keithcooper said:
The egami patent listings are alway hampered by my lack of understanding of Japanese...
However there is an interesting mention of control of distortion. Whether this refers to basic optical performance or 'perceived distortion' is not clear, since these are two very different things.
The Laowa looks to be an interesting lens ... I look forward to comparing it (on a 5Ds) with my 11-24
I just noticed that as well. I'm intrigued by what this would do.
[quote author=Patent Application JP,2016-081005,A]
[0077]
Next, with reference to Fig.12, it describes about the composition of the lens device 10 (optical instrument) in this embodiment. Fig.12 is an appearance perspective view of the lens device 10. The lens device 10 is provided with one imaging optical system 1 of the above-mentioned working examples 1-5, for example. The imaging optical system 1 is held by the body tube 2. The lens device 10 has the zoom operation means 31, the focal operation means 32, and the distortion operation means 33. When a user operates the zoom operation means 31, arrangement of the lens group of the imaging optical system 1 can change mechanically or electrically, and it can change a focal distance. A user can change the focal position (focus position) of the imaging optical system 1 by operating the focal operation means 32. Arrangement of the lens group of the imaging optical system 1 can change mechanically or electrically, and it can make it change from a normal state to a distortion changing condition, when a user operates the distortion operation means 33.
[0078]
As shown in Fig.12, the zoom operation means 31, the focal operation means 32, and the distortion operation means 33 are all ring shape, but the form of each operation means may not be limited to ring shape, and may be other form. Each operation means may be a button etc. to which each lens group is moved [ want / to make it ] electrically. The lens device 10 may not have either one or both of the zoom operation means 31 or the focal operation means 32. In addition to the zoom operation means 31, the focal operation means 32, and the distortion operation means 33, it may have the diaphragm operation means for changing the path of an aperture diaphragm.
[0079]
Thus, the optical instrument (lens device) of this embodiment has an optical system which has an aperture diaphragm, the Ath group that moves on the occasion of distortion adjustment, and the Bth group that moves by a locus which is arranged rather than the Ath group at the image side, and is different from the Ath group on the occasion of distortion adjustment, and a distortion adjustment device for performing distortion adjustment. The Ath group and the Bth group move to optical axis direction by a mutually different locus according to a distortion adjustment device being operated. An optical system changes from the first optical states (normal state) that have a first distortion aberration to the second optical states (distortion changing condition) which have a second larger distortion aberration than a first distortion aberration, when the Ath group and the Bth group move. Preferably an optical instrument further has a focal operation means for changing the zoom operation means for changing a focal distance, and a focal position.
[/quote]
As an enthusiast amateur I cannot justify an 11-24 Canon lens budgetwise. So an ultra wide third party MF lens would fully do.
