16
Manual: Cool-Ceramic Safety Herschel Prism Mark II
Shortening the overall length for connecting long accessories
The overall length of the Herschel prism can be shortened by 28-29 mm by replacing
the 30 mm long 2" eyepiece clamp with one of the Diamond Steeltrack
®
S58 adapters.
A connection thread is then available directly on the prism housing.
Many manufacturers of refractors do not design the focal point position behind the
end of the focuser with a large enough allowance to connect alternative accessories
from other suppliers. In particular, SLR cameras with 55 mm flange focal length usually
do not come into focus behind a 2" star diagonal or the Herschel prism: To avoid vig-
netting caused by the retracted focuser, the telescopes are designed so that a DSLR
can only come into focus without additional accessories.
In this case, the S58 adapters to T-2, M48 or M68 described on page 6 are the solu-
tion to shorten the mechanical length of the Herschel prism by 28-29 mm by removing
the 2" ClickLock
®
clamp and still attach the absolutely necessary 2" ND 3.0 filter and
the 2" solar continuum filter at the same place directly above the Herschel prism in the
beam path.
To connect, proceed as follows, using the T-2 adapter
# 2957202
as an example:
1. Remove the 2" ClickLock
®
eyepiece clamp
by unscrewing the six hexagon socket
screws with the 1.3 mm hex key. It is not
necessary to unscrew them completely. The
filter holder with the filters remains mounted
in the Herschel prism.
2. Place the S58 adapter on the rotating filter
holder, hand-tighten the six hexagon socket
screws. The T-2 thread now sits flush with
the housing and can be used.
3.
Example:
Connecting a camera with a T-2
thread.
