On Wed, 12 Jan 2005 11:16:54 -0000, "Robert Geake"
wrote:

Down to more light sensitivity at the end of the day. A 200mm f4 lens
will be a faster system than a 1000m f/9 telescope.

A big difference can also be seen between the run of mill cheapskate
lenses (of which mine are) that only go down to f/4 or f/5.6 and the
'holy-cow - how much!' lenses that go down to f/2.0 or f/2.8.

Of course, you trade off image scale as you switch to the camera
lenses but, unless you are aiming to pick up coma detail (and there
doesn't seem to be a lot of this with Machholz), stick with the wider
angle shots and try to get a nice shot that captures the tail(s).

Now I've got to figure out what to sell to get me a better imaging
system! My soul by the looks of it

Ill be one of the lucky ones that inherited holy-cow style 200 and
300mm lenses that go down to F2.8. They can suffer from seagull
stars though when i use the lowest F ratio!!

Hmm - I'm not sure if the "holy cow" lenses have that feature Rob ;-)

Why not sell your practically constan clear skies???
Ill give you £5 an hour

You're on. £5/hr x say 8hrs per night for 365 days a year = £14,600.
Do you want to pay in advance. I've already submitted an order for a
large format CCD camera on the back of this.

--
Pete
http://www.digitalsky.org.uk