|
Custom Coronado SolarMax 90 Telescope (.5Å)
The largest dedicated solar
scope in the current Coronado line, the SolarMax 90 telescope
(previously known as the MaxScope 90) offers an amazing, eye
watering view of the sun for the amateur solar observer. It's that
good!
This telescope began it's life
as a SolarMax 90 filter with a BF15 blocking filter. The
SM90 was sent back to Coronado and mated to the MaxScope OTA with a
custom BF30 blocking filter, extension and focuser. There's an
additional internal 60mm high
resolution etalon installed at the end of the drawtube (inside the focuser) to bring the bandpass
down to .5 Angstrom.
JMI NGF-C gold anodized focuser
and custom BF30 blocking filter
The gold anodized JMI NGF-C
motorized focuser is matched perfectly to the OTA color and is an
absolute necessity for imaging. It is a solid, substantial focuser
that easily handles the load of a camera or binoviewers. I can
achieve critical focus in a matter of seconds when using the hand
controller. The long tube between the gold focuser
and the black section of the OTA provides several more inches of
additional travel. The AP MaxBright diagonal and 25mm CEMAX are pictured above.
Design
My goal in designing this
scope with Bill Dean (Ex-Coronado) was to create the best possible Ha platform for both visual
and imaging use. The idea was to have the entire system optimized
for Ha usage. The dedicated SolarMax OTA was selected over a
conventional nighttime refractor. A custom BF30 is used for maximum
light throughput. The focuser was replaced with the precision JMI
to allow for a 2" large format SBIG research grade camera. The AP
diagonal reflects 99% of the light passed and blocks IR wavelengths
above 7000Å.
The CEMAX eyepieces are specifically designed for Ha use.
Internal 60mm High
Resolution Module
Performance
First light with this scope
was stunning and I could instantly tell there is a huge difference between the .7Å
and .5Å
Coronado setups. Disk detail is very strong and the contrast between
the light and dark features of the disk is outstanding. Prominences
can be seen easily and are perfectly illuminated. The brightness of the SM90 filter was toned down
to the correct level (for me) when combined with the internal 60. I do not
use a neutral density filter when imaging. Tilting the 90mm filter eliminates reflections within the scope.
See other images through this scope.
Telescope Data
| Focal
Length |
Imaging - f/10, 914mm
Binoviewing - f/10, 933mm |
|
Magnification |
32x (25mm Eyepiece) |
|
Exit Pupil |
1.8mm |
|
Resolution |
1.82" * |
| Weight |
17 lbs. |
*Resolution = {(1.22 x Ha wavelength) / ERF diameter}
x 206265. Where resolution
is in Radians, Ha wavelength is .000656mm, ERF diameter is 90mm and
206265
is the number of arc seconds in one radian.
|
