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Olympus Zuiko 24mm Shift
As many of you already know, I've been doing a series of tests on the very rare Olympus Zuiko 24mm Shift lens. I've been doing most of this testing with my good friend Jack Flesher, and now it's time to release some results.
Here's a photo of a sample lens:
http://www.thehatams.com/Images/Zuiko24Shift.jpg
A few things stand out about this lens:
The front element is made of a rare earth element, and the lenses are all hand-assembled. Very few were made, and this is a very rare lens.
The lens has a built-in set of color filters. There is a ring (near the built-in hood) that you turn to switch between "neutral", "Y48" (yellow), "O56" (orange), and "R60" (red).
The lens has a "FOV button", which toggles the apeture between wide open and stopped down to the apeture ring setting. This is a useful aid for manual focus. You set the apeture ring to f8, then when you need to focus, simply press the "FOV" button to "release" the apeture, and the lens opens up to f3.5. After you've focused, then press the button back in, and you're ready to shoot at f8.
The lens does not have a "tilt" capability, but it does have two separate "shift" axes. In the "landscape" orientation (horizontal), the lens will shift up to 8mm in either direction. In the "portrait" orientation (vertical), the lens will shift up to 10mm in either direction. For those of us who enjoy "stitched pano" shots, this is a tremendous advantage. We can now shoot two rows of images (by combining the two shift axes) without moving the tripod, and produce higher resolution images.
Pressure is used to shift the lens. This is fine (and very convenient) for lenses that are "tight". But some copies (mainly the well-worn copies) can get a little lose, and the weight of the lens can cause it to shift in the vertical position while mounted on the camera.
The lens requires an adapter to be used with EOS bodies. I used the cameraquest adapter for my testing. It's an exceptional adapter, and the lens easily slides in-and-out of the adapter, so you can use a single adapter for multiple lenses.
OK, enough about the lens, now let's talk about the testing...
Teseting Methodology
I worked extensively with Jack Flesher on this project. In order to accurately test these lenses, we spent three months acquiring as many copies as possible Overall, we ended up testing 8 copies of this lens, and I currently have 5 in my posession.
Next, we needed competition for this lens. The logical choice is the Canon 24-TSE. I tested four separate copies of the Canon 24-TSE, and used the sharpest copy for the comparison tests.
The two lenses have different shifting capabilities. The Zuiko shifts to 8mm horizontal and 10mm vertical. The Canon shifts 11mm in either direction, however Canon only recommends 7mm of shift in the horizontal direction (you'll notice that all the shift marks on the lens are colored red beyond 7mm).
Some of the tests compare the extreme edge of the full shift on both lenses. Some compare certain areas less-than-full shift. I've included a little of each below.
All shots were taken on my 1DsII at f8, tripod mounted, mirror lock-up, and timed release. All focusing was manually performed using an Angle-C finder. Multiple shots were taken of each image (re-focusing between each shot), and the best shot was used in the comparison. Basic processing was performed in RSE - white-balance and exposure were normalized, sharpening was set to 0, and "extract detail" was set to 20.
Notes about the test image:
The top image shows the whole scene. The 1st row of 100% crops (under the "whole scene") shows a comparison of "full shift". Next is a "partial shift" of the Canon which covers the same area on the image as teh Zuiko. Finally, a comparison of an interior area of the image at the 7mm shift point.
http://www.thehatams.com/Images/24Shift-Test1.jpg
Commentary:
The strength of the Zuiko over the Canon is most apparent at the full edges of the shift. The Canon has more CA, more light fall-off, and less sharpness. When you move in to the 7mm area, the difference in sharpness is less pronounced, but it's still there (look at teh detail in the wood post on the left).
This comparison was using my sharpest Zuiko and sharpest Canon. I've actually tested 8 different Zuiko's against 4 different Canons. On average, the Zuiko's are slightly sharper than the Canon's, have noticably less CA, and noticably less light fall-off.
The sharpest Canon (the one used in this test) is sharper than the "least-sharp" Zuiko, but just barely. Even then, I'd prefer the Zuiko for the advantages of CA and fall-off.
I was impressed with the overall handling and image quality from the Zuiko, and chose to keep the Zuiko over the Canon. I value the dual-axis shift more than I do the "tilt", so the Zuiko is a much better lens for me.
For anyone who does shift-pano-stitch type landscape work, this lens is a dream - it is simply the best wide-angle shift on the planet.
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