Audii Dudii, the conversion looks great... Just wondering how you change the aperture of the Contax 645 lens? Are you presetting it somehow?
Yes, for the moment, I'm using the lenses preset. Although it's slightly clumsy, for the type of photography I primarily do -- long-exposure, nighttime stuff on a tripod -- it's a very workable method (especially since most of the lenses are a bit on the slow side, so opening up them up to compose and focus doesn't admit as much additional light as a faster lens does, thus reducing the benefits of doing so) and I used these lenses on my A7r for more than a year with considerable success.
However, one way or another, I ultimately intend to control the electronic apertures remotely, while the lenses are still mounted on the Toyo. To this end, I used a Contax 645 26mm auto extension tube to provide the lens mount (and since this photo was taken, I have subsequently shortened it a few mm to reduce its thickness to 11.5 mm):
I specifically used the 26mm version, because it's identical to the 13mm version, except that it adds a 13mm spacer between the camera body and lens mounts, plus it uses wires to connect the pins on both sides, whereas the 13mm version connects the pins together via a circuit board, which is much more difficult to hack. (The 52mm version is identical to the 26mm version, except it uses a thicker spacer and longer wires.)
I am still waiting on the connectors I ordered from China via eBay, but my plan is to either attach them to a remote Contax body (via the camera body mount on other side of the auto extension tube that was left over when I salvaged the lens mount side) or to adapt a Fringer adapter to serve the same purpose. Of the two, the remote camera body approach will be easier, because unlike the Kipon adapter for the Contax N lenses, which uses ribbon cables to connect the pins on both sides to the central circuit board (thus making it easy to hack), the Fringer adapter, similar to the 13mm auto extension tube, connects the pins directly to the central circuit board (making it more difficult to hack.)
I'm still undecided at this point as to which method I will use, but just in case, to make more room between the two standards should I decide to go with the Fringer adapter approach (I have on sitting next to my keyboard as I type this!), I recently redid the lens board using the scarce, 24.9mm recessed board Toyo once offered instead of the 12.5mm recessed board that is currently available. Recessing the lens by an additional 12.4mm requires the standards to spread further apart by a corresponding amount, creating more room inside the bellows to hold the guts of the Fringer adapter, should I decide to go this way. (In theory, this will also make it possible to autofocus the lenses ... imagine that: A view camera with autofocus lenses!)
FYI, I am also planning to use at least the Contax N 17-35/f2.8 zoom on this camera, because I prefer a wider perspective to a longer one and I rarely use any lens longer than 55mm. The image circle this lens projects is surprisingly large (there's only a few mm available for movements at 17mm, but by 21mm, the image circle has grown considerably, and by 35mm, it almost covers a 6x6 cm frame!)
Contax N 17-35/f2.8 zoom image circle at 21mm:
Contax N 17-5/f2.8 zoom image circle at 35mm:
Note: The grid lines are 10mm apart, so you can see there is significant coverage available at these focal lengths and every one in between them. The image quality seems to be pretty good, too, although there is sometimes noticeable smearing in the corners at 17mm (which the Kolari thin-filter mod goes a long way toward eliminating, btw) but that largely disappears by 19-20mm and as you can see, any magenta-green color shifts are minimal as well. That said, don't read too much into IQ with regard to these photos, because I free-lensed them, holding the back of the lens against a flat lens board. As such, the focus plane may not have been perfectly parallel to the sensor.
Using this lens with movements is the primary reason I built this camera -- it has been a favorite of mine, distortions and all, since I bought it more than a decade ago -- and being able to use my Contax 645 lenses as well is just a nice bonus. Unfortunately, bringing the two standards together close enough to focus it at infinity (the Contax N lens flange-to-sensor distance is 48mm versus 64mm for the Contax 645 lenses) will make it difficult to stuff the guts of the Fringer adapter inside the bellows between them, so I will probably use the guts of the Kipon adapter instead -- Yes, I have one of these sitting next to my keyboard as well -- should I decide against using an external body.
I'm fairly certain I answered your question somewhere above, but if not (or you have any more questions), feel free to send me a PM.
P.S.: I dropped my A7r body earlier today and now it doesn't work. This makes not one, but
two broken A7r bodies I now own, and with my annual insurance premiums and property tax bills coming due in September and October, respectively, it will be several months yet before I am comfortable spending money to buy a replacement or have this latest broken one repaired, if possible. In the meantime, I'm going to use my Fuji X-Pro 1 -- it's just collecting dust otherwise and something is better than nothing, eh? -- and have started work on the adapter / mounting plate for it this afternoon. Because of its 1.5X crop factor, my 645 lenses will now be too long for my taste and preference, so I'm going to focus my attention on the Contax N 17-35/f2.8 for now, as I expect to be able to get by with its effective focal length of 25-52mm. On the positive side, the amount of movement available from this lens just increased significantly! (sigh)