David C. Williams |
March 19th, 2009 03:55 PM |
Quote:
Originally Posted by Andy Nickless
(Post 1024684)
OK - I'm going to cheat (and rant) a little.
Here's another thing I dislike most about the EX1 - in fact, about every video camera I've owned to date (I can't afford those interchangeable lenses and for my work I need a small camera anyway).
Sony along with all the other manufacturers fit lenses that have f-stop (iris) settings from about f1.9 to f16.
But these lenses are UNUSABLE from f8 to f16.
If you inadvertently set your iris to anything over f6.7, the image is soft to say the least.
So WHY do they all do this?
(What's the point - apart from conning the poor buyer / operator)?
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They don't intentionally make it soft :) There is no lens on the planet that would help you, unless they somehow disobeyed the laws of physics.
It has to do with the optical low pass filter, the size of the sensor, and the iris. Once you stop down past around 5.6 your getting to the point where green light, the major sharpness component of vision, starts to become partially blocked. So your resolution drops.
The smaller the sensor, the tighter the optical low pass filter size, the earlier the f-stop begins to affect the resolution. It begins roughly at F4 on 1/3, F5.6 on 1/2 and F8 on 2/3.
You haven't been conned, you just weren't paying attention during high school physics :) Look up Airy Disc.
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