WHEN AND WHY TO CONSIDER SHOOTING IN 4K

 


I’ve been shooting a lot in 4K over the past year.  I know there has been a lot of buzz about 4K, and I've been thinking a lot about which situations really could benefit from shooting in 4K and I wanted to share my thoughts. So here goes:

WHY DO I NEED 4K?:

1. VISUAL QUALITY.

Images rendered with a 4K sensor can capture an extraordinary amount of detail, subtlety of color tones, and in particular, skin tones look very realistic and complimentary.  Talent really looks great shooting with a 4K sensor, and you can see it, even when you scale down to HD resolution.

2. ABILITY TO RE-FRAME FOR HD OR 2K DELIVERY.
If you consider that 4K is four times 1920x1080 HD, then you can crop in 75% and still be in full HD resolution. This gives you tremendous control over your final image. I just filmed a complex dolly shot with many actors and rehearsed timings. Instead of shooting three sizes on it, we could shoot it once head to toe and in post can re-frame for an additional medium shot and a close-up take with no quality loss in HD.  With limited time with the actors, this helped us tremendously.

3. GREEN SCREEN WORK AND GRAPHICS APPLICATIONS
This is really the holy grail for this type of work. You are capturing so much detail in an uncompressed format that previous problems in keying - corkscrew hair, fly-aways, blond hair, thin objects- all key perfectly.   I’m also finding that graphics people love having the 4K resolution for any type of work they may be doing

4. MATERIAL DESTINED FOR THEATER SCREENS OR 4K PRESENTATIONS.
We shoot a lot of talent and directors for film markets where their intros will be cut in with clips from their films.  The motion picture content is often in 4K.   When you shoot talent in HD and blow it up to 4K, the quality can be jarring, particularly in contrast to the film elements.  By shooting in 4K, you can have the image quality of your talent on a par with the the film clips.  We are also using 4K for pieces that we know will be shown in theaters before the main feature.

5. FUTURE PROOFING.
4K seems like a bit of a buzz word right now, but eventually 4K will become the standard acquisition format, just like HD is now. You may remember when HD seemed like a buzz word and standard def seemed good enough.  I really have no prediction as to how long this transition will take, but I know the studios and networks are beginning to shoot their films and shows in 4K, even if they are delivering in HD.  Netflix and Amazon are also shooting their original content in 4K and working on compression technologies to stream 4K into the home.  Here’s a link to Amazon’s 4K Ultra HDTV Guide: http://www.amazon.com/gp/feature.html?docId=1000947061

Some workflow considerations:
The Sony F5 and F55 will record full proxy files internally while recording 4K RAW, so you can edit with these smaller files and then conform in 4K.  These HD files are full broadcast quality as well.

4K RAW (best for graphics and compositing) does use a lot of data space - an hour is about 500 GB, so this is something to think about. The 4K RAW is a raw file, so it must be color graded in finishing or treated with a LUT (Look Up Table that renders the proper gamma curve and color rendition for broadcast).

The F55 can record a compressed 4K format that is about 1/4 the size of 4K RAW at 128 GB/hour.  That is about the same size as an hour of ProRes HQ.  This is a very good format for archiving 4K for future-proofing and for non graphics or green screen applications.  The F55 can record HD proxy files simultaneously as well.

I don't believe that 4K is right for all projects, but for higher-end shoots, green screen and graphics work, and projects that may be shown in theaters, you may want to consider it.  Archiving in 4K for the future is another consideration.  Sorry for so much technical information in here, butI just wanted to share these thoughts with you and would be glad to discuss any particulars in depth if you would like.


Steven Wacks