How Big of a Hurdle is 120FPS? at DVinfo.net

Tim Polster · November 1st, 2014, 05:05 PM

As many do, I watch the specs of new cameras and it seems like adding resolution is easier then adding FPS. I have hoped to own a camera that can record 720p120 (with audio) for quite some time now. With 1080p60 becoming a standard acquisition format, I thought 720p120 would show up as well since they share the same bandwidth.

Is the heat generated from reading the sensor too much or do the companies view this as an extraneous feature?

Thanks for your thoughts.

Mark Watson · November 1st, 2014, 08:40 PM

Tim,

I don't know of another camera out there that beats the FDR-AX100 at 720p, 120fps, for $2,000. I like the way it saves the files, in true 120fps format, as opposed to rolling it all into some 29.975 file format. The saved file is compressed of course, but with 120 progressive frames to work with, I can drop it on the Vegas timeline and it will play back in real time, or I can stretch it to be double-time, and up to 4x slow-mo playback. Sound is recorded! You can zoom while recording! Exposure controls work to maintain proper exposure while recording! Auto focus or manual focus are both available, while recording! And it's at a bit rate of 50Mbps. Not too bad for a consumer camera. Current is what causes heat. I don't know anything about sensor design but I think reading out the sensor is not a high-current operation, so maybe that's a non-issue. Granted, if you're writing more data to the recording media, say 200Mbps, that might involve some generation of heat, don't know.

For some stuff, 1920x1280 60p is the right speed. For vehicles like trains, cars, aircraft, I like 120fps, for natural stuff like pounding surf, 60p is enough, in which case the XF305 gets the nod, mainly due to better ergonomics IMHO.

HTH
Mark

P.S. Not sure where the line is drawn, but I've just promoted myself from "hobbyist" to "enthusiast".

Tim Polster · November 2nd, 2014, 08:38 AM

Thanks for your reply Mark. I just purchased a Panasonic PX270 which creates a very nice image. I was expecting to see a 720p120 mode when the camera was first announced since 1080p60 was included on the previous models a few years ago. But it is not there. Then I see more "consumer" type cameras with higher framerates like the Sony you mentioned and now I am at the stage of just asking why?

Maybe single sensor vs three sensor designs?

Mark Watson · November 2nd, 2014, 09:09 AM

Congrats on the new purchase. You might be on to something with the high speed not seen on the 3-chippers. I had never made that association. As for pro, pro-sumer and consumer... I thought I had an idea of what to expect in each category, but the latest round of cameras has blown all those theories out of the water. Canon seems to have a real aversion to high frame rate. C500 the notable exception. It must be much more costly to implement in a 3-chip camera and not seen as adding enough value to be worth it. I like the Panasonic P2 line but when I saw the cost of the media (2008 time frame) it was just a bit much for me. Are there really no 3-CMOS with 120fps? Can't think of a single one.

Mark

November 1st, 2014, 05:05 PM	#1
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	How Big of a Hurdle is 120FPS? As many do, I watch the specs of new cameras and it seems like adding resolution is easier then adding FPS. I have hoped to own a camera that can record 720p120 (with audio) for quite some time now. With 1080p60 becoming a standard acquisition format, I thought 720p120 would show up as well since they share the same bandwidth. Is the heat generated from reading the sensor too much or do the companies view this as an extraneous feature? Thanks for your thoughts.

November 1st, 2014, 08:40 PM	#2
Mark Watson Major Player Join Date: Oct 2008 Location: Whidbey Island Posts: 873	Re: How Big of a Hurdle is 120FPS? Tim, I don't know of another camera out there that beats the FDR-AX100 at 720p, 120fps, for $2,000. I like the way it saves the files, in true 120fps format, as opposed to rolling it all into some 29.975 file format. The saved file is compressed of course, but with 120 progressive frames to work with, I can drop it on the Vegas timeline and it will play back in real time, or I can stretch it to be double-time, and up to 4x slow-mo playback. Sound is recorded! You can zoom while recording! Exposure controls work to maintain proper exposure while recording! Auto focus or manual focus are both available, while recording! And it's at a bit rate of 50Mbps. Not too bad for a consumer camera. Current is what causes heat. I don't know anything about sensor design but I think reading out the sensor is not a high-current operation, so maybe that's a non-issue. Granted, if you're writing more data to the recording media, say 200Mbps, that might involve some generation of heat, don't know. For some stuff, 1920x1280 60p is the right speed. For vehicles like trains, cars, aircraft, I like 120fps, for natural stuff like pounding surf, 60p is enough, in which case the XF305 gets the nod, mainly due to better ergonomics IMHO. HTH Mark P.S. Not sure where the line is drawn, but I've just promoted myself from "hobbyist" to "enthusiast". Last edited by Mark Watson; November 1st, 2014 at 08:47 PM. Reason: sp.

November 2nd, 2014, 08:38 AM	#3
Tim Polster Inner Circle Join Date: Dec 2004 Location: Arlington, TX Posts: 2,231	Re: How Big of a Hurdle is 120FPS? Thanks for your reply Mark. I just purchased a Panasonic PX270 which creates a very nice image. I was expecting to see a 720p120 mode when the camera was first announced since 1080p60 was included on the previous models a few years ago. But it is not there. Then I see more "consumer" type cameras with higher framerates like the Sony you mentioned and now I am at the stage of just asking why? Maybe single sensor vs three sensor designs?

November 2nd, 2014, 09:09 AM	#4
Mark Watson Major Player Join Date: Oct 2008 Location: Whidbey Island Posts: 873	Re: How Big of a Hurdle is 120FPS? Congrats on the new purchase. You might be on to something with the high speed not seen on the 3-chippers. I had never made that association. As for pro, pro-sumer and consumer... I thought I had an idea of what to expect in each category, but the latest round of cameras has blown all those theories out of the water. Canon seems to have a real aversion to high frame rate. C500 the notable exception. It must be much more costly to implement in a 3-chip camera and not seen as adding enough value to be worth it. I like the Panasonic P2 line but when I saw the cost of the media (2008 time frame) it was just a bit much for me. Are there really no 3-CMOS with 120fps? Can't think of a single one. Mark