FS700 Slow Motion Function. Can Someone Explain This For Me?

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Sheldon Charron

Well-known member
I'm looking at the possibility of buying one of these and I'm not sure I understand correctly, but can someone confirm whether or not slow motion can be activated during recording at the touch of a button? If so, where is this button and how quickly can it be accessed and activated? I'm also guessing that if you can do that, you simply preset which FPS you want to assign that button ahead of time and it stays that way until you change it?
 
No, you select a frame rate before filming. It takes a second or two to to switch modes.

The videos you see where the speed changes dramatically -- those are filmed as high speed, then the speed is ramped up and down in post. It's way easier that way anyhow, as you can pick the exact point where it ramps, how much, etc.
 
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Oh sorry. I understand how you have to deal with it in post. What I want to know is if you can switch frame rates on the fly while shooting, or you have to stop filming, go into a menu, change frame rates and then start recording again. The way I've heard it described is that you can quickly hit a button and start recording at say 240 fps. Especially since you can only record for 9 seconds, I'd obviously want to save that for specific moments, but it would be nice to activate it on the fly. I'm guessing I misunderstood and you cannot.
 
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You don't have to go the menu. There is a button on the side s&q you just press that and you are in slow motion mode basically. The only thing you would have to do is change shutter speed if needed and choose frame rate. You are ready to roll.
 
Okay so let me see if understand correctly... Let's say I was shooting a fisherman who has a fish on, and I wanted to try to capture the moment when the fish jumps out the water. I would shot in say 240 FPS all the time, then just hit the button the moment I think the fish will exit the water, then conform the non-slow motion footage that is recorded at 240 fps back to 24fps in post? Or can I set the slow motion button to 240fps, then shoot at 24p until the moment I want to shoot slow motion, and when I hit the button it changes the frame rate for me and begins the slow motion sequence?
 
For the fish case use End Trigger mode. After entering super slow mode, the camera will start buffering to a queue, which constantly refreshes and tosses the oldest frames. You press record at the End of the event you want. Then you'll have N seconds pre-recorded video, where N is set by the frame rate chosen (higher frame rates have less recording time).
 
End Trigger mode is AMAZING. I had to film a guy trying to do a skateboard trick. It took him about 20 tries, but I had end trigger on and when he finally landed the trick, I just hit the record button (records the last 9 seconds) and saved tons of disk space and having to edit through lots of junk footage.
 
gene_can_sing said:
End Trigger mode is AMAZING. I had to film a guy trying to do a skateboard trick. It took him about 20 tries, but I had end trigger on and when he finally landed the trick, I just hit the record button (records the last 9 seconds) and saved tons of disk space and having to edit through lots of junk footage.
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That's fantastic. :) So you had to set your camera to 120 or 240fps, set your exposure (I realize now, and understandably so, that the exposure changes when you select slow mo), then wait...

Question: What if I wanted to film up to a moment, then select slow motion quickly? How much time would it take me to change settings and exposure to accomplish that?
 
You couldn't, realistically. But what you could maybe do is have a Ninja or Samurai external recorder attached for your live stuff, and then use the onboard camera recording for the slow-mo using the end-trigger function.
 
Barry_Green said:
You couldn't, realistically. But what you could maybe do is have a Ninja or Samurai external recorder attached for your live stuff, and then use the onboard camera recording for the slow-mo using the end-trigger function.
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Thats a good idea Barry, I hadn't thought of that.
Although I wouldn't shoot that normally, I could see it having it's place.
 
Some lag times worth noting....

If you are using "Start Trigger" mode - (ie, the beginning of the action is more important than the end, and the action time exceeds the buffer time of 8 or 16 seconds), then it is extremely important to note that there is a DELAY of approximately TWO SECONDS before slow-mo recording begins.

In other words, if you are controlling the start of the action, you need to press record, count (slowly) "one-one-thousand, two-one-thousand, GO" in order that you actually record the beginning of the action.

Sony's official response on this is that the FMU has a delay of 1 second, and that cheap SD cards have a delay of 2+ seconds, and it's just "the way it works". In my testing, this is incorrect, all recording media has a delay of 2(ish) seconds, even SanDisk Extreme Pro 95MB/s UHS1 SD cards. The FMU is neither faster nor slower to record than any decent UHS1 SD card capable of 25MB/s or more (but the FMU is MUCH slower to offload via it's USB2 port than a decent SD card in a USB3 reader).

After the slowmo recording buffer clears, there is at least 1 second of delay before a new "Start Trigger" recording can be made. In "End Trigger" mode, there is a significant delay (approximately the max slowmo record time) while the buffer is filled with the previous X seconds (X depends on the slowmo frame rate) before you can record a new slowmo segment.

