Diffusion For HD
Published : 14th October 2003
(Information Updated - 18th Sept.
2004 - Editorial)
Can anyone recommend a diffusion filter for 24p? I'm shooting for television, not film. I'm looking for a light touch, working with a male subject.
I've used Regular ProMists, Black ProMists, and Soft-FX in the past, all without problems, but then, I don't shoot stopped down when using diffusion anyway. I've heard that Classic Soft has too large a "lenslet" pattern which tends to be in-focus too often on wider shots. Other people like the Tiffen Diffusion-FX (Black or Gold) for HD.
There's no right or wrong answer. And it depends on the look you want - some diffusion filters produce a visible effect that creates a distinct look, while others are more invisible and meant really just for softening close-ups without creating any "diffusion filtered" look. The ProMists, Fogs, LowCons, which are all light-scattering designs, tend to create a slightly rougher, "noisier" texture that some people like (it makes the image feel more film-like to them because it is reminiscent of a grain structure) while others don't because it creates a noisier look.
Just make sure that if this for downconversion to standard def, there isn't too much edge enhancement being added in the downconversion process.
Cinematographer / L.A.
As I understand it, the technical definitions (and in Australia-legal requirements) refer only to digital sampling rates and structures. 16mm Negative is measured by Kodak at 5 line pairs per millimetre and therefore well above the horizontal and vertical sample structure required for 1080p HD.
None of the standards I have seen refer to anything which occurs in front of the image capture device (strangely this also includes lenses) or the sample cancelling effects of HD cross conversions (eg. 1080 24p to 480 60p)
I hope this helps.
Ben Allan ACS
Director of Photography
Editorial Addition :
The following information has been added to this page on the basis that it significantly relates to the thread of the topic...
Jim Iacona is a San Francisco based DP. He has developed the 'i Ring' which helps cinematographers attach nets to the rear element of lenses. The 'i Ring' product is compatible with HD cameras and lenses.
Please find listed a link to the 'i Ring'...
The standard 'i Ring' is compatible with most B4 mount, two-thirds inch chip HD (and SD)cameras & lenses. The Zeiss DigiPrime 'i Ring' is a variation on the standard 'i Ring' and is compatible with DigiPrimes. All 'i Rings' made for B4 mounts are compatible with Vipers, F900's, Varicams, etc. fitted with B4 mounts.