DA 55-300 vs DA* 300 f4

Started Sep 16, 2013 | Discussions thread
OP paulkienitz Veteran Member • Posts: 5,281
Re: DA 55-300 vs DA* 300 f4

jamesm007 wrote:

Photozones numbers! They come close in the middle; scaling from the K10D to K5 test cameras

"Scaling" between different sensors is not valid at all.  In the lower half of the photozone style graph, the readings are going to be the same across different sensor resolutions, and in the upper half, they'll separate, but it's impossible to estimate how much; the flattening at the top of the graph may represent a lack of ability to measure what the lens is really doing, as much as it represents a limit on the lens itself.  If one sensor shows 2400 lines and another shows 1900, the real lens performance could be anywhere in a broad range.

 paulkienitz's gear list:paulkienitz's gear list
Pentax Q Pentax K-3 Pentax smc DA 55-300mm F4.0-5.8 ED Pentax smc DA* 300mm F4.0 ED (IF) SDM Samyang 8mm F3.5 Aspherical IF MC Fisheye +4 more
Post (hide subjects) Posted by
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow