35mm film vs 2.5K scan

[Joseph Podlesnik]

My personal aesthetic preference for cinema images would be something on a par with, say, what John Cassavetes used for his later films - Arri 35mm film. Do I really need 4K, 6K rez or 3D? My question is this: Is 2.5K rez comparable to that of 35mm film in resolution? I don't know any of the tech behind this. How would a 2.5K scan of 35mm film look? Would it look diminished? I ask because, again, for me a decent 'cinema measuring stick' would be the format in which John Cassavetes shot his later personal films. If my shooting tool (BMC, Scarlet, Ikonoskop, etc) is comparable to Arri 35mm film in resolution, I'm sure I would be satisfied. Of course there are questions of dynamic range, too. Thoughts?

 

[David Mullen ASC]

There's a difference between measurable resolution versus optimal scanning resolution. In theory, if your film image holds "x" amount of resolution, you should scan it at double that just to make sure you aren't adding any aliasing. In general, many people have discovered that 35mm film holds around 3.something K of measurable detail that needs to be scanned at 4K or 6K for archival reasons. But due to various factors, it is certainly possible for the film image to fall below 3K in terms of measurable resolution, especially if you are talking about a 1970's 35mm movie shot on zoom lenses, underexposed & push-processed, etc.

Here's an old article that shows that 35mm film should be scanned at 4K instead of 2K:
http://www.creativeplanetnetwork.com/node/44657

 

[Joseph Podlesnik]

Many thanks, David. I appreciate your expertise on this. Thanks for the link, too. Interesting to learn the visual and economic factors that come into play on this. Of course this makes me wonder: Was the DVD that I watch of Cassavetes' A Woman Under the Influence scanned at 2K or 4K? As discussed elsewhere by many, it may be that I use the 2.5K RAW BMC cam to generate the funds to eventually invest in a 4K RED Scarlet. Thanks again, David.

 

[David Mullen ASC]

Odds are high that a small movie like that was transferred from a film element (like an I.P.) directly to HD video (1920 x 1080) on a telecine. Second most likely is a 2K scan and then conversion to HD, and third most likely is a 4K scan. But I don't know. The Criterion DVD just says that it was a digital HD restoration, which could mean anything, but most likely either an HD video or 2K scan converted to HD video, after which clean-up tools were applied at HD resolution (but I don't know what film element they started with -- original negative or I.P.?). I don't think Cassavettes, if he were starting out today as a young man, would be nitpicking over pixel resolution, he'd be picking a camera that allowed his style of shooting (fast, handheld, available light, affordable, etc.) with reasonable image quality.

 

[Björn Benckert]

My guess is that it was a spirit scan straight HD 8bit or compressed 10bit HDCAMSR. going 2k and then downress to HD is not giving a better end result but the cost goes up as you then need to record to disk. Most restorations done during the "spirit years" went straight to HD for the tape convenience and the scanners has a lot of digital enhancement tools that can roll realtime in HD but not in 2K. Also it's quite difficult to see the difference of a well made HD DCP and a 2k DCP.

 

[Joseph Podlesnik]

... I don't think Cassavettes, if he were starting out today as a young man, would be nitpicking over pixel resolution, he'd be picking a camera that allowed his style of shooting (fast, handheld, available light, affordable, etc.) with reasonable image quality.

Brilliant, David. I agree - which leads me, of course, to wonder if the BMC camera, with these stylistic choices in mind, will do the job (the resolution is moderately high with decent dynamic range). Side note: did you know JC dismissed cinematographer Caleb Deschanel early in the shooting of Woman Under the Influence? The story I read is JC thought the photography was too self-consciously "pretty"? hmm... - http://johncassavetes.tumblr.com/post/20653638556/caleb-deschanel-and-cassavetes-cassavetes

 

[David Mullen ASC]

Sort of depends on if you can figure out how to rig the BMC for handheld... the footage I have seen from the BMC looks great (considering the low cost of the camera) and shows the power & advantage of RAW recording in terms of DR, except that the level of aliasing from the lack of an OLPF can be rather distracting on some shots, so be careful. I think the aliasing is harder to spot on the clips released on the internet due to the small image size but I wonder if on a big screen, some of it would be distracting. You may have to shoot with that in mind, avoid patterns that would easily create moire.

 

[Joseph Podlesnik]

Thanks again. I'm not planning to invest in BMC till Dec 2013; perhaps a v.2.0 with OLPF included will be in the works?

 

[Joseph Podlesnik]

David, I think I just found my solution -- New at NAB '13:

Blackmagic Production Camera 4K - $3,995
Super 35 Sensor
Global Shutter
Ultra HD and 4K
Built in SSD
Touch LCD
Metadata Entry
Compressed CinemaDNG RAW
ProRes
Thunderbolt
EF Mount
Free DaVinci Resolve & Ultra Scope

 

[dio Zafi]

for that Cassavetes look...handheld (pick up a 35mm camera for cheap) and 35mm short ends really cheap
the dcp coming from 35mm film is amazing