It Ain't All About Sharpness
 

I just finished reading this article on American Cinematographer about the making of the movie Dear Wendy:

http://www.theasc.com/magazine/oct05...ker/index.html

Here's an excerpt:

"Anthony had a very clear vision of what Wendy should look like, and he often showed me old black-and-white pictures of Indians taken by Edward S. Curtis (The North American Indian). They were beautifully soft, large-format compositions that had a painterly quality — very far removed from anything I imagined hi-def could look like.

We tested three different lens setups: the brilliant, ultra-sharp Zeiss DigiPrimes; a Pro35 adapter with a set of Zeiss Ultra Primes; and a Pro35 adapter with Zentropa’s good old Zeiss Standard Speed primes, which for quite a while were used mainly for student films. At first, I was a bit skeptical of the Standard Speeds. They weren’t perfectly sharp, and they also vignetted like hell because we had to shoot close to wide open — especially the 32mm! Anthony liked them because they were much smaller than the Ultra Primes.

When we watched the first test, I understood why Anthony wanted to go with the old lenses. Especially in combination with Tiffen Soft/FX1 and Soft/FX2 diffusion filters, the picture went quite far away from anything I’d ever seen on HD. The lenses’ natural vignetting gave the pictures a touch more depth that was quite different from what we could have accomplished through grading only."


Sometimes we go crazy looking at resolution charts or reflexively equate sharpness with good. Yet I hear in LA phrases like "HVX mojo"--not a particularly sharp camera, but somehow it looks right. I'm not saying sharpness is unimportant, I'm just saying a lot of times sharpness is actually equated with "the video look" that one might be trying to avoid.

I think it's extremely important to distinguish between "resolution" and "sharpness", which often get used interchangeably, but actually mean very different things.

"Resolution" can normally be taken to mean the smallest level of detail that can be discerned at all, "sharpness" is normally taken in a less exact way as an impression of how detailed something looks to the eye.

Which brings us to mtf graphs, which plot how well black/white transitions of differing resolutions are reproduced, whether they remain black/white, or become dark/light grey.

With film, the final resolution figure is often very high, but with the mtf rolling away from quite an early point. Video more typically doesn't have as high an absolute resolution, but keeps a high mtf for a higher percentage of that graph. It therefore gets perceived with a higher sharpness, whilst having a LOWER absolute resolution.

To get the effect that I think is referred to in that article, what's needed is for the mtf to roll away from quite an early stage, to give a "smoother" look. But this can mean that a higher absolute resolution (albeit at low mtf) can be even more important to make the image look "diffuse" rather than just plain soft.

It may seem perverse, but to avoid an all too sharp look, high resolution can be even more important. That's why detail enhancement can be far less on HD cameras than was necessary on SD cameras in the past. That's similar to the reference in the article to the old stills - "beautifully soft, large-format compositions" - I think they would be high resolution (large format negative) but the old lenses would have poor mtf.

That's why old Cooke S2/S3 lenses are still in demand for shooting 35mm and people spend thousands having them changed into PL mount lens.

There are periods when a softer look is in fashion, then that passes and a hard, sharp look is in demand. Also, different stories and actors have their own requirements.

One thing to do is test your lens/shooting format combination the way it's intended to be screened. What looks good on a monitor can be too soft when projected onto a 40ft wide screen.