c8 vs 8" dob

if you could only have one, would you rather have a gem mounted f10-c8, no goto, or an f6-8" dob, no goto.
both with good mirrors.
the scope would be used for a little of all types of observing.
no photography.

victor truglio said:

if you could only have one, would you rather have a gem mounted f10-c8, no goto, or an f6-8" dob, no goto.
both with good mirrors.
the scope would be used for a little of all types of observing.
no photography.

You asked...

My first serious scope as a used Orange Tube C-8. It's long gone and I don't miss it. Over the years I have had five 8 inch DOBs, they are gone too but only because my 10 inch F/5 is about the same size but more capable.

The C-8 provided some good views, it was not the views that turned me away as much as some of the ergonomic issues as well as the tendency to dew up and to vibrate at the slightest touch.

But I have come to believe that one's choices are mostly about personal preference, I like the simplicity and robustness of the Newtonian, I like the fact that it is easy to disassemble and modify, I can personalize it. I also like the stability of the mount, real time focusing... And of course the views... I do prefer the view through a newt.

Jon

Both are good scopes, but I'd personally prefer the dob for pure visual work. Depending on the mount the dob could be at least as portable as the C8 if not more so. It also offers a wider FoV which is a plus, especially without goto.

Hi Vic,

I had an excellent 9.25 SCT and I now have an 8" f7 Newt on a Dob base that I vastly prefer to the SCT. With properly installed cooling fans and a 3 vane spider this Newt is a true pleasure to use. Planetary viewing with binoviewers with this scope is unbelievable.

Clear Skies,

Steve

Make it 6 - zip

I've not had a lot of experiences with Cats so it is a limited experience sample from me (I'm sure they are fine instruments too)...but I have preferred the views from my humble dobsonian reflectors.

As an added bonus, I've felt very comfortable "tweaking" my dobs to suit my taste in terms of balance and handling.

I'll go against the grain and say the SCH. A dew shield will take care of the corrector. The longer focal length of the SCH produces great planetary images. The SCH is more compact, most have tracking motors. You can flock a SCH as well for better contrast, the setting circles aid in finding objects. I like the looks of them. The mirrors on 99% of them never need to be recoated ever. Once the mirrors are aligned it will last a long time. There are all kinds of accessories for a SCH to keep you interested. I like the looks of them (I know I said that before). My quick look scope is a C8, my other quick look is a 10" dob.
The 10" wins barlowed and that's the way to go not the 8's. If I had to choose I'd however keep the C8 because it's timeless.
Now if you still want the reflector the question was 8" f10 eq mount or 8" F6 dob and I just realized the 8" f10 is going to be 80 inches long! The choice is easy here the 8" F6 as you will need a ladder or small step stool on the 8" F10 at the zenith, no fun at all. You can barlow the 8" f6 and compesate easily and the field of view on the 8" F6 will be wider for a given eyepiece. The 8" f6 dob will be the easist to use of the 3 but I still like the C8. You can't have just one you know. I never will.

Regards,
Greg

I have both a C8 and an 8" f/6 Dob, and if you restrict the C8 to a non-goto GEM, the Dob wins easily. However, my C8 is most often used on a Voyager mount, and the combination is quite a lot lighter and more portable than the Dob. Plus it has slo-mo in both axes (a huge plus for high-power viewing) as well as a more comfortable viewing position. The Dob has premium optics and is slightly contrastier on planets, but I prefer the C8 most nights simply because I can carry the scope and mount outside in one trip, and I love having slo-mo.

Lots of trade offs. I will agree with the post that suggested not messing with a gem if you are not doing imaging. I think that comfort and convenience are too often overlooked as elements of quality viewing.

If you are the type who likes a quick peak and then move on to the next item on the list, then the comfort of the viewing position is not all that big a deal. If you like lingering for a while or sketching or just gazing, then the way a fork or alt az sct treats your body is a welcome thing. I can view most of the sky for long periods in comfort. I think I view better and see more when my neck is not bent at angles to my body. Then there is the tracking that is usual on the fork mounts. I think that promotes deeper viewing.

Likewise, I prefer the range of viewing positions in a fork SCT to the range of a dob.

But an SCT needs some care. It must be cooled and it must be dew protected. I use a Cat cooler and I have yet to need more than my dew shield here in Texas. But mostly, they must be collimated. Not as often as a newt, but way too many never bother or get used to soft stars or just don't know how. The difference between a collimated and in uncollimated SCT is usually the reason for the bad rep they get.

victor truglio said:

if you could only have one, would you rather have a gem mounted f10-c8, no goto, or an f6-8" dob, no goto.
both with good mirrors.
the scope would be used for a little of all types of observing.
no photography.

My vote is an alt-az mount, either type ota.
Neither will work well if not cooled and collimated.