Posts Made By: Alex McConahay

You need to hang around with some people who can guide you. Get to a star party. Just announce where you live. Somebody will find you and tell you where you can meet other observers.

Alex

Lots of things to say, here, Joe.

The motofocus is a step forward, but will not get you all the way you want to go. The Motofocus attaches to your regular focuser knob, and just replaces your hand. This is great because you no longer have to get up and touch your scope when focusing (and thus shake it). But it is a DC motor and controller. It is hard to get an exact focuser position by the very nature of dc electronics. Also, you stil get mirror shift, and backlash problems. On the other hand, it is easy to use, and you will find you do not really need to remove it (in short they work well enough that you do not need "manual" focusing). But if you choose to remove it, it is fairly simple. It can be controlled from a computer, and interfaces with various automated focusing programs.

An additional focuser on the back of your SCT would help with fine focusing and astrophotography. You would do a rough focus with the C9.25 existing focuser, then refine it with the fine focuser. Therefore, you would not have to worry about the flat spot in the current focuser. This arrangement also overcomes much of the mirror shift and much of the backlash issues one gets when using a standard SCT focuser. (Not all of them!)

And of course, you could put a motor on your auxiliary focuser. Therefore you could use your main SCT focuser to do a rough focus, and your auxiliary focuser with the motor do do the fine, hands-free focusing (again, interfacing to computer automation).

One other thing to think about. There are two general types of motors running focusers. One is dc, the other stepper. Both are very good, but the stepper generally moves in very specific amounts with each pulse. Therefore, your focus position is more precise.

Hope this helps.

Alex

It depends on what you want to use the reticle for. To guide you want higher power. To locate and frame, you want lower. To just Polar align, you want probably higher power.

However, a Barlow can give you lots of flexibility here. Remember for most things that you use a reticle eyepeice for, you do not need the highest quality optically.

Alex

John,

What is your field of view with that scope/eyepiece combination?

You may have too much power with that focal length. The NAM is pretty large.

Alex

I know there are several systems based exactly on that. The Meade LPI I used to use did it. I think one of the SBIG systems do it. Basically, you are looking for a video system (LPI, ST-V (?), or webcam) instead of a still system (like DSLR or CCD). Then the video frams are stacked.

Alex

I would suggest you do nothing until you have given it a try. Put in your camera, and put in your eyepieces, and see what happens. If you have lots of focuser travel, and things are positioned just right--maybe you need nothing.

If you cannot get the camera to focus when the eyepieces can, then you need to consider changing things around. But before going down that path, figure out if you are happy with the focuser--you may want an upgraded focuser, which is of different height. Get the focuser and run the tests again before changing the mirror. (Same goes for any para-corr, or field flattener, or whatever you plan to use for astrophotography.)

For all I know, there are two sets of primary mirror mounting holes (There were in my Starfinder.) Neither set of holes would allow me to get to focus both visually and photographically. SO, I drilled one in between and it seems to work.

Good luck.

Alex

There's been a bunch of ads posted.

Alex

John,

Thanks for the good references.

The reason I am looking for a lager chart showing a constellation's worth or so is that it kinda helps me plan the sequence of the observing. WIth just lists, you have to arrange them in some order (like by NGC number or RA or Dec). This may get you bouncing from one part of the sky to another. (In a typical RA order, for instance, you could have two objects that are half a degree apart in the sky, but in between them on the list is an object separated by five degrees north or south, but which happens to have a RA in between the two.) I suppose I could figure it all out at the scope that night, but I prefer to plan before I go.

Is there something for the Herschel 400 similar to the Messier Marathon guides that tell you what order to search? If not, then the next best guide would be a star chart with all of them marked and highlighted. (Yes, I promise not to try to get it all done in one night!)

Alex

Thanks for the suggestions, everybody.

I think it looks like what I am going to have to do is use Cartes du Ciel (that I know you can add telrad targets and notes to) and make up my own star charts if I want to do what I am asking. I do not think I can do the same with The Sky 5, my workhorse planetarium program.

Alex

Thanks for the suggestions, everybody.

I think it looks like what I am going to have to do is use Cartes du Ciel (that I know you can add telrad targets and notes to) and make up my own star charts if I want to do what I am asking. I do not think I can do the same with The Sky 5, my workhorse planetarium program.

Alex