Dobsonian vs SCT is there much difference visual observing

[asset189]

Considering selling 8" dob and 5" newt with synscan to help fund purchase of 8"celestron vx SCT set up for imaging and visual. My question is will I lose out visually with SCT compared with Dob

[Moonshane]

there will be a narrower field of view and more magnification with the same eyepiece but other than that I'd not expect massive dfferences. the dob might be slightly sharper if collimated well and cool. the SCT will possibly take longer to cool and set up. that said, the tracking mount will allow comfortable nudge free observing at high mag.

[Tinker1947]

I think my 10" newt had a slightly sharper view, you might want to find somebody local who has a SCT and try before you buy.....

[nmoushon]

The dobs will have a sharper view due to the smaller CO I believe....but I think you wont be able to notice to much. I think planetary view will show this the most though. But the higher mag, IMHO, would be worth the trade off.

[jetstream]

I understand the C8 goto makes a very good visual package.My buddy is kicking my  _ _s on DSO with his C8 goto.... I do love the dob platform however,so stable.

[brantuk]

There will of course be many differences and one or two similarities. The big thing is the mount. With the AVX you'll have your Sct, but it will also take other OTA's for both imaging and visual. It'll certainly handle an 8" newtonian for observing and you can get one second hand later when budget allows - shouldn't cost much more than £130-£150. Best of both worlds so go for it.

[emadmoussa]

I had the C11 and 2 Dobsonians 10" and 12"...

The difference...

C11 for the aperture is quite compact, but in terms of contrast and image brightness the Dobs won hands down. That's not to say the Schmidt Cassegrain was bad, but I felt it lacked the ''pop-out'' element of stellar objects.

I eventually replaced the C11 with a 10" GSO Dob...

[crashtestdummy]

I found colours seemed to be better in a dob than a simialar sized sct.maybe this is due to the central obstruction or maybe just the wider field,light grasp.I hate motorised mounts,they are so bad news for star hopping.I could see ten times as much in a dob in a session due to quick movability if the dob.

[scarp15]

The 8" SCT is considered as a good all-rounder, compact, retains collimation very well and cools in 45min - 1hr. I only use mine for visual, in which it is very capable / satisfying on all subjects.

[YKSE]

I hate motorised mounts,they are so bad news for star hopping.I could see ten times as much in a dob in a session due to quick movability if the dob.

That just tells how different each observer is. I love the motorized mount, in the lastest 7-8 sessions, I got around 20 new Meesiers/Caldwells/NGCs with C8 on motorized EQ3, I'm not sure I can get 200 new ones with a dob of similar or bigger size in a session.

In my backyard, I can lift out the whole setup in seconds, do the alignment during cooling, then just put my time in observing.

Star-hoping is fun in its way, I just don't see a motorized mount deprive that fun, you can always turn off the motor and use it manually.

[asset189]

Thanks for the info folks, food for thought

[Baffa]

I think SCT's are ideal on EQ goto mounts as visual instruments. Always nice with tracking and goto, lots of aperture in a compact design so you usually have a nice and comfortable viewing position. A big refractor tends to get really long and a newtonian, well, you need trenches or ladders to be able to look into that eyepiece (Or you could rotate the tube but.. haha)

[crashtestdummy]

That just tells how different each observer is. I love the motorized mount, in the lastest 7-8 sessions, I got around 20 new Meesiers/Caldwells/NGCs with C8 on motorized EQ3, I'm not sure I can get 200 new ones with a dob of similar or bigger size in a session.

In my backyard, I can lift out the whole setup in seconds, do the alignment during cooling, then just put my time in observing.

Star-hoping is fun in its way, I just don't see a motorized mount deprive that fun, you can always turn off the motor and use it manually.

by 7-8 sessions do you mean 7-8 hours?i did a 5 hour session in Galloway and got 50+ galaxies and 20+ messiers and that was just new ones and half the time I spent clearing dew from the secondary.a dob is much easier to star hop with,its a simple fact.fair enough you can do it with a motorised mount if you deactivate the motor and do it manually but it kind of defeats the object as you may aswell just have a dob then yeah??

[YKSE]

Maybe I should put it more clearly since not everyone read the observation report section here, what I meant was about 20 new objects for each of the 3-4 hours session. that is about 150 new objects.

[Moonshane]

there's no doubt that a goto mount/scope would allow you to see more objects in one session (especially from a dark site) and keep them in view compared with a manual dob. personally, whilst I have a 'blow out' every now and again and try to see as many as I can in a night, I tend to take a more leisurely approach and am usually content with one new object each time out. I try and sketch what I see nowadays too which means you look at things a lot more intensely. it's not a race after all but thankfully there's enough room in the hobby for all types, scopes, methods and observing / imaging preferences.

