Monday, April 21, 2014

Why the Sony FDR-AX100 tops out at 60Mbit/s and Other News

Andrew Reid of EOSHD takes a look at Sony's FDR-AX100 in this piece: A very brief look at the Sony AX100 4K Handycam and uncompressed 4K HDMI

In it he asks this question:
XAVC-S on the AX100 uses a bitrate of 60Mbit/s for 4K. It is a shame there’s no higher quality mode for those who don’t mind slightly larger file sizes. XAVC is an important new proprietary Sony standard. Why such a tepid implementation? 
And when I saw that I thought "oh! oh! I think I know why" - because I encountered this when I was buying a memory card for the FDR-AX100.

There's a couple of confusing things about buying memory cards for this camera; one is that the camera specs are given in Mbit/s (or Mbps) while the memory cards seem to all be spec'd in MB/s. Here's the manual:

So if you're buying the FDR-AX100 you see that it writes at 60 Mbps, but if you look at Sony's own card, they quote:

The 64GB SDXC Class 10 UHS-1 Memory Card from Sony features a maximum read speed of 94MB/s and a maximum write speed of 45MB/s with minimum transfer rates of 10MB/s. 
The other thing is that they like to put the biggest number for the card, on the card...and that's usually the read speed, not the right(write) speed. It's that last number you have to worry about; minimum transfer rates of 10MB/s

And Sony's own manual just specifies Class 10 cards, and Class 10 cards must, according to Wikipedia:
Class 10 asserts that the card supports 10 MB/s as a minimum 
Oh, and the important thing: if you put 60Mps through a converter you get:

So to sum up, the 60 Mbps speed is about 3/4 of the write speed of a Class 10 card, and it's probably a good bet that you don't want to get much closer than that to the limit of the card.

Anyway, that's what I assume is going on.

Other News

H. Paul Moon has put together a video on rigging the Blackmagic Pocket Cinema Camera. Paul wrote to us:
Blackmagic Pocket Cinema Camera isn't the newest kid on the block anymore, but in its niche, it hasn't been eclipsed yet, and after learning a few more things, I've made another rather extensive commentary. Although it's about building up a rig around the BMPC, it has lots of general advice that would be of interest to your overall community.

Rigging the Blackmagic Pocket Cinema Camera: HolyManta, Rapid ND, Contineo Cage, Zacuto Z-Finder, Tascam DR-60D & Rokinon Lenses from H. Paul Moon on Vimeo.

GoPro Hero 4 to be 4K in 2014?
This piece from DGISE suggests that the upcoming Hero 4 will support 4K at 30 fps. I'm not too sure if it's a guess or a fact (honestly, I think that if they don't release a 4K GoPro this year that does 30 fps people will be saying they aren't really trying.)
GoPro Hero 4 is really capable of recording video in 4K resolution at a speed of 30 frames per second, 1080p at 120fps and 720p at 240fps, which became possible with the advent of the new SoC Ambarella A9 chip (dual A9 ARM Core ® CortexTM-A9 processor 1 GHz and FPU acceleration ) for advanced applications, wireless connection, and streaming video in social media.

Video Planning Overview | DP Best Flow
This is actually a couple of years old, but I don't think I've linked to it before. Richard Harrington provides an overview of planning out a video project.
If you do not make informed decisions early on, this may result in an enormous amount of time spent “cleaning-up” or “fixing it in post.” This can compromise the quality and vision of the work or require a redo, often at your own expense. With the proper amount of planning and decision-making, many “could be issues” become non-issues. The goal of planning is to determine what questions to ask and how to proceed with the decision-making

1 of 3 posts dedicated to the art of aerial filming!! Part 1: Flying and shooting with the Phantom 2 and Vision 2+ | Philip Bloom
Many of you know, I have been messing with the Phantom Quadcopters for a couple of months. I haven’t posted any footage until now, as I have been practicing and practicing and practicing etc… It seems easy to start with, take off, move around, zip off here and there…but it’s really not. To get good stuff takes a lot of time, and of course there are many other factors to consider too. Basically the law and safety.

PVC at NAB 2014 - DaVinci Resolve Gets More Edit Friendly | ProVideoCoalition
Sure Blackmagic Design had important new camera surprises but it was the new features of DaVinci Resolve that most caught my eye. Why? Because they have added even more editorial tools to Resolve v11 and are building it into what looks to be a quite capable editor.

Camera Angles for the Crop | Cinearchive
North by Northwest is my favorite movie, so of course I like this; a breakdown of all the shots for the famous crop-dusting scene:
The crop dusting sequence from Hitchcock’s ‘North by Northwest’ is one of the most iconic in all of cinema and the real life location can be seen on Google Maps. The scene was meant to take place in northern Indiana, but was actually shot on Garces Highway (155) near the towns of Wasco and Delano, north of Bakersfield in Kern County, California. —FILMdetail

1 comment:

MoWoCo said...

This is simple. No matter the cost or resolution, it's still a consumer level handycam. Higher bitrates will be reserved for the XDCAM and proprietary media. Sometimes I wonder if EOSHD thinks through some of his reviews.