Setting balanced line input on AF100

hscully

hscully

Veteran
The AF100 level meter has a line at -12 db and then a red peak at 0 db. I sent balanced line outputs out of my mixer to the line inputs on the AF100 and sent it tone from the mixer. I set the AF100 input level to -12db referencing the tone. Is that correct? My levels seemed to be 6 to 3 db low when I looked at them on the timeline in Premiere Pro, peaking at -12. I understand, from other posts that dialog should peak at -6 db. Should I set that input level to -6db instead of - 12 on the AF100 (i.e in the middle between -12 and 0)?

In the AF100 manual it says, "The recording level of this camera is set 8 db higher than Panasonic broadcasting camera recorders (AJ series products)". I'm not sure if that's helpful or even relevant.
 
Maybe that post is convoluted. Sorry :) So maybe more generally, when sending tone from a mixer to a line input on a camera, what is best level to set the camera at? -12, -6, 0db?
 
It depends what the camera metering is calibrated to.

My camera's are calibrated to -18dbfs so that 0db PPM from a mixer is line up, I then peak at +8db PPM on my mixer and that equates to -10dbfs on my camera still leaving 10db of headroom to 0dbfs.

In the USA the normal line up is calibrated for 0db PPM is -20dbfs with a peak level of -12dbfs (+8 PPM) still leaving 12db of headroom.

If your AF100 has -12dbfs as its line up for 0db then peaking +8db PPM above that will give you -6dbfs and only 6db of headroom, that is OK if you wish but it may be that the levels are too hot for broadcast use.

Best way to check calibration is to record -12dbfs tone on your camera and see if it shows the same when played back on your edit system, if it does you know that all you record will be the same but if your -12dbfs on your camera corresponds to -20 on your edit system then all they have done is re-calibrate the metering on the AF100.

Best line up would be -12dbfs but as stated panasonic might have just re calibrated their meters on the AF100, why they have done that I do not know as all broadcast cameras have -20 or -18 dbfs as their 0db reference point.

You could also see the -12dbfs as your max level from your mixer so if you send your max level and line up at -12dbfs that will still give you 12db of headroom as we have in broadcast but of course that depends on you not sending more than -12dbfs from your mixer.

Panasonics statement seem to imply that they have just calibrated these meters 8db above the normal broadcast levels so if that is true where 0db PPM line up=-20dbfs then 0db on your camera will be +8db above that and that is where the -12 comes from.

Hope that all makes sense? what meters do your mixer have as that is also relevant as the mixer meters may not be DB full scale like mine so that is where extra confusion can also occur.
 
Last edited:
Thanks, Gary. This is exactly what I was trying to figure out. Thank you for that comprehensive response.

As you suggested, I recorded tone from the mixer at the -12 db line on the AF100 and it shows as approximately -18db in the editor. So there is a difference.

Should I just punch that up over the line and leave only 6db of headroom on the camera? I can limit the mixer output to -12dbfs in that case as you say but just setting the output and leaving it alone.

Should I just go with what I have here and live with dialog peaks that land at -12 in the edit software? It all seems clean to me, just a little low. I'd like to get them up a little if I can.

I've been building out my own kit and should admit that this effort is for lower budget narrative and not professional broadcast, for which I would hire competent production sound folks.
 
Last edited:
Generally the cal. ref level standard is: 0VU on your mixer should equal -20dBFS on the camera. You can use -12, but will have less headroom. In either case, the program audio must NEVER exceed 0dB on the camera or recorder, which would likely cause audible distortion.
 
Thanks, I will definitely stay well below 0. It may be that the AF100 is not doing what is standard.

So if they say "The recording level of this camera is set 8 db higher than Panasonic broadcasting camera recorders (AJ series products)" that means that the -12 = -20 + 8 and that the -12 line on the AF100 display is equivalent to broadcast -20dbfs. Maybe?

I just wrote them so I'll report back what I find.
 
Last edited:
It may be that the have just set the meters with a different line up level that is +8 db above all the other cameras, that is fine so long as you know that but if you peak +8 db above their -12 for zero it would be illegal for broadcast use as the max level would be -6dbfs. That is Ok for location recording but it gives you less headroom that may help you out in certain situations.

It's all about headroom and if you only have 6db in hand you may run into trouble a lot quicker than if you have 12db.

Personally what I would do is us the -12 line up marker as my max peak level for location recording and if I wanted to line the mixer up withy reference to that I would send a +8db tone from the mixer and line that up with the -12 marker. That would be the same as lining up 0db at -20 and would then follow broadcast standards and give me 12db of headroom.

On a side note the -20 line up in the USA came from when sony first made DASH multi track recorders and the problem was that engineers were pushing the levels all the way up to 0dbfs and they were getting overload, sony then made -20dbfs rather than -18dbfs the line up level for broadcast so it then still gave 2db of headroom beyond what the machine meters were showing. Some camera's like my panasonic P2 onces allow you to set the headroom at -18 or -20 depending on if you wish to have 10db or 12db of headroom before the max level of 0dbfs.

A said its all down to callibration and what each meter reading corresponds to but it is worth checking it now before you start recording on location.
 
That makes sense. I'll stay with the 12 db headroom, as you suggest. Thanks for the detailed info.
 
hscully said:
That makes sense. I'll stay with the 12 db headroom, as you suggest. Thanks for the detailed info.
Click to expand...

