- Created on Sunday, 30 November 2008 20:00
- Last Updated on Friday, 14 December 2012 20:15
- Written by HW Stone
- Hits: 7044
On Wednesday, November 12th 2008 at 07:07PM EST, H.W. Stone wrote the following:
25mm of focal length is the same angle of view, no matter if the lens was "made" for 16mm film or 35mm-- and if it produces 100 lpmm [lines per millimeter], it doesn't care how big the image is, either, which means a really, really good "35mm format" lens that produces 125 lpmm is just as sharp as that super perfomer "16mm format" lens that produces 125 lpmm.
That's the big point you need to consider when you compare 35mm still camera lenses versus 35mm cine lenses-- the cine lenses are generally much higher in numbers of line pairs per millimeter, but not as "contrasty" as still lenses. Why? A still lens needs to take a 24x36mm negative and make a snappy, "pops in your face" 16x20 inch print, maybe-- the the cine lens only has to make smooth, flows one into the other images, just more like 30x20 FEET in size.
Because the 16mm frame is smaller the negative has to be enlarged more, but in real life "top quality" cine lenses for either 16mm or 35mm film exceed the resolution of the film, so use of a 35mm lens on a 16mm camera is no problem.
Until you try to put a Nikkor up there and wonder what went wrong.
Think of it this way-- as resolution (lpmm) goes up, contrast goes down, as contrast goes up, resolution goes down, and each is set up for the intended use.
He expanded further on Sunday, November 30th, 2008 08:27PM EST:
First, the size being much smaller, the 16mm lenses cost less to make, less to ship, and sell for much, much less.
Second, cine lenses are high resolution, low contrast, still lenses are higher contrast, trading off much lower resolution for more "pop" in the print. You need a still print to "pop" when you see it, but you don't enlarge a still anywhere nearly as much as you do a mopic frame, and high contrast looks cruddy when it is larger.
Third, still camera lenses have very quick focusing ratios, which get in the way of follow focus, tracking, and generally screw up a long shot.
HD resolution is so much LOWER than even 16mm film that a 35mm still camera lens looks good, and the chip lowers the contrast. Film has more latitude, can accept more contrast, and has much more resolution, so the problems show up-- but like the difference between hamburger and steak, grind up the image and you can mix in lesser size and mixed quality.