On the Sigma Global Vision site, you may read and learn about every aspect of the evolution of Sigma. In this occasional blog series, we discuss aspects of the Global Vision in greater depth.
The Global Vision explains:
There are three requirements for outstanding lenses: fine design, precise manufacturing and inspection that ensures compliance with all specifications. Sigma lenses are born of well-thought-out design concepts and sophisticated, advanced Japanese manufacturing technology: the final clincher is our lens performance evaluation.
We used to measure lens performance using conventional sensors. However, we’ve now developed our own A1 proprietary MTF (modulation transfer function) measuring system using 46-megapixel Foveon direct image sensors. Even previously undetectable high-frequency details are now within the scope of our quality control inspections. The lenses in our new lines will all be checked using this new system before they are shipped.
Thanks to our new sensors, with their extremely high resolution, you can expect our high-performance lenses to be better than ever.
At the heart of the A1 measurement system is the same Merrill Generation 46 Megapixel Foveon sensor in the Sigma SD1 Merrill, and the Merrill Generation DP cameras. The incredible resolution of this sensor makes it perfectly suited to this advanced scientific purpose. The lenses to be measured are hooked up to the image capture device, and the special charts are captured and analyzed using new, proprietary algorithms designed to work in conjunction with the high-resolution sensor. This level of detail analysis is critical for creating lenses capable of meeting the demands of the most detailed image sensors in cameras such as the Sigma SD1 Merrill and the Nikon D800.
As you know, the 46-megapixel Merrill Generation Foveon sensor is APS-C format, capable of both super high resolution and super micro detail. So, in order to test the lenses edge to edge, and corner to corner, to cover the entire 35mm image circle, the first test image is made at the center of the frame, and then the sensor is moved to a corner of the image circle, and repeated for each remaining corner. The data is analyzed and the tester then determines if the lens has met the quality control standards.
And every new lens designed in the Contemporary, Art, and Sports lines will be tested with the A1 device–meaning 100% of the lenses built will be analyzed and approved before leaving the factory in Aizu.
Today’s best-resolving cameras demand lenses with the highest level of optical performance, and using A1 MTF testing on every lens produced ensures the each lens manufactured is up to both the high standards of Sigma and the demands of the most discerning photographers–and their cameras.
The first of the new lenses, the Sigma 35mm F1.4 DG HSM is available now.