Aside from the central beamsplitting prism, the Jentsch head for the AO series 10/20 used mirrors, as did the Seidentopf heads for the 100 series and the 400 series. The Jentsch head has a travelling telan lens, that compensates for the interpupillary change in tube length but it can easily be removed. It is a correcting part of the infinity system as well. The other two heads have just the correcting optic, which is easily removed and replaced with a window, if need be. The dovetail on them all is 2"( 50.4mm)
the series 10 Jenstch head is available pretty cheap, usually. The other two, not so much.
Here is one advertised as having clear optics, so it is returnable for a complete refund, if it doesn't. The # 176 eyepieces you won't likely need so you probably can get some of your money back for those. https://www.ebay.com/itm/American-Optic ... ctupt=true
Thank you, The head shown in the link is too heavy for telescope use. Something similar Zeiss/Leica heads shown in the Astromart ad can be easily modified by changing EP holder to 1.25” and adding a T2 bayonet at the scope side.
Does anyone know which model of Zeiss binocular head uses mirrors instead of prisms.
That head weighs 2 lbs. There is a T2 to 2" dovetail adapter for it......but
I didn't understand that you wanted to use 1.25" eyepieces. For sure that is best but finding an economical 30mm binocular head limits your choices quite a bit. Some of the Chinese scopes with 22mm fields use 30mm Seidentopf heads. I would guess mirrored for those, since mirrors are cheaper to do than multiple prisms. . There isn't the same incentive to keep the weight of a microscope head down as there would be if it was balanced on the end of a telescope.
However, the Zeiss head that you are showing does not look like it includes a deviating prism or deviating prism section, which would cut the weight down some. The deviating prism is necessary in microscopes to change the angle , so the head has a comfortable viewing angle. Some microscopes have the deviating prism in the microscope body itself, so the head contains only the beamsplitter prism and 2, 90degree sections. In many cases with seidentopf types, the beamsplitter to viewing tube section can be removed from the deviating prism section, with a few screws leaving a flange mount. Lomo made one with 30mm eyetubes separate from the deviating prism, with a dovetailed entry port that would easily convert to a T2. I think it has double eyetube focusers too. Those should be available fairly cheaply.