Hey Chris, how does one mount and shutter-sync those technical camera lenses to your A7r? Do you have an adapter that provides the full range of tilts and shifts (which I suppose would be the reason for using them)?
The 55mm Apo-Sironar, as an example, has a huge image circle...what would be the equivalent focal length on your camera?
Luke,
The focal length doesn't change anything, but the size of the sensor/film area DOES. The "wider" that sensor/film area(for any particular FL), the "wider" a lens will seem. Take for example a Schneider 150XL, which was designed to cover 8x10 film. A 150mm lens is VERY wide on 8x10, similar to a ~21-24mm lens' FOV on a 35mm camera system. But that same 150mm lens, when used on a 4x5 camera, will have a relatively "normal" FL representation, similar FOV to a 45-50mm lens on a 35mm camera. So Chris's 35XL will show the exact same FOV as a 35mm lens designed for a 35mm system, like Nikon or Canon. But the image circle on that 35XL will be VASTLY larger than the 35mm systems lens, since it's designed to cover MFD sized sensors, not just 24x36mm chips.
In terms of triggering the camera, assuming that one is using the central leaf shutter on the lens(and not the focal plane shutter in the body by itself to determine exposure duration), you could simply do the following operation:
1. Focus, while the leaf shutter is open.
2. Close leaf shutter.
3. Set shutter to desired aperture, shutter speed, etc.
4. Trigger camera to start an exposure in "Bulb"(or a desired preset exposure length, say 2-3sec?).
5. While the body's shutter is 'open'(but not recording any light due to the lens' shutter not being open), trigger the shutter on the lens, to allow the actual exposure to commence.
6. Shutter on lens closes/closed, end exposure on body.
It's a little more work than simply "push the button", but as you can see, it can be worth the extra effort.
However, if you want to use the internal shutter on the body to determine the exposure length, simply leave the lens's shutter OPEN(but set at the desired aperture for exposure), and shoot away, using the focal plane shutter to control the exposure length.
Versatile, and you get the "best of both worlds", IMO. Hi-end glass(some might say the best available to non-military or "unlimited budget" clientele
), two options for shutters, and the ability to perform movements/distortion control/manipulation with EVERY lens in ones kit. This is important for architectural photographers, or those who simply want utter control of framing, without introducing distortion/keystoning. Or simply for flat-plane(vs. spherical) multi-frame stitching.
-Dan
