Focla Length and Image Broghtness/Size

Hi,
I'd like to image the upcoming Moon/Jupiter occultation and I'm
trying to come up with a focal length that will give me a small
enough image scale to allow Jupiter and the curvature of the moon to
fit in the frame. The problem is that when I use a shorter focal
length (2000mm) Jupiter becomes so bright that it's basically just a
white hot spot. In fact I'd actually like to go even shorter on the
focal length to fit more of the moon in the frame, but that just
burns Jupiter out even more. 4000mm gives me a nice Jupiter, but it
is way to much for the moon.

Any suggestions on how to fit both objects nicely in the frame
without burning Jupiter out and without blowing up the size of the
moon too much? BTW I'm using a 1/4" CCD chip which increases image
scale to about the equivilant of using a 9mm eyepiece.

Thank you,
-Russ


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"RS" wrote in message
...

Any suggestions on how to fit both objects nicely in the frame
without burning Jupiter out and without blowing up the size of the
moon too much? BTW I'm using a 1/4" CCD chip which increases image
scale to about the equivilant of using a 9mm eyepiece.


I'd suggest stopping down your scope.

Jeroen.

On 06 Nov 2004 21:53:55 EST, RS wrote:

Hi,
I'd like to image the upcoming Moon/Jupiter occultation and I'm
trying to come up with a focal length that will give me a small
enough image scale to allow Jupiter and the curvature of the moon to
fit in the frame. The problem is that when I use a shorter focal
length (2000mm) Jupiter becomes so bright that it's basically just a
white hot spot. In fact I'd actually like to go even shorter on the
focal length to fit more of the moon in the frame, but that just
burns Jupiter out even more. 4000mm gives me a nice Jupiter, but it
is way to much for the moon.

Any suggestions on how to fit both objects nicely in the frame
without burning Jupiter out and without blowing up the size of the
moon too much? BTW I'm using a 1/4" CCD chip which increases image
scale to about the equivilant of using a 9mm eyepiece.

Thank you,
-Russ

Per unit area, Jupiter is brighter than the Moon. Frame the view you want,
expose for best detail on Jupiter, then enhance the Moon on your computer.

OR

Frame the desired view, make a series of exposures, half optimized for
Jupiter, the other half optimized for the Moon. Stack and enhance each
object seperately, then recombine to form the final print.

Cheers,
larry g.