Smooth Slow Rec: The NX5′s slow-mo mode
I’ve occasionally used the HXR-NX5′s Smooth Slow Rec feature. It’s a lot of fun. The NX5′s manual, in typical Sony style, is a little unclear on exactly how to use it and what its limitations are; this blog post aims to get past that.
What is it?
Smooth Slow Rec (SSR) is a feature that allows the recording of 1080 High Definition or Standard Definition clips at four times the normal frame rate, which, when played back at normal speed, slow action down four times. What I mean by ‘normal’ frame rate is the default frame rate of the recording format your camera is using: In NTSC-land this is (almost exactly) 30 frames per second, in PAL-land this is 25 frames per second. Using SSR, you can shoot at 120 frames per second in NTSC-land mode, and 100 frames per second in PAL-land mode.
(The HXR-NX5U shoots what I call ‘NTSC-land’ frame rates, the HXR-NX5E shoots ‘PAL-land’ frame rates. You can get a WorldCam upgrade for either of these models which allows you to switch between PAL-land and NTSC-land modes. Ask your local Sony pro dealer or service center.)
1) You can’t shoot SSR footage at 720 lines’ resolution – only 1080 High Def and Standard Def.
2) You can’t shoot progressive-scan footage in SSR mode – it’s interlaced only, whether you’re shooting High Def or Standard Def.
3) No audio is recorded in SSR mode.
4) You can only use shutter speeds of 1/250th of a second and higher, up to 1/10 000th of a second.
5) You can only record clips of 3, 6 or 12 seconds’ duration in SSR mode.
6) 1080 HD SSR image quality is noticeably worse than normal frame rate 1080 HD. Furthermore, it gets progressively worse the longer the clip – 12 sec clips are worse than 3 sec clips. (Standard Def SSR clips are not significantly degraded relative to normal frame rate clips.)
6) SSR clips can’t be shot back-to-back because the camera needs about four times the clip length to record each clip to memory after it has been captured, during which time the camera is inactive. In other words, a 6-second SSR clip takes about 24 seconds to record to memory. This is true for both High Def and Standard Def clips.
7) You can’t record SSR clips to the onboard Secure Digital/Memory Stick memory and the FMU128 simultaneously, in other words you can’t do a realtime backup. You have to choose whether to shoot Standard Def or HD, and record this to one destination.
8 ) The camera cannot record an SSR clip across more than one memory card, in other words relay recording is deactivated. If there’s not enough space in the selected destination memory card for the whole clip, the camera will cut the clip short.
Smooth Slow Rec setup:
1) To put the camera into SSR mode, push either of the MODE buttons, select CAMERA via the touchscreen or navigation buttons, then select SMOOTH SLOW REC.
2) You’ll then get an option to choose whether to shoot Standard Def or 1080 HD footage, and whether to record this to memory in the Secure Digital / Memory Stick slots or to the FMU128 unit (if you have one). Make your choice.
3) You’ll then have to select the length of SSR clips you’re going to record. Choose either 3, 6 or 12 seconds.
4) You’re now set to go. Push a Rec button (don’t hold it down) to start recording a clip.
5) But wait, there’s more! Once you’re in Smooth Slow rec mode, you can hit either of the MENU buttons for more options. Do this.
6) At the top of the column of icons in the overlay that now appears on your screen, you’ll see a little film frame with SLOW on it. This is the SMOOTH SLOW REC SET menu. Here you can select the image quality of High-Def SSR footage under HD REC MODE. I always use the 1080/60i FX option for best quality, but this takes up more memory space than lower quality options.
7) The second item in the SMOOTH SLOW REC SET menu is REC TIMING, where you get to choose between START TRIGGER or END TRIGGER. This choice determines whether the camera records the footage stored in a buffer before the Rec button is hit, or the footage stored in the buffer after the Rec button is hit. When set to START TRIGGER mode, the camera will start acquiring a high-framerate clip in a buffer as soon as the Rec button is hit. Once the clip of either 3, 6 or 12 seconds is in the buffer, it then gets recorded to the selected memory. Buffering takes length of the clip in time, recording four times as long. In END TRIGGER mode, the camera is continuously recording a clip of the earlier-designated length to the buffer. When you push the Rec button, it will record the preceding 3, 6 or 12 seconds to memory. The Rec button is inactive during the buffering & recording process in both START TRIGGER and END TRIGGER modes, so once you’ve hit it you’re committed to the whole process of recording the clip. (I find END TRIGGER to be best for most occasions unless you can predict your subject’s movement.)
8 ) When in SSR mode, hitting either one of the MODE buttons will send you instantly back into regular MOVIE mode. You’ll have to go through the setup again to get back to SSR mode. Clip length, Standard Def vs. High Def and clip destination settings will have to be re-chosen, but HD clip quality and trigger settings will by default be the same as the previous time you used SSR mode.
You can change most of the camera settings in SMOOTH SLOW REC mode just as you do in regular MOVIE mode. SSR clips played back in the VISUAL INDEX appear slowed down, in other words they’re played back at normal frame rate.
What are your experiences with Smooth Slow Rec? Have I left anything out? Tell me by leaving a comment.