[opendtv] Re: Line Pairs/millimeter vs. Price vs. Image Format Area

In a 2/3-inch 1920x1080 video camera, you need to get 960 line pairs into 9.6 mm. That's 100 lp/mm.
In a 35-mm-movie-frame-format 1920x1080 video camera (such as the Vision Research Phantom HD), you need to get 960 line pairs into about 25.4 mm. That's 38 lp/mm.
Are you saying it's easier to make a lens that can provide 100 lp/mm lens than one that can provide 38 lp/mm? You'll have to do a lot of explaining to convince me of that. 

TTFN,
Mark



dan.grimes@xxxxxxxx wrote:
I may have miss understood, but what I heard from Bert was that considering two lenses with the same qualities but covering a different image area, a larger format lens is cheaper while Craig said the opposite is true. If that is what the argument was between, I must agree with Craig. In my years of buying and testing lenses for film cameras, a lens that must cover a larger image area and maintain the same overall qualities is much more expensive. While it is true that the MTF of the system needs to be considered for the overall performance, when considering the lens only, it is more difficult and expensive to make a lens to cover a larger image area and still maintain all the positive qualities (max. resolving power, light transmittance, colorimetry, MTF, etc.) Naturally, technology has helped increase the qualities, format area AND reduce the cost, but when comparing lenses of the same generation, I believe my statement holds true. If this is not the argument and I am lost, please feel free to ignore me! 

Dan Grimes




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