Quote:
Originally Posted by Retrograde
Hi Joe - thanks for telling us about your eclipse setup. I also use a Pentax K-5 (aps-c)
The flip-mirror idea sounds really good and something I'll certainly investigate although I'm a little unsure how to go about getting a camera and eyepiece parfocal via this arrangement.
|
Sorry I didn't explain that. The camera needs more back focus than the eyepiece. The William Optic M70 refractor's Crayford focuser has a mm scale on the barrel. I focussed the camera, took a reading, then the eyepiece then I machined my own custom extender for the eyepiece. I machined it a little short then I focus the camera, pull the eyepiece up until focused and then lock it in place for the duration. If your refractor doesn't have a scale, use a vernier caliper to make the measurements.
One more thing, With the eyepiece, flip mirror and camera on the back, it doesn't balance on the dovetail foot. However the foot can be removed and rotated 180 degrees which extends the dovetail backwards towards the camera. This reversed foot also works when I use a 2 inch diagonal and eyepieces for visual.
For travel, I prefer the M70. It fits in my carry on camera back pack with all my other camera gear and the shorter tube sits with less vibration on the small mounts I travel with. The ED80 had to travel in my checked luggage. One day in Shanghai, I watched the luggage handlers throwing my suitcase up to the luggage hold, they missed and it fell down to the tarmac. ED80 was ok. Good suitcase and padding.
They are both nice scopes. If I were recommending a car portable instrument, the ED80 would be my pick but you will want to upgrade the focuser. I got both brand new some years ago for around $500 each so I've kept them both. Use the ED80 for lunar and annular and general grab and go scope and the WO for total eclipse travel.
cheers
Joe