Is it possible to achieve back focus by stacking a field flattener, JMI Focuser NGFS, and ST-7E on the back of a Meade 10” LX200?
Probably. That's not a lot of detail to go on, so let me share my experience. The ST-7E requires about .92 inches of back focus. (e.g. distance from top of sensor to the front of the camera). The LX200 has lots of back focus, until you add a flattener/focal reducer into the mix. If it's a classic LX200 10" f/10 with the Meade f/6.3 flattener focal reducer, it will probably work fine. The Meade f/3.3 focal reducer will likely be a problem, there just isn't much room between the back of it and the where the sensor has to be. There's are at least two versions of this reducer, and one is worse than the other. I switched to a Moonlight focuser on my 12" f/10 LX200 because the reducer can be threaded inside the focuser draw tube, and so keep the sensor closer to the reducer. This is one of those "you have to try it" situations.
