Add blowup sharpness section

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Matt McWilliams 2022-07-26 14:32:49 -04:00
parent a10aa7f7d1
commit b35824e35d
1 changed files with 18 additions and 1 deletions

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@ -107,3 +107,20 @@ The printer gate may hold 8mm film and the printer camera 16mm, or vice versa.
With a `M = 2` setup an 8mm original frame is photographed onto a whole 16mm frame.
With an `M = 1/2` setup a whole 16mm original frame is photographed onto an 8mm frame.
Conversion between any two film gauges is possible this way, provided the frames have the sane proportions, as 8mm, super 8mm, 16mm, and some 35mm do.
## BLOWUP SHARPNESS
A 16mm picture of a flea can be just as sharp as a 16mm picture of an elephant.
But a 16mm picture of an 8mm picture cannot be expected to be as sharp
as a 16mm picture of a 16mm picture.
Pictures differ from things in having very limited detail.
The 16mm blowup, even if it preserves all the pictorial detail of the 8mm original, spreads it out, so the blowup is less sharp absolutely than the original.
Under extreme magnification--a microscope objective could be the printer lens--pictorial detail is diffuse and the underlying natural thing, the emulsion, is all that could be photographed sharply.
But the grains are too small to be sharply imaged with light.
Here even the natural thing has been photographically exhausted.
An 8mm original blown up to 16mm and projected will appear sharper than the same 8mm original optically printed onto 8mm and projected.
If the blowup optics are good this is even true when the 1:1 printing is by contact.
Likewise for 16mm to 35mm.
(This is all due to the print film being in effect twice as sharp and half as grainy in a bigger frame.)