new ding (haha, kinda like your name),
using a dslr with a field scope (or what you call monocular) you need an adaptor. in that case the scope will be turned to a tele lens equivalent, in the case of Swarovski, Nikon and Leica, etc., a 800mm. but the dslr loses autofocus function and the largest aperture greatly reduced. but some still opt for this setup maybe due to the instantaneous response of the dslr and rapid continuous burst of dslr.
using a dc with a field scope can have the eyepiece of the fieldscope on as well. e.g. using a 30x eyepiece will then give you 800 x 30 = 2400mm equivalent, which is way more powerful magnification. then you can add to that with the optical zoom of the dc. so the magnification provided by a fieldscope+dc combo is beyond comparison. it's also a lighter setup and there's no vibration due to the mirror flip of dslr so vibration in this setup is less of an issue considering the same focal length equivalent. but dc hunts when focusing and the response is generally slower.
i've seen ppl using a fieldscope + eyepiece + dslr with lens (e.g. 50mm) on or with extension tube as well. haven't tried it but it seems a very cumbersome setup and difficult to carry around in the field.
bryan
