Backyard Voyager
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Imaging with C9.25/CG5 combinationNext
And finally we come to the reason that Celestron made this scope differently than all other commercial SCTs—a flat field for astrophotographers. In the end it didn't matter. Within a few short years film faded into astrophotography history. CCD fields grew wider, but with so many reasonably priced telescopes and accessories (such as ED refractors and field flatteners) hitting the market with each month that passed, there was less of a need for such an OTA. Ironically, when this scope became one of the OTAs of choice for planetary and lunar photographers, the flat field didn't even matter. These targets were always within the mirror's “sweet spot” anyway. It was the focal length and aperture that attracted the planetary imagers to the SCTs.
There has been some talk on the internet to the effect that this C9.25 is better
Taken with Televue 2x barlow in 10/10
seeing conditions-- 2296 hand-selected
frames stacked in Registax 3.
than other SCTs for planetary or high magnification lunar imaging. If there is any truth to this, then it doesn't have anything to do with the optics. If there is indeed a disproportionately high number of quality images surfacing that were captured with this telescope, then it is probably due to the fact that this OTA is less dependent on seeing conditions and doesn't take as long to cool as the larger SCTs. Under the right circumstances a properly cooled and collimated C14 will, of course, resolve more detail than the smaller scope. With the smaller OTA you just get more chances. So, once again, this isn't a magical scope, but for planetary imaging there are distinct advantages: with 9.25 inches of aperture this scope will resolve a lot of detail and you will have plenty of opportunities.
I could continue for ...., but for beginners the most important aspect of this scope is that the learning curve for this particular equatorial mount and accompanying "goto" system is not at all beyond the capabilitities of any Images of Saturn at magnification levels of 100x to 150x were stunning. At 133x, on nights of excellent seeing, the Cassini division showed up as a sharp, jet black line separating the A and B rings all the way around. Even on nights of mediocre seeing the planet's sphere showed color. On better nights a band and the polar cap stood out.
Jupiter was just as good, but I didn't fully appreciate it until the second year I had the scope. My expectations may have been a little high, and as any experienced observer knows, it takes time to learn how to see. But whenever it faces us the GRS is always apparent with this scope, even on nights of average seeing. I don't believe I've ever failed to see it. What impressed me the most was that, under the best seeing conditions, the larger of the Galilean moons were resolved as tiny spheres rather than points of light. They looked like moons.
I live in a light polluted suburb, where, on the darkest nights of the year, the upper levels of my eastern sky will show stars of 5.0. Normally dark nights will be populated by stars in the 4 to 4.5 range, usually closer to 4. Fortunately we have better than average seeing. During my first year with the C9.25 I saw the entire Messier catalogue from this location. A few of these were difficult, such as M74 and M101, the latter of which took more than a month of searching every night, until we finally had a night dark enough to differentiate between the pale light of the galaxy and the background sky. In M42's Trapezium I can see A through E on a good night. On a very good night I can see all six, the F star popping in and out of view. With the go-to function, this scope showed me 132 galaxies during that first year. I didn't get much sleep.
Jupiter in 2005. Images captured with C9.25" SCT
and Phillips ToUCam, using 2X Televue barlow.
Approximately 300 frames stacked in Registax 3.
And finally we come to the reason that Celestron made this scope differently than all other commercial SCTs—a flat field for astrophotographers. In the end it didn't matter. Within a few short years film faded into astrophotography history. CCD fields grew wider, but with so many reasonably priced telescopes and accessories (such as ED refractors and field flatteners) hitting the market with each month that passed, there was less of a need for such an OTA. Ironically, when this scope became one of the OTAs of choice for planetary and lunar photographers, the flat field didn't even matter. These targets were always within the mirror's “sweet spot” anyway. It was the focal length and aperture that attracted the planetary imagers to the SCTs.
There has been some talk on the internet to the effect that this C9.25 is better than other SCTs for planetary or high magnification lunar imaging. If there is any truth to this, then it doesn't have anything to do with the optics. If there is indeed a disproportionately high number of quality images surfacing that were captured with this telescope, then it is probably due to the fact that this OTA is less dependent on seeing conditions and doesn't take as long to cool as the larger SCTs. Under the right circumstances a properly cooled and collimated C14 will, of course, resolve more detail than the smaller scope. With the smaller OTA you just get more chances. So, once again, this isn't a magical scope, but for planetary imaging there are distinct advantages: with 9.25 inches of aperture it will resolve a lot of detail and you will have plenty of opportunities to capture it. Here is an image I took toward the end of the first year with this scope: