Jupiter

Got up early on Tues. to look at Jupiter. It was about 45 deg high in the
south, and seeing was average (3/5). However, it was so bright that it
almost "hurt" to view in my F4.7 newt. Not quite as bad as looking at the
moon without a filter, but close. I tried a few colored filters, but none
seemed to help. They either made it too dark or lowered the contrast.

What do folks use to dim the brightness of Jupiter? Maybe I need a
polarizer? Thanks.

-John

On Wed, 8 Feb 2006 09:20:27 -0600, John Banister wrote:

Got up early on Tues. to look at Jupiter. It was about 45 deg high in the
south, and seeing was average (3/5). However, it was so bright that it
almost "hurt" to view in my F4.7 newt. Not quite as bad as looking at the
moon without a filter, but close. I tried a few colored filters, but none
seemed to help. They either made it too dark or lowered the contrast.

What do folks use to dim the brightness of Jupiter? Maybe I need a
polarizer? Thanks.

-John



Try a neutral density filter. One source would be www.telescope.com


--
Martin R. Howell
"The Astro Post"
www.theastropost.com

John Banister wrote:
Got up early on Tues. to look at Jupiter. It was about 45 deg high in the
south, and seeing was average (3/5). However, it was so bright that it
almost "hurt" to view in my F4.7 newt. Not quite as bad as looking at the
moon without a filter, but close. I tried a few colored filters, but none
seemed to help. They either made it too dark or lowered the contrast.

What do folks use to dim the brightness of Jupiter? Maybe I need a
polarizer? Thanks.

-John



As someone else pointed out, you can use a ND filter if brightness is a
concern.

Also - a filter I find helps bring out detail on Jupiter is an FLD.

Try an aperture mask. This also often helps on nights with relatively poor
seeing. It also works well on any bright object, except the Sun of course.
Just cut a piece of relatively thick cardboard and put a hole in it. Try
different sized holes, but I would not go smaller than one to two inches.

--- Dave
--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"John Banister" wrote in message
...
Got up early on Tues. to look at Jupiter. It was about 45 deg high in the
south, and seeing was average (3/5). However, it was so bright that it almost
"hurt" to view in my F4.7 newt. Not quite as bad as looking at the moon
without a filter, but close. I tried a few colored filters, but none seemed
to help. They either made it too dark or lowered the contrast.

What do folks use to dim the brightness of Jupiter? Maybe I need a polarizer?
Thanks.

-John

David Nakamoto wrote:
Try an aperture mask. This also often helps on nights with relatively poor
seeing. It also works well on any bright object, except the Sun of course.
Just cut a piece of relatively thick cardboard and put a hole in it. Try
different sized holes, but I would not go smaller than one to two inches.

--- Dave

Would an aperture mask that cuts light out of the center of the aperture
work (think bigger central obstruction), but still maintain the
resolution of a big scope?

Shawn

Shawn wrote:
Would an aperture mask that cuts light out of the center of the aperture
work (think bigger central obstruction), but still maintain the
resolution of a big scope?

No. In fact, that would probably combine the worst of both worlds.
You have just about all of the effects of the decoherence as a result
of turbulence, and get to add in all the usual effects of a central
obstruction. I wouldn't recommend it.

--
Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.html

I usually use more power, until the planet nearly fills the fov.
Last fall, watching Mars, I actually put on some sunglasses
(polarized).
Seemed to work fine.
But if seeing will support it, you can "dim" the image by crankin' up
the power.
Regards,
Uncle Bob