What is 4K HD?

[Jeff Barklage]

I notice a new 'format' in my Build 17 menu: 4K HD
What exactley is this? Is it a new aspect ratio?
Isn't 16x9 [1:1.78] "HD"?
Or is this something else?
And if it is something new, what is it and what does it do?

 

[David Mullen ASC]

I notice a new 'format' in my Build 17 menu: 4K HD
What exactley is this? Is it a new aspect ratio?
Isn't 16x9 [1:1.78] "HD"?
Or is this something else?
And if it is something new, what is it and what does it do?

Someone else who knows better will soon answer... but as far as I know, it means recording 3840 x 2160 (exactly 2X 1920 horizontally and 2X 1080 vertically) instead of 4096 x 2304. Apparently this makes a cleaner and perhaps quicker conversion from RAW to 1080P 4:4:4. I could be wrong though.

 

[Casey Green]

Someone else who knows better will soon answer... but as far as I know, it means recording 3840 x 2160 (exactly 2X 1920 horizontally and 2X 1080 vertically) instead of 4096 x 2304. Apparently this makes a cleaner and perhaps quicker conversion from RAW to 1080P 4:4:4. I could be wrong though.

I believe David has this one described accurately.

The only note I would add is that "4K HD" along with "4K 16:9" are not available when using an 8GB CF Card while also using REDCODE 36. They are, however, when using REDCODE 28.

All of the other media formats (16GB CF Card, REDDRIVE, REDRAM) do not have this limitation.

A chart of the available Media Formats, REDCODE options, and Frame Rates is available on pg. 28 of the RED Operations Guide (Build 18).

 

[J. Eric Camp]

Yes 4k HD is EXACTLY double 1920 x 1080.

So 3840 x 2160. It is slightly less rez than 4k 16 x 9 but the math for down rezing works out so much smoother that it makes for much faster renders. This will decrease your FOV a bit more but not drastically.

It's there because RED is thinking about their footage from many angles. Faster renders is just one.

 

[Jeff Barklage]

The quicker render times would be a true blessing.
Thanks so much for the information!!
I am constantly being told that the post houses are complaining about the render times...and this problem has become such a huge issue that the last 2 shoots I did [commericals] went from RED shoots to Vari-Cam shoots!
We were forced to use that crappy Pro-35 adapter with a zoom [a sweet fast Cooke 18-100 T3] and then place a telepromter on..this created a camera almost 5' in length! Crazy in practical environments, and all this crap we had to shoot through cut our light down to the point that my meter stated that we were at ASA 50!
As the actors squinted into the lens, I told the director "welcome to the 1950's!"
It too bad that post houses have the say over the director & DP now a'days...

 

[Ivan G]

So cleaner is one of the options for scaling down using 4K HD?

 

[M Most]

It too bad that post houses have the say over the director & DP now a'days...

That's not the issue. The issue is a matter of economics and turnaround time. The producer is the one who makes the calls, not a post house. Post houses need to be able to make money on what they do. If a producer is asking for everything that's shot on a Red shoot to be delivered quickly with the best quality, that's something that requires a lot of redundant hardware at the moment - something that the producers are usually not willing to pay for. So at least until there's another generation of hardware and/or software development for what Red is recording, the old adage of "fast, cheap, good - pick two" still applies.

Of course, there are always options (offline->online being one very simple one) should those involved be inclined to ask about such things.