This is a R&D request that I humbly bring up because I came over it in a real world situation
As Matt Uhry mentioned somewhere there is some serious need for 2K scaled. Yes there is and we badly need it.
2 days ago I shot a commercial on 35mm with 50fps all day. Delivery format will be Pal 576i. HD for broadcast is not there yet, an won't be in the next 5 or even 10 years at least here in Pal-World-Europe. Things are interlaced and sometimes need interlaced footage.
1. Often pans (range pack shots for instance) have to be smooth and for that reason they need in PAL world interlaced footage. 35mm is frames only and so is RED. If you want interlaced/fields you have to shoot 50 fps.
2. Some action has to be shot in 50 fps for slow-motion shots, you need that every day on a commercial shoot.
3. Depth of field of 35mm is compulsory.
Now, shooting 4k is great for quality and depth of field but cannot over-crank up to 50 fps. 2K windowed can do 50fps but does only use a portion of the sensor, hence the DOF of S16 which is not an option for serious commercial work.
As an extra benefit there will be more runtime and transcoding will be faster.
We need badly scaled 2K!
Please make this happen, for me personally much more important than on-board sound for instance... nothing against on-board sound though.