Achieving XPan with Micro Four-Thirds

The XPan system was panorama in the palms of your hands. You didn't have to take multiple photos or stitch; you only needed one exposure out of the camera, and you had a scenic, wide view.

A past blog post talks about the GFX system's 65:24 format crop mode, which is absolutely a nod to the 65x24mm panoramic negative size of the XPan system. It's plenty of fun, very different from using the full sensor of the GFX (or any camera, for that matter), and it does make for a convenient, single-exposure method to receive instant results. If the goal is more cinematic, snapshot-adjacent images (a la street photography or behind-the-scenes candids), this crop mode is the best way to achieve it.

The beauty of the XPan system was that it supported two formats: both the 65:24 panoramic as well as the standard 24:36 frame. Using the GFX's crop mode, it should be noted that you're losing lots of information and resolution. When using the 65:24 format on our GFX 50S, our 50-megapixel images are reduced to 25 megapixels. If the goal is to capture the native frame, as well as a wider-format image, the GFX's 65:24 mode doesn't quite carry the same spirit.

Stitching using multiple images allows for the use of the camera's full sensor, though the images needed to be stitched together in post production. Overlapping elements of the images allow for stitching software to detect where the images couple, and the results net images that well exceed the native resolution of the camera.

Fotodiox has a wide variety of adapters that can be used for stitching, from as complex as our 4x5 or RhinoCam adapters, to more rudimentary designs like the TLT ROKR tilt/shift adapters or the Shift line of adapters.

The Challenges

I wanted to focus on the Shift adapters. On paper, it's the least complicated to work with. I was most interested in revisiting the adapters we had for the Micro Four-Thirds system, mostly since it wouldn't personally be my first choice when stitching images. While I understand that a Micro Four-Thirds sensors can't provide the full 65x24mm image, I wondered if we get get a stitched image wide enough to hit the 65:24 ratio, at least.

The innate crop factor of the Micro Four-Thirds can be quite limiting as well. A whole 2x magnification can be detrimental, and to work against that, we had to choose the widest lens available to us, which was our Carl Zeiss Distagon  [T*] 40mm F/4 C for the Hasselblad V system. This still nets a 80mm full-frame equivalent focal length, but we'll also have a wider field of view thanks to the stitching.

I like our newer shift adapters for the medium format lenses to mirrorless cameras, since they have a built-in tripod foot, but this line didn't include Micro Four-Thirds. To use our Hasselblad lens on our Micro Four-Thirds camera, I used two adapters together: HBV-EF-P and EF-MFT-SHT.

Lastly, the stitching process requires multiple exposures. One constant issue is keeping any movement in the scene to a minimum. That's about as feasible as asking the wind to stop blowing, but we'll do what we can.

The Results

After stitching some of the images together, I was pleased to find out that there was enough information for an XPan-format image. To my surprise, there was actually a little extra on the sides, too.

Regarding the camera's crop factor, the benefit of stitching is that we get some area back in the final image. The resulting XPan stitch had a 37.71mm diagonal, which is quite the improvement from the native 21.64mm diagonal of a Micro Four-Thirds system. It doesn't quite get as large as full-frame, but we end up with a 1.15x crop factor, instead of 2x. In our XPan stitch, the 40mm lens is more like a 46mm lens.

One other benefit of stitching is the extra resolution. We shot our images on the GH4, which has a 16 megapixel sensor. After cropping out the excess from the sides, our stitched 65:24 image from the GH4 had pixel dimensions of 9406 x 3473, which ends up calculating to 32.6 megapixels. That's twice the resolution of a singular image and the cherry on top is that it surpasses the resolution of the GFX's XPan crop mode. It's very possible that a GFX body with a more pixel-dense sensor would likely trump this stitch's resolution.

While many may overlook the Micro Four-Thirds system for something more conventional, such as full-frame or APS-C cameras, creativity can take the systems to new heights and help cameras punch above their weight class.

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