digital photo's using eye piece projection question

I have a 5 year old Meade etx 90 go to scope and have had a great deal
of enjoyment using it. I'd like to take some photos of a few things
using a canon digital camera using eye piece projection.

I have a few questions,

1. what is the highest magnification eye piece that can be used with
this configuration?

2. should the eye pieces be the highest field of view possible?

3. Is there any software available that will allow me to sum multiple
photos into one photo that simulate long exposures?


Thanks any hints or tips welcome.

"Modat22" wrote in message
...
I have a 5 year old Meade etx 90 go to scope and have had a great deal
of enjoyment using it. I'd like to take some photos of a few things
using a canon digital camera using eye piece projection.

I have a few questions,

1. what is the highest magnification eye piece that can be used with
this configuration?

2. should the eye pieces be the highest field of view possible?

3. Is there any software available that will allow me to sum multiple
photos into one photo that simulate long exposures?


Thanks any hints or tips welcome.

'Lo Modat22 --

There are a few people who read this newsgroup
who are amateur astronomers and who can help
you with your questions. But because of the high
amount of "noise" here, they may not look in very
often. So you might try a different newsgroup...

sci.astro.amateur

I just looked in, and while it also seems to be a
bit noisy, there are probably more people reading
sci.astro.amateur who can answer your questions,
and who read and post there more often.

HTH

happy new-year days and...
starry starry nights!

--
Indelibly yours,
Paine

P.S. Thank YOU for reading!

P.P.S. (shh) Some secret sites...
http://painellsworth.net
http://savethechildren.org
http://home.secretsgolden.com

On Thu, 27 Dec 2007 14:38:13 GMT, "Painius"
wrote:

sci.astro.amateur


Thanks for the heads up.

Happy new year.

On Thu, 27 Dec 2007 13:58:38 +0000, Modat22 wrote:

I have a 5 year old Meade etx 90 go to scope and have had a great deal
of enjoyment using it. I'd like to take some photos of a few things
using a canon digital camera using eye piece projection.

I have a few questions,

1. what is the highest magnification eye piece that can be used with
this configuration?

2. should the eye pieces be the highest field of view possible?

3. Is there any software available that will allow me to sum multiple
photos into one photo that simulate long exposures?


Thanks any hints or tips welcome.

Since a maximum magnification for any aperture (ignoring atmospheric
distortion) is approx. 2 x aperture (in mm), you'd have a max of around
180 for the 90mm ETX. As magnification is derived by dividing OTA focal
length by eyepiece focal length [OTAfl / EPfl = mag], for the ETX that is
[1250 / x = 180, or 6.944444444] but in practice I found with mine that
the 9mm was excessive most of the time.

I would think that you'd pick an EP with a AFOV that matched what you
were trying to photograph...

There are a number of applications that are available, but the most
common (general purpose, as opposed to those sold specifically for astro
cameras) I've seen is Registax.

Meade has an excellent discussion of Power @ http://www.meade.com/support/
power.html