From: Mark Gaffney <markgaffney@me.com>

Date: May 26, 2010 5:07:00 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Best planetary imaging camera

Milton, 

This Jupiter shot I`ve just posted is at prime focus with the C9.25. 

The corrector was always put back in it`s original position (I had pieces of sticky tape in position-cut in two around the rim to line it up) but the secondary was removed once, as I couldn`t budge the corrector without getting my finger behind the hole in it`s centre initially. 

The secondary was lined up again to the best of my ability using information from a link which I think you sent me..& collimation was attempted also using methods from one of these links...

My moon shots since this have been perfectly alright as far as I can tell but maybe things at a different focal length would give different results? 

If you look in my Mark`s Moon shots folder in the group`s Files section there is a Moon mosaic taken with the Scorpion for example...I`ve removed most of the other extraneous files months ago.

Mark.

On 27/05/2010, at 8:44 AM, Milton Aupperle wrote:

Mark;

On 26-May-10, at 4:10 PM, Mark Gaffney wrote:

> Hi Alan & Milton,
> Apart from some good results shooting the moon with my colour Flea 2
> I`ve been mostly disappointed with results from it with the planets.
> I`ve tried Saturn & Jupiter on 2 different nights with poor results-
> & not from want of actually trying hard to get the settings right
> when I have a planet in my sights...
> So far my best results with Jupiter have been with my DBK 21.

It's so small it's hard to tell if it's even in focus, let alone if
it's collimated.

> Would this be because of some inherant limitation of the chip on the
> Flea 2 in taking these subjects? (as mentioned below Milton, you say
> the ICX618 is most sensitive in certain spectra).

No - it's skill and solving all the other issues you've had. You have
to put in the time learning what constitutes good seeing, what is
sharp focus, what color balance is before you can produce good
images. You also need to have a mount that keeps the target centered
too.

Your Color Flea is 1.7 time as sensitive as a Color TIS camera is, as
it has 7.4 micron pixels versus 5.6 micron. So a color ICX618 will
have the same ability to gather light as the Color Flea.

> I posted some results with my B/W Scorpion 20SOM recently of Jupiter
> taken since my corrector & secondary was removed which seem to
> indicate that the collimation is in fact not too bad..I`ve attached
> a snapshot again below..

There is no such thing as "collimation is in fact not to bad". It's
either collimated perfectly or it isn't collimated. If it's off, or
the corrector plate isn't in the original position (after you "cleaned
it") then your going to get soft out of focus images all the time.

I've sent and posted links on Collimation in the past for you. You
can't do it at prime focus and you need good seeing too.

Milton Aupperle