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| My most recent efforts have been with a Stellarvue
SV80S, 3 element 80mm f/6 APO. The SV80S is an excellent
instrument visually; pinpoint stars across the entire field of view with
jaw dropping contrast, making it an outstanding astrograph, for which it
was specifically acquired. Unlike the 80ED, the APO can image without
a UV/IR block filter - excellent for galaxies and globulars - and the shorter
focal length provides an appreciably wider field of view with my relatively
small format CCD camera. When I have camera alignment and focus spot-on,
stars are small points in my images, even the bright bluer stars, which
tend to bloat up with the 80ED. The SV80S is solidly built, compact
and relatively lightweight, with a smooth operating Crayford focuser.
I think we're going to be spending a lot of time together.
I'm using a piggybacked SV66ED as a guidescope, replacing the Orion 80ED. The extra aperture of the 80ED was welcome for guiding, but not its weight -- the 80ED's proportions and weight are more like that of a 100mm telescope. By going to the lighter SV66 I shed over ten pounds from the overall setup, as I am able to eliminate one of the 7 lb., counterweights. The SV66ED optics are excellent, and, like the SV80S, it also utilizes a smooth operating Crayford focuser. The focus drawtube is threaded for SCT accessories, making it simple to mount the Atik 2HS with T-thread fittings. I am using a variable eyepiece projection unit, without an eyepiece, between the drawtube and camera. A very solid arrangement. The Losmandy GM8 has proven to be an excellent platform for astrophotography. The entire system is incredibly rigid and very smooth operating. Polar alignment typically only consists of proper placement of Polaris and two neighboring stars on the reticule in the polar alignment scope. Alignment seems quite adequate for imaging at 3-4 arc seconds per pixel. |
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| I'm using an Atik ATK-16 monochrome CCD camera for deep sky imaging. The ATK-16 utilizes a 1/2 inch interline CCD, Sony ICX-429ALL (752x582 resolution w/ 8.6u x 8.3u pixels), is a 16 bit system and is peltier cooled to roughly 25 degrees C below ambient. Images typically show extremely low noise, even at exposures of 20 minutes, often doing away with the need for dark frame subtraction. The ATK-16 is shown here mounted on an Atik manual 5 position filter wheel with a Televue 0.8x focal reducer / flattener. |
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| I'm utilizing a StellaCam II
monochrome frame integrating video camera with a fast 50mm cine lens as
a finder scope on my system. This setup gives me a 7.5 x 6.0 degree
field of view on my 9" video monitor, and at 8 second frame integration
will show all of the Messier objects and many of the brighter NGC objects.
Typically I only need roughly point the scope at the region of sky where
the target object is located, then center the object on the video monitor
screen. The live video image is also useful for spotting satellites
or planes moving towards the object being imaged - I can easily cut short
a sub frame exposure to avoid recording the intruding light trails.
And the camera will reveal thin high clouds not visible to unaided eye.
I use Dew-Not defogging heaters on my telescope and video finder objectives, powered by an 8 volt DC variable power supply. These little heating strips are worth their weight in gold on those nights of heavy dew. An Atik 2HS commercially modified web cam is used for auto guiding utilizing
Stark
Labs PHD Guiding software. The software is simple to setup
and insanely easy to use. Initially, some tweaking of drive gears
and scope balance was required, well duh, but I seem to be refining both
and obtaining nice round stars in my images.
. And the beat goes on...... Jim Ferreira
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