Shooting in 48fps

Most all things, like 24fps film, were an economic choice. Simplest sync for video was the electricity supply frequency. 60 in North America and 50 in most of Europe. It would have been nice to shoot video at this rate but there wasn't the available wireless bandwide for that to be economically used in broadcast systems of the time. Interlace transmitting solved this problem requiring only half the bandwidth and with CRT playback allowed the viewer to experience the temporal motion of 60 fps for NTSC. With LCD or plasma which are progressive displays that refresh at 60hz or more in NTSC, they need to deinterlace and create a progressive signal for the display to work. The quality of this deinterlacing is the key to how good the picture looks. Cheap TV's don't look so good. 60i fields are not combined to make 30p and then double as the fields are 1/60 apart so will not just add. The deinterlacing must create the missing information, the missing odd or even lines. The higher refresh rate sets delay the video and use more fields from which to create an interpolated progressive stream for the display at the refresh rate. This processing time tends to delay the video from the audio ( which is why most of these sets also have an audio shift control to re-sync the audio for each input). The 60i exposure rate is always 60fps for NTSC and by default gets displayed at 60fps or more on NTSC sets. Current NTSC consumer TV's are 60hz or more so that someone shooting at 30P will get the frames repeated to be a multiple of 60, much like 24fps film projector with a 2 blade shutter. ie film refresh rate with 2 blade shutter is 48, with a 3 blade shutter is 72 and a 5 blade shutter is 120. The temporal rate doesn't change its still 24fps. My film projectors are a 3 blade and a 5 blade models for Super8 film. For film projectors the shutter blades only effect the flicker rate as the film is still moved at its frame rate. For the high refresh rate TV's this is not true. For 60i input they can recreate the 60fps that the camera shot from the 60i input and increase the flicker rate or they can interpolate even more frames than the original . It is this feature that lots either like or dislike. However the higher refresh does give them the opportunity to do a better deinterlace.

Ron Evans
 
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MaxiVision 24-48 fps and Showscan 30-60 fps are 35mm and 70mm projection film formats. Because they were projection film formats there was little chance of success because these formats would increase distribution costs. However with digital 2K projection there really is no additional cost in supporting the projection of higher frame rates so it all boils down to the artistic choice of the movie Director. 4K digital projection is more technically difficult with higher frame rates.

The Blu-Ray format also supports higher frame rates in 720p resolution but not in 1080p.
 
androbot2084 said:
MaxiVision 24-48 fps and Showscan 30-60 fps are 35mm and 70mm projection film formats. Because they were projection film formats there was little chance of success because these formats would increase distribution costs. However with digital 2K projection there really is no additional cost in supporting the projection of higher frame rates so it all boils down to the artistic choice of the movie Director. 4K digital projection is more technically difficult with higher frame rates.

The Blu-Ray format also supports higher frame rates in 720p resolution but not in 1080p.
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there will be lots of added costs during the entire production. from storage while shooting, to added post costs (especially for vfx, cg, compositing, etc.) to twice as much space needed for delivery. double the framerate means double the data means double the storage which in some ways will double the cost. of course, the increased costs of an all digital production won't be nearly that of a project originated on film, but you can't just write it off as a simple creative choice with no financial impact.
 
Again if you want to shoot 48 fps and cut costs shoot and edit using the 2K format rather than 4K. Indies can even shoot the production in 720p with acceptable results. Of course lighting costs will increase when using higher frame rates. Peter Jackson may settle for nothing less than dual 5K at 48 fps but smaller formats can also look just fine. Even diehard film shooters can figure out ways to save costs using higher frame rates by using 16mm film instead of 35mm film.
 
snowleopard said:
Does anyone here remember the talk of Maxivision?

Roger Ebert has written about it a few times. Here's a good article.
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I remember that. It looks good, and has the motion/temporal feel like 50P/PAL HD. It will be very interesting how the Hobbit will come across at this rate. Showscan at 60fps was amazing to experience, just narrative material suffered
from that live feel that also 60i and 60P have.


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