|
Hi Rodney
I also have had a Meade 80mm ed apo f6 and over the past year have been using it with my Meade 400D DSLR. I find the optics are excellent for wide fovs with the 400D. You will get a bit of vignetting so use flat frame correction and of course dark frames.
A couple of small problems:
1. As my scope does not have a vernier on the Crayford focuser I found it a little severe to get fine focusing. So I clamped a 3in plastic jar lid on one of the 1 1/2 in knobs. This gives me an effective 2:1 "gearing" advantage and it is adequate for good focusing. With focusing I have found that using a Bahnitov mask on a bright alignment star provides excellent and quick focusing. I made my own by sizing the attached mask (designed for a sct but works fine on the refractor) outline on my printer to suit the 80mm, glueing the printout onto a thin piece of cardboard, cutting out using a sharp Stanley knife and then strengthening it with a thicker outer cardboard ring.
2. When you have focused properly you may be tempted to lock the focus with the locking screw. I have found that this moves the focuser
slightly off focus. I believe that this is a common problem with Crayford focusers (the cheaper ones I guess!).
3. If you are not going to use the lock then the movement of the focuser needs to be fairly stiff to prevent the Camera weight sliding it out of position. When I got my scope I found that this could not be done as the focuser movement could not be tightened to prevent movement by the camera. I got zero help from suppliers or Meade (send it back they said!). However, I soon found that there are a set of small Allen screws buried in the underside of the focuser and by careful adjustment of these I was able to fix the above problem.
4. I recently bought a Ritchen Chretien 200mm f8 scope to use the 400D on narrower fovs. However, I have had little chance to try it out because of the cloudy Sydney weather this summer. However, again I have found that the Bahtinov mask is ideal for quick and accurate focusing.
PS I do not consider my self an expert in the above matters but have come to them by just feeling my way! I hope they help you.
Cheers Peter
|