Mike Jones and me have been sending a few mails back and forth last couple of days about a 64mm and 96mm eyepiece with an AFOV of 45 degrees. Why these characteristics: because it would be a nice extention to the already great Brandon line of eyepieces.
Currently Mike has designed a 64mm only and a 96mm is underway. This 64mm is more or less a asymmetric Erfle/Super-Plossl and the design is optimized for a 200mm f/15 Rumak. The latter can be found in Telescope Optics Evaluation and Design. Alas it does not use of the shelf optics. To get the best quality, a custom design is neccesary to use custom optics.
Another thingy of these eyepieces is that they have a huge fieldstop. It will not work in any conventional 2" focuser but a 3" focuser is the minimum. Personally, I intent to use a modified version of the Zeiss ring bajonet. At the moment I have no commercial plans with these eyepieces. However, if people are interested in these eyepieces, let me know, I might be willing to reconsider making a very small batch of these. To do this, at least five, preferably ten people should be willing to have these.
Below the Zemax data can be found. Underneath the Zemax data you can see a preliminary CAD-design of the same eyepice.