Shooting Bruins Hockey with High Speed NAC Memrecam at 300 Frames Per Second

First of all, sorry for the quality of the blog pictures! I had to use my Blackberry. I was not ready to take photos for my website at the Bruins a few days ago. I was also not ready for the news that I would be experimenting with a $400,000.00 camera system!

I thought I was just covering a hockey game with a normal HDTV camera like I have hundreds of times. But this was not a normal day…

I have been shooting Bruins hockey for network television for over ten years. I am a hand held cameraman for hockey and I specialize following the puck with an ENG style camera on my right shoulder. I do not record to the camera, the camera is connected to a cable that runs down to a television truck. I am one of eight cameras inside the Boston Garden that bring the hockey game into your living room in high definition.

The last few seasons I have operated the only super motion camera in the building, the 90 frame per second Sony HDC-3300. I wrote a blog on this camera last year. Take a look at the video I shot talking about this high speed technology by clicking here. This year, the super motion camera was too expensive to rent, so I went back to the old Sony HDC-930 1080i 30 FPS camera. Nice camera, but not high speed!

But when I showed up for work a few days ago, I was asked if I would operate a “Hyper Motion” camera. Of course, I said yes!

The NAC Memrecam hi-motion camera technology is about four years old. The camera is made by a company called NAC, but it uses Panasonic technology to make it more “broadcast sports cameraman friendly”. In other words, the camera looks like a Panasonic VariCam on steroids. It uses the same CRT B/W viewfinder, the AG-HVF21G as found on the high end VariCams.

My biggest fear when asked to follow the puck and “shoot tighter than usual” was that the viewfinder would be muddy, delayed or blurry. I was pleasantly surprised to find out that the AG-HVF21G was sharp and clear. In fact, the shuttery look inside the high speed helps me to follow the action. I always ask for 1/120 shutter when working the game shooting with a normal camera.

Another worry for me was that the camera would be hard to operate, unbalanced and heavy. This was also not the case. The NAC Memrecam may have been slightly heavier than a normal HDC-930, but it was nicely balanced and the shoulder pad was very comfortable.

This camera used SMPTE fiber to send pictures back to the truck, or in this case data files. The high speed was recorded on solid state “cinemags” inside the camera body. The tape operator (down at the truck) controlling the replays from this camera had full control of the files (to be rendered) off the camera’s internal memory.

The files were rendered to a separate HD EVS tapeless replay server and the resulting 300 FPS footage was played back using this standard EVS. Bit complicated and that is why I’m not a tape guy, or is it a hard drive guy?

I had intercom communications with program sound back to me as well. Another bonus was the high definition return video (two feeds) back to me. I was able to see program in return one and watch my high speed footy get rendered to an EVS in return two. I should note that the camera only records for 22 seconds in an infinite loop until the tape guy back at the truck breaks the stream to render. When the stream is broken, I was still able to see pictures and returns in my viewfinder… but my camera images was not being recorded until the render was done!

I was told that the camera could record at 600 FPS and it was tested at that speed before I arrived, but the light inside the Boston Garden where not bright enough to expose a picture. The camera was set at 300 FPS and I had a heck of a time focusing the Canon HJ21×7.8 lens since it was wide open. I was asked not to shoot the crowd because there was not enough light.

The Canon 2/3 inch lens was mounted to the Memrecam using a special step ring. I found the crop factor to be about the same in the viewfinder as if this 21x lens was mounted to a 2/3 inch camera body. One thing I noticed was that the lens lost two stops of light sensitivity at the very end (telephoto) part of the zoom range. This is because the sensors are so very light hungry at the 300 FPS.

The Memrecam has three mono-chrome CMOS sensors. Each almost an inch in size. The sensors each pick up one color, red, blue and green. The larger sensor means shallower depth of field. Trust me, when covering a flying puck moving towards you at great speed, you want deep depth of field! I had to follow and pull focus as the puck got closer and closer! I would say fifty percent of my attention was on my focus using this system. I usually only apply twenty percent of my attention to focus on a normal tv camera! Focus for me “just happens”!

A prism sends light to each sensor and the camera has a fan inside to keep it cool running at the higher frame rates. I could hear the fan kick in occasionally, but it was not distracting.

When shooting action sports at high frame rates you start to see some really cool stuff. Take a look at the screen grab above. Look at the bend in the composite hockey stick as the player slaps the puck across the rink. Pretty cool eh?

The novelty of high speed digital capture in sports is gaining momentum. You see the technology at big events like the Masters, hockey and baseball Playoffs and at the Super Bowl. The buzz word has been “1000 FPS”. All the sports production people want 1000 frames per second. They change their tune when they see just how slow the action has become at the high frame rate. You simply cannot get a replay into the broadcast when shooting that speed. There is just not enough time.

So the key to high FPS use in sports is this: You need just one more frame past the point where you no longer have motion blur in the high speed action. So, in other words, hockey would be perfect at 400 FPS. At the rate I was shooting, 300 FPS, the blade and shaft of the stick was slightly blurred on a slap shot. 400 FPS would have been perfect, but then there is the light issue and the flicker!

I did see a problem with rolling flicker from the mercury vapor lights inside the Garden. It did not really show up when I watched highlights on ESPN SportsCenter, but you can defiantly see the flicker in the clips I posted here. This will all improve as these cameras evolve. In fact, the newest generation of Phantom cameras work great in low light, fight flicker and they shoot more frames in a second!

I loved running this camera. It was easy to follow the action and I hope to get to try it again in the future. Take a look at the video below to see some demo footage from the NAC Memrecam.

This video is not to be copied or displayed on another website.

Feel free to look for a de-flicker filter to remove the annoying rolling effect in the 1080p video file above. If you remove it, post the file and send me the link, I would love to see it.