element ED field corrector is integral to the focuser and connection to the CCD camera is via a Wide T-thread, which has a M54 x 0.75mm thread. The back-focus from the end of the focuser is 56mm, which is the standard for film and digital SLR cameras. Thus a Canon EOS can be directly mounted using a Wide T-Ring. Also included with the tube assembly are adapters for 1.25" eyepieces, for visual observation or for use with a deep sky video camera such as the Stellacam 2.
C and D. Views of the spider showing the considerable offset of the secondary mirror, and the collimation adjustment screws. The secondary mirror measures 80mm on the minor axis.
E F G H
E. View looking into the E-160 focuser, with reflection of my digital camera in the centre. Note the two focus knobs at right. For fine focus adjustment a MEF1 microfocuser can be fitted - details of this are on the TSA-102 page - click here. The whole assembly rotates and is locked at any desired angle by the silver knob at top left.
F. View showing a mounting plate for a finder or other accessory. Brackets for Takahashi finders can attach to the mount plate either directly or using the FQR-1 quick release plate - details also on the TSA-102 page.
G. There is another mounting plate at the mirror end of the E-180. You could use one plate for an optical finder, and one plate for a video finder, such as Stellacam 2 with eg 16mm lens
H. View of spider end showing reflection off primary mirror. The primary mirror is actually oversized at 190mm, which ensures superb accuracy all across the 180mm usable field
Great image taken of M31 by Martin Campbell from Antrim. This shows what can be done with a DSLR ! Martin took 38 exposures of 2 minutes each, using a Canon 20DA at ISO 1600. Click on image for larger version.
For CCD imagers, the image circle is 44mm (60% non-vignetting), which means that the full diagonal of a 35mm frame is covered, and the 100% field is larger than a full circle can be accommodated in a 35mm frame, which measures 36mm x 24mm. EOS and other cameras with chips that are 2/3 the size of 35mm, will have very nearly 100% non-vignetted field. At a 500mm focal length the image scale is 2.7" of arc per pixel, for a CCD with 6.5micron pixels.
Fields of View for 2/3 35mm size chip, and for full 35mm size chip:
Horiz° Vert° Diag°
2/3 x 35mm 1.8 2.75 3.3
Full 35mm 2.75 4.1 4.9
Top of Page