GenEOS wrote:
Ken, my scope is a Meade LTX-125.
Do you mean the ETX-125? Couldn't recall Meade has a LTX series.
I have a ETX-90, which I used as a quick-view scope and the occasional shot of the moon, but have long given up hope trying to use it for eyepiece projection astrophoto. It's just not stable enough.
On it the eyepiece mounts in the vertical.
The 1.25" will bottom out in the socket and the screw just keeps it from comming out. This is way more stable than using the t-mount on it.
But by the time you've put the scope on a equatorial wedge( highly desirable for to maintain your sanity while trying to track and focus, and to prevent field rotation) the eyepiece port will likely to be tilted at some angle other than vertical.
Since the eyepiece projection tube is coupled to the eyepiece port with one lock screw only, there is some play around the axis of the screw. You can test this by insert an eyepiece into the port and tightening the lock screw as much as possible, then try to wiggle the eyepiece perpendicular to the axis of the screw. Any play is too much play when you attach the eyepiece projection tube and the camera.
Plus you can use various eye pieces in it. I have a tele-vue 8mm that has a very large eye relief, it should work great.
I am doing some research and then purchase if it is getting good reviews...
For planetary work you don't need a large eye relief. Say Venus now is ~60", at a focal length of 1900 mm the image height at prime focus is only 0.55 mm. What are needed are good chromatic correction and orthoscopic, oh and avoid using eyepiece with built-in barlow (TC in camera talk) as these types tend to produce more flare.
Ken