Luminous Landscape Forum
Equipment & Techniques => Mirrorless Cameras => Topic started by: Guillermo Luijk on August 19, 2022, 05:44:34 am
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The Leica Q2 (FF compact camera with EVF and single lens 28mm Summilux f/1.7):
(https://i.blogs.es/58e8d0/leicaq2-0421/840_560.jpg)
has been designed with distortion corrections in mind which cannot be disabled by the user. I have no problem with this approach but wanted to do a RAW exercise to find out the distortion correction applied by Adobe Camera RAW. I introduced a regular grid (100px spacing) in the RAW data, reduced exposure by 2EV in the overall image and compared a neutral RAW development (DCRAW) with a corrected one (ACR):
http://guillermoluijk.com/misc/correctionleicaq2.gif
Taking one grid element in the far upper right corner we have the worst case correction scenario:
(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEifN7FCWzb6ZgFDjxGJRoXXKri7rv3F1UGXBfzxPFKdj3cO3jqMl8fbmzSagm-5ojscqi8kVgSqvusG9zZEwCa7EyZyZvnWFoF3S1z61mLD6GyXmdq6gr8SUXLvkOnC-ljDCpt3raY4DEUyOtkTbCHJxfQbhrRJDQzv-OauLjTzKl3yH42gicbEqNq4Ew/s16000/correcttion.jpg)
Just by counting pixels this means a 44% interpolation rate, equivalent to a 120% upscaling in pixelcount:
(https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhQB-RVmCSiFFFa6dwY7u36096dhBcWJYCQgmm3i19SApqCE7FW4PNf1YnFXQuz7PFDQIz26QTergzhveualYQ4sLijwZbYPdglUf9rHwbfu_xv6NTeX-eBtyiyYQ40PsnkYPchk6NV07o_Pv4gjUW5PUPutW9Wp9eZJUTWu21C8VWO4lcxHxfQYiAqYQ/s16000/interpolacion.png)
Regards
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... has been designed with distortion corrections in mind which cannot be disabled by the user.
This is true if you use ACR/LR. Capture One allows you to disable the correction. (Also opening the image in RawDigger will show you the uncorrected image).
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This is true if you use ACR/LR. Capture One allows you to disable the correction. (Also opening the image in RawDigger will show you the uncorrected image).
I was talking about the maker (Leica), not about the RAW developers. The lens was designed that way, like some others (e.g. Zuiko 12mm f/2),...
Regards
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I would say that they chose not to correct the distortions optically (expensive) because it is good enough to do them by software. That applies to a long list of lenses today, especially wide angles and zooms.
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I would say that they chose not to correct the distortions optically (expensive) because it is good enough to do them by software. That applies to a long list of lenses today, especially wide angles and zooms.
But not only expensive in price, also expensive in other regards such as size, CA, volume,... i.e. if you make a perfectly corrected lens you'll loose in other areas. Distortion correction is probably the most sucessful correction performed by software, so this approach of lens design with a fairly high amount of distortion makes a lot of sense in the digital era. This camera costs nearly $6000; I don't think Leica wanted just to save money.
The article: https://www.overfitting.net/2022/08/correccion-de-distorsion-geometrica-en.html
Regards