Astrophotography with a large Dob? Equatorial?

Hello, all:
There has been some discussion on SAA and elsewhere on whether long
exposure imaging is practical with a Dob or whether the equatorial
platform when used for long term imaging is a kludge. There was a long
presentation of fine long exposure imaging with large Dobs at the June
2003 Apollo Rendezvous in Dayton Ohio People were very impressed with
the results and with the ingenuity it took to do it right..
Actually when doing astroimaging with a large Dob it is not necessary
any longer to choose definitively between a Dob on an equatorial
platform, and a Dob on an equatorial mounting. The CPT design can be
readily shifted from one to the other. Ray Gralak's photos show what can
be done with the 18" version; mounted equatorially..
http://www.astronomy-mall.com/regula...t/imaging.html The 10
inch CPT, which I own and use for observing, is also quite a lovely
scope, very unusual: in design and appearance: :
http://www201.pair.com/resource/reso...10inchcpt.html
Bill Meyers


..

The effectiveness of the platform depends on the model. Some work for
astrophotography and others do not. The suitability of an equatorial
platform for long-exposure astrophotography more or less follows price and
features.

Of course, the same can be said for conventional mounts.

Del Johnson



"Bill Meyers" wrote in message
...
Hello, all:
There has been some discussion on SAA and elsewhere on whether long
exposure imaging is practical with a Dob or whether the equatorial
platform when used for long term imaging is a kludge. There was a long
presentation of fine long exposure imaging with large Dobs at the June
2003 Apollo Rendezvous in Dayton Ohio People were very impressed with
the results and with the ingenuity it took to do it right..
Actually when doing astroimaging with a large Dob it is not necessary
any longer to choose definitively between a Dob on an equatorial
platform, and a Dob on an equatorial mounting. The CPT design can be
readily shifted from one to the other. Ray Gralak's photos show what can
be done with the 18" version; mounted equatorially..
http://www.astronomy-mall.com/regula...t/imaging.html The 10
inch CPT, which I own and use for observing, is also quite a lovely
scope, very unusual: in design and appearance: :
http://www201.pair.com/resource/reso...10inchcpt.html
Bill Meyers


.