Gemini 4:4:4 RAW: Your 4K/2k/1080p Recording Solution
- March 13, 2013
- Shane Hurlbut, ASC
As all of you know, I have been doing an intense round of camera tests for Need for Speed. These tests involved nine cameras in total. Trying to leave no stone unturned was the agenda. This test did not stop at just cameras, exposures, filters, ISO, etc. We needed to test not only the sensor, but its capture medium. We selected three to test: the on-board SxS cards at 2k 4:4:4 ProRes out of the Alexa, the Alexa with a Codex S Recorder, and the Canon C500 with the new Gemini 4K RAW Recorder.
Protecting your negative is so important. Coming up with the right solution that works for your set etiquette, post workflow and individual budget is all part of the puzzle. The price differences between the three types of capture media were pretty extreme. Obviously, the SxS cards were the cheapest, but mainly because it was internal with the Alexa. The next was the Gemini. With its price point of around $5,000-$7,500, it was very inexpensive for a 4K RAW capture with a very unique way of pulling this off. I will get into more detail shortly. I have used Convergent Design recorders. They have made the Gemini for years and have a history of excellence with a very good price point. For all of the owner operators out there, if you are buying the new C500, this will keep your overhead down.
Now on to the finer details. I am all about keeping things compact and mobile, and the Gemini has this in spades. It is very small and has a very cool on-board monitor so that you can immediately check the digital gate. It also has very user-friendly commands to get you recording at specific frame rates. It is so small because it records to two separate SSD cards at the same time. I thought this was genius in terms of design. Frame one is on card one and frame two is on card two, frame three on card one and frame four on card two and so on. This keeps the footprint slim and mounts onto your camera like an on-board monitor.
The connections are very simple: one or two 3G SDI cables out of the C500, Alexa, C300, etc. to this recorder. Alexa Family: 16:9 (2880×1620) up to 60fps, (4:3 (2880×2160) up to 48fps, planned) Canon C500: 3840×2160/4096×2160 up to 30fps (60fps support in late 2013 with new SSDs).
One of the limitations of the Gemini is with frame rates, in that you can only shoot specific ones. You cannot roll out 22 fps or 48fps. It can record 23.98/24, 25, 29.97/30, 50, 59.94/60, 100, and 119.98/120 FPS. Now this is until the SSD cards catch up with Convergent Design’s mad scientists back at the lab. HA HA. They have been way out in front of this capture, but they are saying that they will be able to do 60fps by the end of the year on Canon 4K RAW. So with one recorder, you can only record 23.98/24, 29.97/30. If you want to go higher than 30fps, it requires a second Gemini at 4K RAW, or you can go up to 59.94 at Half Raw with one Gemini recorder.
We have one unknown tip that we discovered in our test. By shooting at 2K on the C500, we were able to gain almost another stop of latitude in the highlights. This was huge. It opens up a can of whoop ass for those of you who might not want to shoot 4K and deal with all of the huge media files in your post process, and with this, it also opens up more frame rates that one recorder can do. Very exciting times.
Why test a recorder? It’s all 0’s and 1’s, right? NOPE! It is not just for the quality of how it looks on the screen, but the workflow process and ease of file management. The Gemini quickly rose to the top. Its reader was cost effective, as well as speedy for ingestion into the Bertone Visuals Dardo DIT cart. You have to change your etiquette up a little bit, and this is a pearl of wisdom. Labeling these cards is so important because you now have two coming off, not just one, and sometimes you will have four coming off with high speed. We label them 1A, 1B, 1C, and 1D. We know that back at the DIT cart, all of these cards go together to create one media file.
The Gemini 4:4:4 recorder powers off of 6 to 19 volts via p-tap power, 4pin to Xlr, or can be powered off of an optional battery pack. The SSD drives are loaded into the top of the recorder, and there is a locking screw to prevent them from coming loose. The cool thing is if the recording process is interrupted (loose sdi cable, camera powering down etc.), the recorder will display an error message and reassemble the clip in the recorder to keep as much usable footage as possible.
Each roll or two, SSDs are unloaded and transferred to the DIT cart with a transfer station via thunderbolt, Esata, USB or firewire. The Gemini clip merger is then used to reassemble to frames from each SSD in order. When reassembled, the Canon raw .rmf files can then be converted to whatever flavor of files is needed for post, .Dpx, Pro Res or DNxHD, to then be sent to editorial. An additional .wav file for the audio is also transferred with the .rmf files. This works well with shooting to the CF cards on the C500 for a quicker offline edit to then be matched with the raw footage from the Gemini.
Small footprint, easy to use, priced right and just plain works well. We are slated to use six of them on Need for Speed. They will be with our C500 plate unit, which will be recording all of our high speed racing plates at 60fps. Geo Film Group has made four C500 crash cams so that we can put these cameras in harm’s way, and inside are two Gemini RAWs!