Tuesday, 24 June 2014

My CineGear Presentation on the Sony F55: Part 2

My CineGear Presentation on a Sony F55: Part 2

Here’s partial dual of my CineGear presentation, in that we take an uncomfortably tighten demeanour during strength tinge and overexposure…

First, read Part One. Then, watch this video:

I’m preoccupied by over- and under-exposure. When we shot film we roughly never placed strength tones on a bearing that they were supposed to be.  I ran them a small prohibited or a small dim as a matter of habit. we can’t explain why; we theory we was usually ornery in my youth.

When we started sharpened video we consistently erred on a splendid side, and it took me utterly a prolonged time to comprehend why: video’s decreased fortitude done a design feel a bit murky to me, so we popped a critical things in a support with a bit some-more light to make them mount out some-more clearly. Whereas we grew out of regulating backlights and corner lights for subdivision in film, we grew behind into them in video.

Pushing strength tinge usually a small too distant resulted in unequivocally nasty shifts in tinge and chroma clipping, so we had to travel a excellent line.

Some cameras were some-more forgiving of splendid strength tones than others. we remember a Panasonic SDX 900 and early Varicams (some of we might need to mangle out your story books during this point) being many some-more forgiving than a array of Sony cameras, such as a strange F900 that seemed to have dual stops of overexposure latitude, tops! This softened with a F900/3 program refurbish (which, by a way, was a initial time we was wakeful that a camera could have a program update!), and a F900R serve softened both overexposure embodiment (and represented a sea change in how Sony cameras rendered color). Still, we always found myself exposing strength tinge a small on a high side, nonetheless reduction so in HD than in SD.

In SD I’d let strength tinge rise during 70%, though when we attempted that in HD we found that this was approach too hot. That confused me until we satisfied that SD video had “setup,” where a vigilance started during 7.5% on a waveform monitor, since HD did not—so a black fell during accurately 0% instead. What was before 70% in SD turn roughly 62% in HD, so exposing strength tinge during my former SD levels resulted in some bad-looking pictures. we fast practiced my technique.

As cameras softened they became many some-more forgiving of overexposed strength tone. Sony’s hypergammas gave us a initial outrageous jump in this direction, though it was Arri’s Alexa that unequivocally set a bar: scrupulously unprotected strength tones were beautiful, though overexposed strength tones were “filmic.” we set out to learn since and schooled utterly a lot on a way.

In partial one we discussed how film boundary tinge superfluity by dint of being a subtractive medium: a darkest colors are always a many saturated. Video camera manufacturers, not carrying any approach film experience, naturally worked to video’s strengths, where highlights are many saturated. They fast schooled that they had to hurl off superfluity in impassioned highlights or nasty things happened when a tinge channel clipped, though brief of that they were utterly calm to let tinge sate right adult to 70% on a waveform monitor. (Most of a luma information in a video signal—about 70% of it— is subsequent from a immature channel, so when luma hits 70% many cameras will start desaturating highlights before colors distort.)

Last year we achieved an examination comparing superfluity roll-off between a Sony F55 and an Arri Alexa, and we presented a formula to Sony during a new product concentration organisation we attended during NAB in 2013. They’d perceived a lot of requests to obey Alexa tinge superfluity roll-off, though this was a initial time someone had shown them what was unequivocally going on. Six months after they introduced a LC-709 Type A Look Profile, that attempts to replicate how Alexa and film hoop tinge superfluity in propinquity to exposure.

This story what we try to illustrate with a video above. we start out with normal Rec 709, a customary to that all HD apparatus is made, to denote how singular we are creatively when design constraint is firm to that spec. Rec 709 usually allows for about 6 scene-referred stops of energetic range, that is excellent in a studio with 0 contemplative surfaces and some critical makeup though not so good in a genuine universe of film-style video production. After that we uncover Hypergamma 7 which, during one time, was my go-to gamma bend when sharpened with Sony cameras. we suspicion it did a good pursuit of creation a video camera demeanour reduction “video-y” by rolling off a complicated camera’s extended prominence embodiment in an aesthetically appreciative conform though it still didn’t prove me. Highlights rolled off good though tinge superfluity in highlights was still an issue.

Sony, like many manufacturers, falls into a “if a camera can do it afterwards let’s use it” school: if a camera can make jam-packed colors afterwards it should. Asking them to lift behind a bit forced them to quarrel opposite their unequivocally inlet as camera manufacturers, but—to their credit—they listened to a marketplace and did it anyway.

The rest of a video shows comparisons between LC-709 Type A and Sony’s extended Rec 709 look, LC-709, that does not aggressively control superfluity in highlights; SGamut tinge facsimile vs. SGamut3.cine tinge reproduction; and SLog2 and SLog3. It also shows off their Cine + 709 look, that attempts to obey a tinge and contrariety of an tangible film print.

I don’t see a lot of unsentimental disproportion between SLog2 and SLog3.Some have pronounced that SLog3 is noisier, though of march it is if we demeanour during it directly: SLog2 puts center gray down during 32-33%, while SLog3 places it during a some-more Cineon-friendly 40% to open adult shadows a bit more, though grading will possibly lift SLog2?s center gray adult to 40% (where it falls in Rec 709) or pull a shadows down a bit in SLog3 so eventually it’s a wash. Looking during it directly doesn’t unequivocally tell we anything critical since record formats are meant for storage only: they reason information, they don’t arrangement it. You contingency class record footage in sequence to decider it.

The one large advantage of SLog3—which is something that Alistair Chapman told me immediately after my presentation—is that it pulls adult shade fact to a indicate where it is no longer heavily compressed. Video codecs have a lot of tricks adult their sleeves and a large one is that they chuck divided a lot of fact  in a darkest shadows. By boosting a shadows SLog3 indeed preserves fact by lifting it above a threshold during that XAVC and SStP aggressively chuck it away. SLog2 doesn’t do this, and in his experiments Alistair has seen some-more application artifacts in SLog2 shade fact than in SLog3. (This does not request to raw, that is uncompressed.)

I wish we found this interesting. I’ve got some-more entrance soon, including an essay we never approaching to write that came about as a outcome of comments that we perceived immediately after a presentation. Stay tuned!

About a Author

Director of photography Art Adams knew he wanted to demeanour by cameras for a vital during a age of 12. After 10 years in Hollywood operative on underline films, TV series, commercials, song videos, visible effects and docs he returned to his local San Francisco Bay Area, where he now shoots commercials and high-end corporate selling and branding projects.

When Art isn’t sharpened he consults on product pattern and selling for a array of suit design apparatus manufacturers. His clients have enclosed Sony, Arri, Canon, Tiffen, Schneider Optics, PRG, Cineo Lighting, Element Labs, Sound Devices and DSC Labs.

His essay has seemed in HD Video Pro, American Cinematographer, Australian Cinematographer, Camera Operator Magazine and ProVideo Coalition. He is a stream member of a International Cinematographers Guild, and a past active member of a SOC and SMPTE. His website is during www.fearlesslooks.com. Find him on Twitter: @artadams.

Article source: http://www.amateurphotographer.co.uk/news/Nikon_DSLR__image_scoops_railway_photography_prize_news_310985.html

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