The focus position of the SunDancer is pretty much the same as that of a 2" eyepiece if you use the 2" nose-piece cut into the TZ-unit. So you will usually not need extension tubes, but can simply plug the eyepiece into a 1 ¼“ or 2“ star diagonal. It is important that the telescope itself does not contain any plastic parts, but must be suitable for solar projection.
If you use a bino-viewer, the focuser must be moved inward a little further, but usually only about 1-2cm.
For photographic use, you only need extension tubes if you are working without a star diagonal. This straight configuration has the advantage that the image is not additionally mirrored and that the SunDancer is always protected from direct sunlight in the shade instead of being heated up on one side by the sun. Possible quality losses due to a star diagonal are thus also eliminated.
Please note that the quality of the star diagonal also plays an important role for the contrast in H-alpha. In our tests we have found that our hard-silver-coated BBHS mirrors provide the best H-alpha contrast. Compared to prisms, mirrors have the advantage that the light does not pass through a glass body which it can heat up.