To all those owners of DMK Cameras coupled to Lunt Solar Diagonals
I have found another way to reduce the drawtube distance
for DMK Cameras using Lunt Solar diagonals. For low focal
length refractors like the Pronto, Televue 76 and various others
which do not provide enough in-focus for Lunt diagonals
coupled to a DMK camera to achieve proper focus,
most photographers are forced to look for a shorter
nosepiece to fit the DMK camera and they will
likely find even that does not suffice for proper focus. Their
second option is to machine an even shorter one with no
"hip" allowing slightly further insertion into the 1-1/4" eyepiece
tube of the Lunt diagonal. Attempting to avoid all this I
researched devices that would reduce the optical train
AHEAD of the diagonal, and here is one...........
Astro Systems produces a device known as an "Ultra low
Eyepiece adapter - 2" to 1.25" which lowers the profile of any 1.25
eyepiece or optical device another 0.5" below the drawtube.
This allows 2 advantages with the Lunt diagonal - DMK setup:
a) It drops the DMK optical focus opportunity by 0.5" by its design
b) It drops the DMK optical focus opportunity another 0.25 to 0.5"
because a normal 1/1/4" eyepiece adapter is not employed
with its inherent "Hip" protruding from the 2" focuser
The Lunt diagonal fits shugly into it, with the 1/16" thick end
flange resting right against the diagonal face (almost zero
clearance). The result is perfect focus with lots of out-travel.
Problem solved for Lunt diagonal users anyway, but I'm sure it
will help me with other long focus refractors that I have in-focus
problems with when using all sorts of other solar equipment,
and especially with any of the focal reducers on the market.
I seem to remember that both Coronado and further back,
Daystars suffered with the same in-focus problem - always
when attempting to capture the full solar disk by focal
reducers of any sort.
$29.00 from [email protected]
see www.astrosytems.biz/eyepieceadapter.htm for
an image of the device.
Submitted by John Hicks/ Suncityan
Technical - Fitting Imaging Source cameras to Lunt systems
Moderator: marktownley
- Merlin66
- Librarian
- Posts: 3972
- Joined: Tue Dec 13, 2011 1:23 pm
- Location: Junortoun, Australia
- Has thanked: 174 times
- Been thanked: 619 times
- Contact:
Technical - Fitting Imaging Source cameras to Lunt systems
"Astronomical Spectroscopy - The Final Frontier" - to boldly go where few amateurs have gone before
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer
https://groups.io/g/astronomicalspectroscopy
http://astronomicalspectroscopy.com
"Astronomical Spectroscopy for Amateurs" and
"Imaging Sunlight - using a digital spectroheliograph" - Springer