Switching in and out of slowmo mode is not instantaneous... you hit the S&Q button, and there is at least 1 second before the REC button becomes active again. It sort of feels like Sony may not have used a sufficiently fast embedded processor in this camera.

Switching in and out of slowmo can be configured two ways. By default, when you press the S&Q button, you will first go to S&Q mode, where you can adjust frame rate within the realm of 1 to 60P FPS, resulting in continuous slow or quick motion. Hitting the S&Q button a second time takes you to Super Slow Motion (SSM), the 120FPS, 240FPS, 480FPS & 960FPS buffered "super" slow motion mode. This makes getting to SSM ever slower, so if SSM is what you (only) want, you can configure in the camera menus that the S&Q button only take you in and out of SSM mode.

While I love the full HD SSM this camera delivers, the sluggishness of the camera to respond can be very annoying. This is a camera that you really have to pay attention to the monitor to make sure it's ready and recording. And never forget your 2 second count in in "Start Trigger" mode... you will lose great footage if you do!
 
Barry_Green said:
You couldn't, realistically. But what you could maybe do is have a Ninja or Samurai external recorder attached for your live stuff, and then use the onboard camera recording for the slow-mo using the end-trigger function.
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that is a really great idea, I wonder if anyone here has tried it. I was trying to think of a solution where I could record normally but also use slo-mo at my disposal.
 
Barry_Green said:
You couldn't, realistically. But what you could maybe do is have a Ninja or Samurai external recorder attached for your live stuff, and then use the onboard camera recording for the slow-mo using the end-trigger function.
Click to expand...

When using slomo, once the camera is done recording with either trigger, the video is written to SD memory while playing to the output at 60p or 60i (can choose in settings). This will allow you to record slomo externally, but will prevent live capture while being written out. Strangely 24p isn't supported when writing out slomo via external, so in most cases 60i will need to be used (where 24fps is encoded with 3:2 pulldown). Couldn't get my Convergent Nano to remove pulldown- not sure if special settings are needed.
 
Alister Chapman has an interesting article on recording slowmo to external recorders, basically he indicates you need one that supports 50p/60p, which as far as I can see, none of the less expensive ones do:
http://www.xdcam-user.com/2012/06/uncompressed-slow-mo/

It seems there is just no way around the time that the camera spends writing out the slowmo buffer, unfortunately, since we already know the HDMI shows us the buffered slowmo being written (any attached monitor confirms this), and according to the article above, you can record the uncompressed, buffered slowmo over the SDI. The real-time from the sensor is simply not available while any aspect of writing slowmo is happening.

I work around this by using the excellent HDR-CX760V as a "B roll" when there is a lot of action I expect to want to use the FS700 slowmo on (sure, you can use any more expensive camera too). Depends what you are shooting, I guess. Mostly I shoot sports, extreme sports & interviews, so I do not use the FS700 like a "cinema camera", and shallow depth of field is not too important to me (while the HDR-CX760V matches the FS700 quite well in image quality for B roll, it has the limitless DOF that all small sensor cameras are prone to).

I also like to shoot the FS700 at 60p, then you can interpret the footage to 30p in post, speed it back up by 200%, and grab very good quality 50% slowmo sequences anywhere you want by reverting that sequence to 100%. In my case, I find that the likes of Twixor are not even required, so it's a very fast solution for me. Your mileage / kilometreage will vary!!!.
 
Old topic but i figured out yesterday that one could combine the FS700 with a Q7 recorder and skip the buffering and recording time as follows: camera on end trigger, SDI cable to the Q7 and set the Q7 to Record trigger. As soon as the Fs700 gets in slomotion mode you press the record button on the Q7 and its starts to record the FS700's buffer. technically speaking you'd be able to record slowmotion non-stop until the SSD's are full. its still 4K 100/120 fps only though but its a nifty lifehack kinda thing to skip the buffer turn-around time after record and you'd not miss the next cool thing after you pressed the FS700's record button.
 
It doesn't quite work that way with the FS700 and the Odyssey7Q+. In 2K the camera will output RAW up to 240p continuously, so the Odyssey7Q+ can in fact record this continuously in either RAW or Apple ProRes until the SSDs are full. In 4K 100p/120p, the camera fills up the buffer for about 4 seconds and then plays it out to the Odyssey in about 8-10 seconds, which is as fast as the data pipe can get it out over SDI. This is then recorded on the Odyssey7Q+ in either RAW or Apple ProRes. So it can only do a series of bursts rather than a continuous take.
 
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