SW 200/250 dob

[ObscuredbyClouds]

Can someone tell me how these two solid tube dobs compare with one-another pls ?

Am now in the throws of 8 or 10

Is the 10 worth that extramoney or does the 8 chuck its weight ?

Purley for visual of course

[jimmyjamjoejoe]

The 8 chucks its weight, it isnt the nations most popular scope for no reason.

The difference in views wont be dramatically different, at least not until you have a fair amount of experience, and even then it isnt shocking.

That said, i'd recommend getting the largest you can accommodate in terms of space, transport, and budget.

If 10 is your absolute limit then go for that, but if you intend to upgrade further down the line to 12 or above then just go with the 8 for now.

[Eastridge]

The only thing I would say having had the same chioce and having gone for the 10" is to be aware of the f ratio - it is a fast scope ( mine f4.7) and so subject to distortions ( called coma or astigmatism) at the egde of wide FOV lenses unless you spend a lot of money on lenses.

e.g. I am looking for a wide DSO lens but research tells me anything under £200 'suffers' in this way.

I think the 8" is quite a bit slower ( SW is f5.9) and not so prone to suffer.

I see people who are happily able to just ignore such issues & then others who then spend £100+ on coma correctors etc. but still have astigmatism.

Right now I do not think if I had my time again I would change my choice, but I do wish I had understood this as a factor before making my decision.

[ObscuredbyClouds]

Thanks for the replys, mind is made up and i think ill stick with the 8

[Tinker1947]

Its always been said the more light the better, so the 40% or so that the 10" gives would be nice, and don't be to put off by the F4.7 most of the error this will show you won't see, my 10" i quiet often use the stars on the out edge of the FOV to focus on and i don't notice any difference for the stars in the center of the FOV, my next upgrade is going to be a 16" dob with tracking, and i will stick with my present EP set-up.

[estwing]

if you get a 8 you'll wish for a 10 if you get a 12 you'll wish for a 16..and on it goes it's called A.F.....

[Kevin C]

I personally find the 8" dob no problem to move around and setup (I keep mine stored in an upstairs spare room) - I haven't tried to carry a 10" but I bet it's quite a bit bigger and heavier, so bear this in mind when choosing.

[ObscuredbyClouds]

This review is on FLO website, can someone shed some light on these two lines please

Its limiting magnitude in practice is around 14.2!

The low F ratio does mean that you have to choose your eyepieces carefully to avoid the seagulls effect at the edge of the field.

Regarding the latter, would say a BST or Planetry11 be any good or not?

[swamp thing]

Hi

These two scopes both offer excellent Views of the night sky.

For lunar and planetary observing there is very little difference in the views through either. It's only really on deep sky where the extra aperture provided by the 10" is noticeable.

The point about eyepieces is worth noting, as the 10" will indeed be more demanding. Whether or not that will bother you only you can tell.

Most Astro societies have open viewing evenings it would pay you to go along and have a look through a few scopes, chances are they'll be someone there with a 10" or an 8" scope you can look through.

[brianw1]

Its limiting magnitude in practice is around 14.2!

From my understanding, objects in the sky are measured by the brightness. This brightness is called magnitude. The higher the magnitude, the dimmer the object.

For example, the sun has a magnitude of -27 which is extremely bright, and a full moon has a magnitude of -13 which is also very bright. But for dim objects like galaxies and clusters, their brightness can be very low, and this telescope can see magnitudes of up to 14.2 which is sufficient.

[ObscuredbyClouds]

From my understanding, objects in the sky are measured by the brightness. This brightness is called magnitude. The higher the magnitude, the dimmer the object.

For example, the sun has a magnitude of -27 which is extremely bright, and a full moon has a magnitude of -13 which is also very bright. But for dim objects like galaxies and clusters, their brightness can be very low, and this telescope can see magnitudes of up to 14.2 which is sufficient.

I see said the blind man, thanks for that