[PeterCPC]

I can't speak about the technical differences as others have that sorted but I have had all those and have found the SCT by far the easiest to use and set up. Both Dob and Newt needed collimating virtually every time I used them. The SCT is very stable. It's GOTO is very good and saves a lot of time. Visually I could not see much difference.

Peter

[michael.h.f.wilkinson]

I have a motor on my Vixen GP mount, but it is only for tracking. At a recent star party on the roof of our university I picked up objects WAY quicker compared to both a GOTO Dob and some Meade ETX goto scopes, by using a big finder and the trick of releasing clutches, swooping to the right area, engaging the clutches, and fine tune position. By the time the goto scopes had been aligned I had found 5 objects. Having goto on an EQ mount does not mean you have to use it. I used Olly's TEC140 in a similar fashion. Works a treat. The key difference between Dob and SCT that made me go for the C8 is simply ease of transportation. I can set up my SCT with good enough polar align for visual in 5 minutes, and everything fitted into our old Peugeot 106 (with all camping gear as well) to take the scope with me on holidays. My C8 is great on all but the widest DSOs (current count >800, including 422 galaxies), scores well on planets and is a very good planetary imaging scope.

The key issue that makes me want to go for a big dob at some time is sheer aperture for a given price (although a C14 would be very nice too )

[crashtestdummy]

I can collimate a dob much quicker than most people can do 3 star alignment from what I've seen at viewing events with fellow nighthawks

My old 12" flextube took 5 mins to get out of the car,set up and collimate.the 16" lightbridge probably 10 mins but sweeping the sky doesn't involve any clutch unlocking,it's simple point and shoot.

[michael.h.f.wilkinson]

I can collimate a dob much quicker than most people can do 3 star alignment from what I've seen at viewing events with fellow nighthawks

My old 12" flextube took 5 mins to get out of the car,set up and collimate.the 16" lightbridge probably 10 mins but sweeping the sky doesn't involve any clutch unlocking,it's simple point and shoot.

Point, shoot, nudge, nudge, nudge (nudge-nudge, wink-wink)

Operating the clutch is flicking a handle through 90 deg, hardly an issue. If the mount is properly balanced, I do not need the clutches, but having the scope track objects (clutch engaged on the RA axis) makes for very relaxed viewing, especially for planetary. 

I also operated Olly's 20" Dob, and it is great fun, especially for those faint fuzzies, and when using UWA EPs.

[emadmoussa]

While I loved the tracking abilities of the NEQ6 and NEQ3, I often used the handset for steering...but goto...wasn't challenging enough.

I have to say it was fascinating to begin with then soon the novelty vanished. If I'm to get a motorized mount again, it'll be for the sake of tracking...meanwhile manual is all I enjoy.

[luminova11]

Why not have the best of both worlds. A dob with baseboard setting circles, a Wixey and an equatorial platform. Fully manual operation for star hopping, alt/az coordinates available and tracking. A good compromise I would have thought.

Sent from my LG-D802 using Tapatalk

[alan potts]

I bought an Sc for my first scope and it was rather a lot of money, it has a 3 meter focal length and fairly small FOV. The scope is OK but I think it was a lot of money for what I got, I then spent another 1000 plus putting it to where I thought it should be from new (2 inch system, balance, better finder etc).

I believe knowing what I know now I would get a top quality 18 inch Dobsonian with goto system from Sumerian and have a larger scope, yes it would have cost a bit more but what a scope. I am sure had I have been a member here then, that is what I would have done.

Alan.

[emadmoussa]

I think Sumerian Dobs are pretty expensive for what they are...their EQ platform is reasonably priced though.

If money is not an issue, I would get the 20" version of these... 

[YKSE]

We can easiy agree on that we have different scopes as our preferred scopes, the old simplied truth is:

Refractor = Best Performance per aperture

Reflector = Best Price per aperture

Catadioptic = Best portability per aperture

Since money is almost always an issue for most of us, the best we can do, is trying to find the best compromise we can accept, therefore we should be glad there are lots of choices to reasonable prices.

Choose carefully will usually save us hard-earned money, knowing what you want, what you give away is a good starting point.

[emadmoussa]

We can easiy agree on that we have different scopes as our preferred scopes, the old simplied truth is:

Refractor = Best Performance per aperture

Reflector = Best Price per aperture

Catadioptic = Best portability per aperture

Since money is almost always an issue for most of us, the best we can do, is trying to find the best compromise we can accept, therefore we should be glad there are lots of choices to reasonable prices.

Choose carefully will usually save us hard-earned money, knowing what you want, what you give away is a good starting point.

Well said!