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The focal plane evaluation shown to the right was created using
CCD Inspector.
It shows the symmetry and quality of the field
of a 16" f3.75 Dream Astrograph
that was tested in April of 2010 in Dream's observatory. The
telescope was extensively tested over four nights. Shane Santi
performs these tests personally for each and every telescope
Dream produces, and has been for seven years. The
CCD used is a KAI-11002 chip: 9 microns square, 4008 x 2672 (42mm
diagonal). |
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Click on either of the CCDI graphics to download the raw
FITS file. |
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Collimation of this and all of the Dream Astrograph telescopes
was achieved by using the custom
3" Catseye collimation tools that Dream had developed
specifically for these telescopes. Collimation of the telescope
was done during the day. No collimation adjustments were
needed to the telescope itself at night (CCD). We have found
that the proper use of the collimation tools and the design features
of the Dream Astrographs eliminates the need for non-intuitive
collimation adjustment of the telescope optics (CCD). |
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Dream and our customers have also found through empirical test
results that our state of the art telescopes not only hold focus
across temperature changes but the telescopes hold collimation
across the entire sky. This
is a huge accomplishment for a system with a depth of field of
only 30 microns, used on equatorial mounts (constantly changing,
compound angles of the telescope) and with large CCD chips. |
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"Within a temperature
range of 10 degrees C we see no measurable change in focus. Also,
there was no change in focus as a function of telescope position.
All thanks to rigid
carbon fiber." |
- Michael Schwartz, Tenagra
Observatories, 16" f3.75 Dream
Astrograph owner.  |
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"I went to bed at about
10PM and I let it run all night without focusing. I blinked through
the images and focus did not
change. Also, I did all of my other images by letting it run
through the night without focusing." |
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- Mel Helm, Sierra
Remote Observatories, 16" f3.75
Dream Astrograph owner. |
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