Orange C8 with Dave Ek's DSCs, SkyWatcher 12" Collapsible Dob, iOptron MiniTower, iOptron SmartEQ Pro, AstroVideo System Advanced Cam MkIi, Samsung SDC-435, Philips CCTV f/1.6 12-240mm zoom lens with Cosmicar 2x extender, and more junk than I can list
Quote:2) What would be a good upgrade or companion to an 8 inch dob I have been looking at the Celestron NexStar 8SE but it is a go-to type, I would prefer to put my money into aperture and quality of mount / optics as I won't be getting into photography.
Quote:Hi guys,I like to think I know a fair amount about dobs but I know very little about SCTs. I am looking to buy or upgrade my 8 inch dob to a better and more powerful scope and I was considering a SCT as opposed to a bigger dob. I was hoping I could have some opinions on this.I do have a few questions regarding a SCT.1) Can I use 2 inch eyepieces in them by just adding a 2 inch diagonal?2) What would be a good upgrade or companion to an 8 inch dob I have been looking at the Celestron NexStar 8SE but it is a go-to type, I would prefer to put my money into aperture and quality of mount / optics as I won't be getting into photography.3) what are the main differences at the eyepiece between the dob and SCT?Any suggestions on piecing together a 8 or 10 inch SCT?Thanks!
George RoffeKingwood, TX
Quote:The field of view is half in the C9.25 what it is in the Newt.
Quote:Quote:The field of view is half in the C9.25 what it is in the Newt.This does not tell the full story. If you put the same eyepiece into each scope then the above is a true statement, but that is kind of misleading. If you have a Newtonian and an SCT that have the same aperture (so an 8" Dob and a C8), they will produce the same TFOV, image brightness and exit pupil if the magnifications are equal. Depending on the eyepieces you have available to you this may not be possible, but the design of your telescope does not determine the true field of view. Magnification and the AFOV of your eyepiece determine how much sky you will see.
Celestron Ultima 8 (1991) with a white tube (sold by Vixen) Orion Express 80 on a CG-4
Fujinon 7 X 50 Binoculars
Williams Optics 8-24 mm Zoom(type 1)
Orion Ultrascopic 5 mm
University Optics 6,7 mm
Explore Scientific 80 deg 6.8mm,8.8 mm, 11 mm, 18 mm Meade UWA: 24 mm
Meade SWA: 40 mm Orion Shorty II Plus Barlow
Zhumel Planetary 18mm 1.25"
Quote:Sorry but it does, a C8 SCT is limited in its TFOV to approx 1.3 degrees because of the size of the baffle tube on the SCT which is limited itself by the central obstruction and the size of the hole in the mirror. I LOVE my SCT but its strengths are not in its ability to be a wide field instrument. The best "2nd" telescope in my opinion is a small refractor.
Quote:Panning around and viewing wide areas of the sky is where a small refractor excels.
Quote:but a refractor will need cool down time too, and if its a triplet it may be worse/ longer then the c6
Quote:8" SCT is not bigger/ more powerful than 8" dob. For a good jump in aperture, think 4 inches more than your 8". C11 or C14, but unless you have a desire for Fork or GEM mounts and goto, upgrading to a 12" dob would make more sense. Get a dob with Computer Object Locator like the XTi series or a custom dob with Argo-navis or Sky Commander and encoders. Truss type dob would be more compact for storage. A Paracorr and low f ratio is good. Wider fields than an SCT, even if less compact package than an SCT and a truss type might actually be more compact for storage.
Happy owner of-- A Mag 1, 12.5 inch Porta Ball A Dual Axis Equatorial Platform A PST Double Stack
Quote:Agree with this. I recommend you double the light gathering of your 8, not get another 8. That would take you to an 11/12 SCT or 12 inch Dob. You are familiar with a Dob. I recommend visiting your local astronomy club's star party. There will be several SCT's. If there is not an 11 or larger, you will be able at least to look over an 8.