Sunday, June 14, 2015

Creating large panoramas using multiple images from the Leica M 240

I have been experimenting lately with creating high res panoramas by stitching individual images together into one large photo. For those of you who have been following my blog, you may recall that I was testing the idea of combining a Sony A7R II with Leica lenses to use for this purpose. I am trying to find the best camera/lens/software combo to provide the highest resolution images to use for the final assemble panorama.  The A7R II would give me a 42.4mp image and the Leica lenses would provide the high quality optics, thus combining the best full-frame sensor available with what I consider the best full-frame optics.

The Sony A7R II isn't available yet so I decided to do some experimenting using just the Leica M 240 with its 24mp sensor. Below is an image I took last night of lower Manhattan at twilight. It is comprised of ten vertical photos, 2 rows of 5 photos each, and stitched together into one file using PTgui software. The lens was a 50mm Summilux with aperture set to the sweet-spot of f/5.6, ISO was at its its lowest, which on a Leica is 200, and shutter speed was 1/3second.

Ten images put together to form one giant panorama. The native size of the final photo is over 4' wide, but it could easily make a much larger print. 

Download the full res image (322mp) by clicking here.
Download a med res version of the image (100mb) by clicking here

The Leica was mounted in a vertical position on the tripod and centered for the nodal point of the lens. It was fairly easy to adjust the camera position for the nodal point by aligning a foreground object with a distant building and rotating the camera on the tripod to make sure that the two objects kept their alignment. It only took some minor adjusting by moving the camera back and forth to stabilize the alignment.

This is a typical rig I use to take the multiple images. The Leica M with Summilux 50mm lens, Really Right Stuff L-bracket, and a slider mounted on the tripod head.  The camera position was adjusted so the nodal point of the lens is centered over the tripod to give all ten images the same vantage point. When I need to do multiple passes that require the camera to also be tilted up or down, I also add a vertical slider. 

The rig I used is fairly simple, but then the Leica with 50mm lens is a very light camera so I didn't need anything more substantial. It consisted of a slider mounted on top of the tripod, plus a Really Right Stuff  L-bracket for the camera. I also have L-brackets for my Fuji X-T1 and Nikon D810 for doing similar work.

The ten images formed a grid of 5 across and two down. They were taken with the camera in a vertical position and allowance was made for approximately a 20% overlap of the images so the stitching software had similar reference points in neighboring images to make a smooth transition. 

The ten images need to be consistent so the camera is set to manual focus, and manual exposure. I shot the images in RAW and processed them as 16-bit tif files, which were then brought into PTgui for combining into one image. PTgui is very simple, drag-and-drop software that does a really quick and accurate alignment of the images but allows for later manual adjustments. I didn't need to adjust anything because the tripod was fully leveled beforehand.

I took this photo on a weekend evening, but it would be better to shoot during the week when more of the building windows are lit.

The sharpness of the Leica lenses and lack of anti-aliasing filter on the sensor often causes moiré patterns in buildings when shooting citiscapes using the Leica M. It is apparent here in the gold top of the building on the left -- something I'll have to deal with later in the final image.

The final image is 322mp in size, with a width of 51" (112.8cm). I have also tried some similar tests of combining ten images taken with the Fuji X-T1 and 35mm lens. Even though the X-T1 is a 16mp camera vs. 24 for the Leica, the final image was not much smaller (48" vs 51").

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