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I still miss my old Pentax screw drive lenses. They were high quality, robust and very light compared to today’s offerings. I think the new focus motors added a

I still miss my old Pentax screw drive lenses. They were high quality, robust and very light compared to today’s offerings. I think the new focus motors added a lot of weight but I am not sure.

jdietrich 8y ago
The focus motors in modern lenses are trivially lightweight, incredibly fast and largely silent. Modern lenses are heavy because they've got a whole bunch of big, heavy glass elements held in precise alignment by a big, heavy metal chassis. Modern sensors have an order of magnitude more effective resolution than moderately fast 35mm color film, which has made lenses the image quality bottleneck. Lenses that were good enough for film or 12MPix sensors are visibly soft on a modern full-frame camera.
- maxxxxx 8y ago
  Makes sense.
- pbhjpbhj 8y ago
  So are there innovations to address this? Maybe adaptive shaped sensors to accommodate lens aberrations?
- CydeWeys 8y ago
  What about the image stabilization sensors and motors, as those also trivially lightweight?
  - jdietrich 8y ago
    The sensors are a few SMD packages on a flat-flex and the motor is a voice coil with a few dozen winds of fine enamelled wire. The mounting system for the stabilized element is marginally more complex, but you're only moving one small element out of the dozen or so elements in a modern prime or the two dozen in a good modern zoom. It's pretty negligible, and it's becoming irrelevant as the industry moves to body-based stabilization. The Canon 50mm f/1.4 weighs 290g. It has seven elements and acceptable optical performance. The Sigma 50mm f/1.4 Art weighs 815g. Same focal length, same sensor coverage, same maximum aperture, same focus motor technology, but it has thirteen elements and vastly superior optical performance. More and bigger elements are necessary for a better lens, but big lumps of glass are heavy. There's no getting around that.

I still miss my old Pentax screw drive lenses. They were high quality, robust and very light compared to today’s offerings. I think the new focus motors added a lot of weight but I am not sure.

jdietrich 8y ago

The focus motors in modern lenses are trivially lightweight, incredibly fast and largely silent. Modern lenses are heavy because they've got a whole bunch of big, heavy glass elements held in precise alignment by a big, heavy metal chassis. Modern sensors have an order of magnitude more effective resolution than moderately fast 35mm color film, which has made lenses the image quality bottleneck. Lenses that were good enough for film or 12MPix sensors are visibly soft on a modern full-frame camera.

maxxxxx 8y ago
Makes sense.
pbhjpbhj 8y ago
So are there innovations to address this? Maybe adaptive shaped sensors to accommodate lens aberrations?
CydeWeys 8y ago
What about the image stabilization sensors and motors, as those also trivially lightweight?
- jdietrich 8y ago
  The sensors are a few SMD packages on a flat-flex and the motor is a voice coil with a few dozen winds of fine enamelled wire. The mounting system for the stabilized element is marginally more complex, but you're only moving one small element out of the dozen or so elements in a modern prime or the two dozen in a good modern zoom. It's pretty negligible, and it's becoming irrelevant as the industry moves to body-based stabilization. The Canon 50mm f/1.4 weighs 290g. It has seven elements and acceptable optical performance. The Sigma 50mm f/1.4 Art weighs 815g. Same focal length, same sensor coverage, same maximum aperture, same focus motor technology, but it has thirteen elements and vastly superior optical performance. More and bigger elements are necessary for a better lens, but big lumps of glass are heavy. There's no getting around that.