PBS Tonight:"400 Years of the Telescope" shot in 4k

According to today's NY Times preview, this documentary (10 pm ET) was shot at 4k, of course downconverted to 1080i, and theoretically capable of full 1080 resolution--although doubt the codec and PBS bit rates supports anything like that. Anyway, it covers developments from Galileo to today, with a special symphonic track developed for the show. (See 400 years.org .)-- John

^^^No idea. Doubt we'll pinpoint it--unless someone here has the inside scoop. -- John

Guess a question might be whether shooting with a ~4k camera but directly outputting only 2k or 1080i/p--a selected mode--provides the same benefit of recording a 4k data file, then downconverting to 1920X1080. AIUI, it's this downconversion/filtering that results in boosting the final effective resolution (potentially to full 1920X1080). Not sure if that's necessarily taking place shooting a reduced resolution (~2k) with a ~4k digital-cinema camera. Might depend on the camera. Got the impression from Arri's paper on 4k system theory , in Fig.15, page 15, that this microscan reduction (for film, or data scaling) was needed to fully benefit from such a downconversion.

Somewhat related is another Arri paper, "MScope: Anamorphic Capture with Dual CIF HD," in the April SMPTE Motion Imaging Journal; this might wind up on Arri's web site. The article outlines how a Arri digital-cinema camera, the Arriflex D-21, can shoot two odd-even-line 1920X1080 streams (720 active lines/stream) using a dual-stream recorder such as Sony's SW1, but with a camera anamorphic lens (optically compressing images horizontally). This provides a 1920X1440 recording that when optically re-stretched 2X results in 3840X1440 resolution for a 2.40:1 display ratio. By contrast, shooting 1920X1080 at 16X9, then cropping vertically for 2.40:1, results in only 1920X800 resolution because of the vertical blanking. Arri's Milan Krsljanin writes the short movie, Love Hate, was shot in London last summer using Mscope. -- John

Some awesome images. Too bad, for such a big topic, this wasn't a series. An intriguing mention was an upcoming mapping of the stars that will be online for anyone to analyze, just like NASA's rover images from Mars.

Can't say on-screen images here, despite 4k capture, were strikingly crisper than other 1080i. Despite viewing them on a Panasonic 65" 1080p TH-65VX100U plasma monitor installed just yesterday, it appears effective resolution is still limited to ~1290+ lines from Time Warner Cable and/or my SA8300HD cable box. [EDIT: Make that ~1335 lines, from a closer HDNet test pattern reading.] My former 9"-gun CRT RPTV delivered about the same restricted resolution. A pattern generator or other signal sources--perhaps a Blu-ray test disc--would display full 1920X1080 (from the plasma).

A large boulder next to an astronomer near the end of the documentary seemed more detailed than similar HD shots. But the vista of a distant observatory wasn't crisply focused. Believe there's a DVD available, like many PBS shows, but AFAIK no Blu-ray of '400 years'. -- John

^^^That D-21 camera mentioned in the Mscope outline above only uses a 1920X1080 section of the 35mm-size, higher-resolution sensor in its 1080p-mode setting. Believe the RED cameras do the same. So a 4k-sensor camera wouldn't benefit a 2k or less shot, it would seem. The first Arri paper linked does show 'sharper' images resulting from the oversampling/downconversion (plus graphs), which boosts the MTF, or contrast, at lower frequencies. Recall lots of AVSer owners of 480p plasmas touting how sharp downconverted HD images looked on their displays. For HD viewing with a HD display, it seems ideally, to capitalize on HD resolutions, you'd want both the sharpness at lower frequencies from oversampling/downconversion, plus greater maximum effective resolution--not so sharp a rolloff. -- John

Thanks for the details. Figured that crisp boulder and less-crisp background was planned. Only 4k shooting with a really crisp background vista I can recall, mentioned earlier here, was the updated Andromeda Strain--a shot in the desert with vegetation clearly defined way into the horizon.

Hope the 4k master/downrez makes it onto a Blu-ray. -- John

Reads like this would maximize any potential boost in effective resolution from 4k=>2k or 1080. Wonder if anyone has measured such potential gains in final effective resolution, say with spectrum analysis to show changes in MTF (like the Arri-paper graphs cited earlier above)?


Going from a 2k master to 1920X1080 for distribution, since these format resolutions are so similar, seems to waste the benefits of 4k capture for 1920X1080p distribution. Puzzling why they wouldn't make an exact digital copy of the original 4k to work with, although suspect computer costs and crunch time is a factor.


From your ~4k recording (RED One cameras?) and the best BR bit rate, seems this would maximize effective resolution, then. Although, if diffusion filters were used on the cameras, guess that could vary widely.

The many articles--and AVS posts--on HD images versus 4k (or 4k downconversions) imply most can't tell the difference, although comparison images often show less stair-stepping of thinner lines from 4k downconversion. -- John