Re: 8" SCT v. 11" SCT

Bill:

Nice to see you here..

>>Actually a 10 or 12 inch DOB will have a much shorter focal length than > the C11 and use 2 inch eyepieces effectively at that focal length thus allowing for a significantly wider possible field of view.

>u have a citable source for this information of course ? Though it needs to be noted that your statement regarding the focal length of the Newtonian is superfluous information given the subject line. You did read that didn't you ?
-------

I guess if you need me to point out that the vast majority of
Newtonians are F6 and below.... My own 12.5 inch is F4.06 which with a
2 inch eyepiece is capable of a tad bit over 2 degree FOV.

As far as reading the subject line... Possible you have noticed that
myself and others have suggested to the original poster that other
options are available to him and that he ought to consider them before
making a purchase. My first scope too was an 8 inch SCT, I am
certainly glad I found other designs.

>>>Yet you choose to ignore the opposite of this. And that is that smaller DSO's will have a greater image scale than with a widefield instrument.
----

It is very difficult to increase the maximum possible field of view,
that is inharent in the scope. It is very easy to increase the
effective focal lengh or "image scale." That can be done for a few
dollars with a barlow.

>> In the other sense, the Newtonian could fit more DSOs in
> the eyepiece at any given moment due to that larger FOV.

>So can my naked eye .... but that's not the subject here. Your blatent bias towards Newtonians (actually Dobsonians) has skewed your reasoning
here.
--------

How many galaxies can you see in the Virgo Cluster with your naked
eye.....

I have no problem admitting that I enjoy DOBs. I also own two SCTs.
However the point here is not to play favorites, rather it is to help
the original poster make a choice that he can be happy with. By
letting him know what the advantages are of other designs, it just may
be that he will spend a bit of time investigating those choices.

I have no doubt that for many folks, the C-11 or the Nexstar 11 would
be a good choice and a scope they would be happy with.

I also know that this past summer, I shared the eyepiece of my 10 inch
DOB more than one owner of an 8 inch SCT that was very impressed when
viewing through a DOB, not only the optical performance but the ease of
use and the ease of setup.

Yes I like Newtonians and I like DOBs, but when someone is trying to
decide between an 8 inch DOB and a 12 inch DOB, I have no problem with
someone else suggesting they consider an SCT.

Let us all keep an open mind all the possibilities.

Best wishes and clear skies...

jon

.

Relevant Pages

  • Re: opinions on apogee 80mm optics
    ... >your son, a refractor is probably not the best way to go. ... >Newtonian OTAs at bargin prices, ... >smooth DOB mount. ...
    (sci.astro.amateur)
  • Re: Any Opinins On SkyQuest10?
    ... I have not seen one the Intelliscopes face to face, ... My guess is that setting up the 12 inch Hardin Optical Dob is not a great deal ... Still, an 8 inch F6 scope is a great balance between cost, ...
    (sci.astro.amateur)
  • Re: How come no high speed triplets?
    ... Costs lots of money and for visual use a Newtonian with a Paracorr can provide ... For a bit more one could get a custom 6 inch F4 newt which would operate at ...
    (sci.astro.amateur)
  • Re: Off-Axis (Zero Obstruction) Reflector Telescopes
    ... > an aperture mask is good but isn't as good as far as contrast/diffraction ... DGM 6.5 inch reflector I beleave comes down to optic surface ... high quality optic in there 16 inch Dob .with a high precision mirror ... for the best high power image possible from that particular scope. ...
    (sci.astro.amateur)
  • Re: Meade 8" Newtonian
    ... Another option is the Synta Orion 8 inch F5 Newtonian, ... Orion XT-8 Dob on my CG-5, ... The Meade 8 inch Starfinder DOB used a heavy cast iron mirror cell which ...
    (sci.astro.amateur)