A 135 format diagonal (24mm x 36mm) is 43.27mm. I’ve been saying “larger image circles” compared to image circles associated with mirrorless / DSLR lenses, which are usually no bigger than the diagonal of the medium. Rodenstock usually refers to their digital lenses with an “HR”, so I often abbreviate Rodenstock to “Rodi” or simply “32hr” for the Rodenstock f/4 32mm HR-W. Schneider Kreuznach Apo-Digitar lenses are SK or sk. I use various, somewhat random abbreviations for lens names. Schneider -Kreuznach / Alpa 12 / IQ41450. A few degrees of back tilt was applied to render all the duckweed, cattails and grasses sharp from front to back in a single image, while adjusting the size and position of the cattails vs grasses. Most of these lenses handle that amount of shift except for a few of the wider Schneiders (sk28 and sk35). In “FF” equivalents, the 60mm becomes a 29-39mm mini-zoom the 90hr-sw becomes a 44-58mm zoom (in FF equivalents). For example, with the sk60xl and the back in the portrait orientation, shifting left/right ~15.5mm gives you a 54×72, 4:3 stitched image. Don’t forget that you can do two-image stitches by shifting the back. Or if you have a favorite focal length, pick that and gap up/down from there. On forums, you will often hear, “Pick the widest lens you want then gap up from there.” That’s a reasonable approach. Also applying back tilt to adjust the relative size of objects in the scene. Tilt: Apply lens tilt to adjust the plane of focus angle, which creates a depth of field wedge that keeps subjects at various distances from the sensor plane in sharp focus.It also allows you to shift the back in its portrait dimension in order to increase the angle of view by making use of the larger image circle. This is a simple and reliable way to create a panorama, and is something I do very frequently. Most of the time this is done in order stitch two images together. Shifting Left/Right: Usually accomplished by sliding the back left/right.In general, this is done to keep the back and lens perpendicular to the ground but there are many other applications. Rise/fall: shifting the lens and/or the back up/down to frame the scene without tilting the camera.All of these will be covered in greater detail in subsequent articles: There are three primary movement applications used with technical cameras. Navigating Lens ChoicesĪ primary benefit of using a technical camera is to apply movements and utilize the larger image circle associated with most of the dedicated lenses from Rodenstock and Schneider. Schneider Kreuznach 60xl / Alpa STC / IQ3100. Field Techniques for Technical Cameras – Lenses and Accessories Sepia Sunrise Auburn, Ohio.
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