Re: Dobsonian Aperature Question

"MrWizer" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> I am trying to decide between two dobs (a 10" and a 12"). Aside from any
> considerations of size, weight, etc, how much of a difference will 2"
make.
> Will the extra two inches make enough of a difference to justify the cost?
> How much of a performance boost would I expect to see? Thanks for any
help.
>
> MrWizer
>
>

We have a 10" f/5.6 dob which provides very nice views, and with a dark sky
the spiral structure of M51 is just detectable.  M33 shows some mottling,
but no spiral.  I would find the 12" compelling if it clearly showed spiral
on either or both of these.  Unfortunately, I don't know the answer to this,
but I would bet it doesn't.  If the 12" doesn't, then I would get the 10"
and dream about a 15", which I know does the job.

Dennis