Question for a friend

[Ray Brooks]

A friend has been questioning me about what he needs to start working a bit with astrophotography. He is an accomplished photographer but has not dealt with astro.

After discussing his plans with Astronomics, they recommended the Celestron C5S-GT. Germ Eq mount 5" SCT as opposed to the Meade ETX-125AT. The recommendation was primarily due to stronger motor to handle his Canon 1D , f/10 SCT instead of f/15 Mak, and more available for visual back (OAG, eye piece projection, etc.) The recommendations sounds good to me but what can you experienced guys tell us that he didn't?

Thanks,
Ray Brooks

[Jean-Yves]

Hi Ray,

I can comment on the ETX125 :

I have a Meade ETX125 and it is good visually and for webcam imaging.
I imaged the Venus transit with it and a Canon 300D : for 1 sec exposure it is OK but for longer exposure astrophotography I agree that it would not be a good platform for the Canon 1D.
It is a bit weak and the camera's body does not go between the arms.

I cannot comment on the celestron but I am sure someone will jump here with a good advise for your friend,

Cheers

Jean-Yves

[twilbur]

The big questions for a new purchase go something like this:
Is a goto mount required?
What imaging targets? Planets / high magnification solar system stuff, wide field DSO work, or a compromise of both?
Will the scope have to travel to a dark site, or used in the backyard?
How big is the budget?

I assume he needs a goto mount and wants to do DSOs with the film camera. I have no experience with either scope mentioned, but I suspect that neither of the mounts will provide adequate tracking for long exposures. However, the reasons provided for choosing the C5 make sense. Getting the focal length as low as possible is a good goal in this case. A C5 with a focal reducer would get him started.

If he's got more money to spend (say $4000), and doesn't need to travel with it, a used LX200 and a short apo refractor would give him goto, good tracking, a wide FOV and a nice forgiving image scale.

[Ray Brooks]

Thanks Jean-Yves and Ted.

I also believe the camera will mount better on the SCT with the German equatorial mount. The 10D is rather large. He also has a 1D he could use as well as other film cameras.
The targets of primary interest is not certain at this time but he wants to start with eyepiece projection on planets and the moon.
Portability is important. He doesn't really want to go any larger than a 5" at this time.
A GO TO is important as he has little astronomy experience. I've never owned a GO TO scope. Even after many years of experience, I get frustrated using small setting circles.
I don't know what his budget is on this, but I know he doesn't want to drop $4000 on a less portable setup until he is sure this is something he really wants to get into. I have a 15 year old Meade Premier 2120 10" SCT on the LX6 drive with digital setting circles and CAT computer. I know it gets old setting up this monster and taking it back down. Of course, Meade says it's portable.
He doesn't mind dropping $1300-$1400 on the scope and accessories to experiment, but the big scope will have to wait.
Any other thoughts on this?

Thanks again.
Ray

[Jean-Yves]

Ray,

I have seen beautifl images taken with the Meade LX90 .

On Astromart, there are some good deals I believe, such as http://www.astromart.com/classifieds/details.asp?classified_id=281967
I do not know the person, but that's the kind of deal available in Astromart.

I'll let LX90 owners jump in here ...

Cheers

Jean-Yves

[sc02492]

I'm coming into this thread late.  Sounds to me like your friend's goals,  budget, and experience level are consistent with doing two types of astrophotography:  planets/moon (afocal, eyepiece projection, prime focus), and piggyback deep sky.  For planets and the moon, you don't need to be polar aligned, and you don't need a fast scope.  Piggyback astrophotography of DSOs can be very satisfying and requires "reasonable" polar alignment and tracking for short exposures, but is quite forgiving.   BUT- any meaningful attempt at "prime focus" deep sky photography will be more difficult on the budget that you describe, since you would need a more expensive mount that can track accurately.

Based on these considerations, and restrained by the budget, my vote would be for the Meade ETX 125.  The higher f ratio will be great for planetary detail and lunar shots.  Also, it's an easy- to-learn, GOTO fork-mounted scope, which is a bit more intuitive than a GEM and will not have certain problems like meridian flip.  It's very portable, and with the deluxe tripod it can be polar aligned easily for piggyback deepsky shots.  I don't anticipate that the weight of the 10D should be a problem.  The only downside of the fork-mount is the occasional problem with camera clearance for objects near the zenith, but he/she could plan accordingly.

You might try posting your question on Mike Weasners ETX site as well- lots of useful information there.

Steve

[Ray Brooks]

Thanks Steve.
I glad you like the ETX since I just got my new ETX-125AT from UPS today. I think my friend is still going with the Celestron.
There is one reason I would be reluctant to recommend the ETX to him. I have read all of Doc Clay's documentation about problems with the ETX and what needs to be done to correct them. I don't have a problem with that and have emailed Doc about a Supercharge appointment (awaiting reply). I'd hate to recommend a scope to someone and then tell them that now they need to fix all these things to make it work right. I bought my ETX for casual observation. I have a bad back and setting up the 10" SCT is rather tiresome.
I'm hoping he will have good luck with the Celestron German equatorial mount right out of the box. Although f/15 is better for lunar/planetary work, I figured f/10 would be ok and he can use a f/6.3 reducer/corrector if he wants to go deep.
Can you put an off-axis guider on the ETX? I know I had to buy a different t-adapter for my ETX-90, which I assume will work on my new 125. I never tried to use the OAG or reducer/corrector from my 10" Meade on the ETX-90. I'm guessing they won't fit, but they will fit the Celestron 5" SCT. That could be another benefit for the Celestron.

Thanks again, any other opinions are welcome.
Ray