Procedure For Off-Speed (Slow Motion) Shooting with F950

Changing the frame rate of a Sony HDC-F950 camera in a typical system configuration, is a somewhat complicated procedure. The typical configuration I refer to is when the F950 camera is connected to a Sony HDCU-F950 CCU/Fiber base station. The reason is the CCU (sometimes together with the MSU) overrides everything in terms of setting and adjusting shooting formats.

There are 5 removable cards (circuit boards) inside the Sony HDCU-F950 CCU. The one marked "AT" (on the end) has a number of dip switches that control format parameters and frame rate. Normally the frame rate of the system is set and locked in using these dip switches (see below). So the frame rate is unchangeable, unless you change the dip switches. However, you can also assign external control of frame rate to the MSU (e.g. MSU-750) with a specific dip switch setting, as described below.

Locate the dip-switch on the AT card labeled MULTI-FORMAT (best to use a magnifying glass unless you have 20 / 20 vision, or "young eyes"). The relevant dip switch is # S420. This is a 3-position, sliding dip-switch. The 3 positions are: (1) 1.001, (2) REMOTE, and (3) 1.000). In NTSC countires like the US, the CCU's are normally set to 1.001 which provides the 0.1% offset which makes 24 into 23.976, 30 into 29.97, 60 into 59.94 etc. If you set this dip switch to its center position (= REMOTE), the frame rate can now be adjusted remotely using the MSU-750, or similar (aka "paintbox").

On the MSU-750, press the button labeled, CONFIG, down the left side of the touch screen. Then touch CCU, and in the next menu touch, MULTI-FORMAT. Next, select 1.001. Then set OUTPUT 1 to the desired frame rate, typically 59.94 interlaced for a simulated slow-motion effect generated later in post. I'd also set up OUTPUT 2 the same way, so there are no mistakes (as it depends on what outputs you are using on the back of the CCU). So for safety's sake, set up both outputs to the same frame rate.

If you need the Security Code to get into the Engineering mode of the MSU, contact the rental house supplying your equipment.

As configured above, note that the camera will now only shoot 4:2:2 instead of 4:4:4, Interlaced instead of Progressive, and after the post effect is performed, the picture resolution will be half of what it is normally.

I've been advised to shoot pseudo slow-motion effects like this as pure 60.0 interlaced if possible. But the SRW-1 deck does not allow shooting pure 60.0, so this means you have to shoot 59.94 interlaced as the only high-speed option in a typical set up with a SRW-1 recorder. I believe there is a small chance of getting a periodic, or cyclic "glitch" when performing the post-generated effect at 59.95 interlaced. This is why pure 60.0 is preferred, if and where possible.

If you change the framerate to an "off speed" setting, please remember to change the frame rate back on the MSU-750 to the appropriate setting for normal shooting later (or to whatever you next frame rate will be). For most useser in the US, this will be 1.001 and 23.98

As far as I know, changing the frame rate in the F950 camera itself (in the Maintenance Menu) has no effect what so ever while the camera is connected to the CCU. In other words, the Sony HDCU-F950 overrides the camera, and therefore takes control of this setting. But if the camera is disconnected from the CCU, then you would need to set the format and frame rate in the camera itself.

For any off-speed shooting, please remember to load a fresh tape into the relevant deck (or decks). As is customary, all off-speed material should be recorded on to a separate tape (clearly labled, of course). If you change the off-speed frame rate within an "off-speed" tape like this, provide at least a 30 second pre-roll at the head of each frame-rate-change sequence.

Additional notes for setting up Frame Rates in the CCU (Sony HDCU-F950).

Board AT (Multi-Format Section)

Micro switch S-420: Left Hand position: 1.001 (for 59.94 etc.) / Center position: REMOTE (for control via MSU) / Right Hand position: 1.000 (for pure 60.00 etc.)

Micro switch S-418: Left Hand position: 60 cycles / Center position: 50 cycles / Right Hand position: 48 cycles

Micro switch S-419: Left Hand position: Interlace / Center position: Progressive / Right Hand position: 540p

Examples of "hard" setting the format and framerate:

(A) For 23.98PsF set switch S-420 to 1.001, set switch S-418 to 48 Cycles, and set switch S-419 to Progressive

(B) For 24.0PsF set switch S-420 to 1.000, set switch S-418 to 48 Cycles, and set switch S-419 to Progressive

(C) For 59.94i set switch S-420 to 1.001, set switch S-418 to 60 Cycles, and set switch S-419 to Interlace

(D) For 29.97PsF set switch S-420 to 1.001, set switch S-418 to 60 Cycles, and set switch S-419 to Progressive

(E) For 30.0PsF set switch S-420 to 1.000, set switch S-418 to 60 Cycles, and set switch S-419 to Progressive

(F) For 60.0i set switch S-420 to 1.000, set switch S-418 to 60 Cycles, and set switch S-419 to Interlaced

Note: Needs checking, but I don't think the Sony SRW-1 / SRPC-1 HDCAM-SR Field Recorder accepts any pure 30.0 or 60.0 signals, so (E) above would be an un-recordable format, as is (F) pure 60.0 interlaced. So make sure any settings made in the CCU are formats the recorderer can actually record.

REMOTE Position:

Setting switch S-420 to the Center / REMOTE position, will allow for frame rate selection to be made using a MSU or "paintbox" (e.g. MSU-750).

(1). Select MSU Panel Active

(2). Select CONFIG, then CCU

(3). Select Multi-Format

(4). Select Output #1 {Available Frame Rates will be displayed}

Disclaimer: While I check the information presented here as thoroughly as possible (...through actual work experience, personal testing, and consulting other experts in the field), I can not absolutely guarantee its complete accuracy. These writings really reflect my own evolving understanding of these particular issues as I try and piece everything together myself. These pages are works in progress, and will be corrected and updated as new information comes to hand. Any and all feedback is very gratefully accepted. Especially any information that helps to correct outright mistakes in this presentation, or additional information that helps to expand the scope of these discussions.

Peter Gray
(in California)
P.O. Box 5132
Pine Mountain Club, CA 93222
United States of America
telephone: +1(661) 242-1234

dp@petergray.org