Yes feed +8db from your mixer and line it up to the -12dbfs on the Af100 and then if you peak at +8 on your mixer you will get 12db of headroom till max 0dbfs.
 
Cool, that's what I'll do. Thanks Gary. I haven't heard back from panasonic but if I find out anything useful or interesting I'll report back.
 
Film/cinema mix levels tend to be a bit higher than broadcast with them using the full dynamic range so I suspect that is why panasonic have made their 0db reference at -12 8db's higher than broadcast.

To be honest when I mix for cinema or on-line use I tend to peak at around -6 rather than -12 but that is for final mixing and it is still better to have as much headroom as you can when recording on location just in case.
 
Original recording levels and final delivery levels are two entirely different things. When you're making the original recording on set, it doesn't matter if the final delivery will be analog or digital SD broadcast, HD broadcast, theatrical movie release, home DVD release, or whatever. The level the sounds end up at in those final delivery mixes have no relationship whatsoever to their level in the original on-set recording.

The purpose of the tone is to line up the meters on the mixer and the recording device so when you look at one you also know what the other is indicating. It is NOT to set the recording levels as such.

You need to take into account the different response to both tones and real-world signal of averaging (VU) meters and peak-reading meters. If you display a real-world signal or its test-tone mimic, a pink-noise signal, with an RMS average level of XdB on a peak-reading meter such as commonly found on digital devices such as cameras and file-based recorders, the meter will read approximately x+8 dB. Even peak-reading meters aren't fast enough to register the instantaneous level of single wave forms so the real peak value of the signal can be 2 dB or so higher than what is one the meter.

Turn on your 0VU tone and send it to the camera. Adjust the camera recording level controls so the camera meter registers that tone at -20dBFS. This aligns the two meters. From here on, don't touch the camera level controls, do all further level adjustments the mixer controls. Switch from tone to speech and adjust the mixer's channel fader so the speech registers 0VU on the mixer meter. Look at the camera meter ... when the mixer is indicating 0VU the camera meter will be bouncing at about -12dBFS to -10dBFS, illustrating the difference between real-world sounds and sinewave tones.

If you align the tone to -12dBFS in the camera and switch to speech, the real-world peaks will be 8 dB or so hotter, putting them in the -4dB range. You normally would run speech between 0 to +4dBVU indicated on your mixer's meter, so that puts your peaks in the range of -4 to 0 in the camera. And also remember that instantaneous peaks can be a couple of dB higher than the meter reads, really putting you up there tickling the clipping dragon's tail at 0dBFS. Add the fact that the talents delivery won't (or at least probably shouldn't) be a constant loudness monotone and you're asking for trouble.
 
GaryNattrass said:
Film/cinema mix levels tend to be a bit higher than broadcast with them using the full dynamic range so I suspect that is why panasonic have made their 0db reference at -12 8db's higher than broadcast.

To be honest when I mix for cinema or on-line use I tend to peak at around -6 rather than -12 but that is for final mixing and it is still better to have as much headroom as you can when recording on location just in case.
Click to expand...

Yes, that's what I'm looking for is peaking around -6 dialog peaks in the final mix. Setting the tone for -12 on the AF100, reaps -18 in the editor and so leaves my peaks around -12 which sounds fine and clean but I need to bump them up 6db in the editor to get a good mix.

The mixer I have as a fixed tone output at +4dbu.
 
Steve House said:
Turn on your 0VU tone and send it to the camera. Adjust the camera recording level controls so the camera meter registers that tone at -20dBFS. This aligns the two meters. From here on, don't touch the camera level controls, do all further level adjustments the mixer controls. Switch from tone to speech and adjust the mixer's channel fader so the speech registers 0VU on the mixer meter. Look at the camera meter ... when the mixer is indicating 0VU the camera meter will be bouncing at about -12dBFS to -10dBFS, illustrating the difference between real-world sounds and sinewave tones.
Click to expand...

I've read your post a couple of times. Great stuff. Thanks.

The setup is what got me going on this. The AF100 has a line at -12 and the note in the manual that "the recording level for this camera is set 8db higher than Panasonic broadcasting recorders" which led me to think that -12 on this camera is -20 on a broadcast camera. I just got off the phone with Panasonic and he couldn't tell me if that's correct and said he'd research it and get back to me.

It may be academic at this point but I have to say thanks for all this information. I admit a couple have blown by me but I'm really learning a ton
 
On a lot of budget cameras, I think they elevate the levels to 'enhance' the specs. At least that's my theory.
 
Well if you set the tone from your mixer at 0 and record at -12 on the AF100 and it then shows -18 on your edit system all it means is that panasonic have re-calibrated their scaling. The +4 you refer top is probably in reference to VU meters as they tend to be lined up for +4db=0VU

As I said in my original post -18dbfs is the line up that I use on my P2 camera's and that is correct for broadcast use in the UK, if I peak +8db above that it makes my max level -10dbfs which is the max level allowed for broadcast.

If I am mixing for cinema or on-line I peak higher at around -6.

to be honest I think the meter calibration is the only thing that is different here and -12 -18 and -20 are all probably all the same actual level for 0db tone at .775v
 
yes, that's what I'm going to go with. I'll stay on that -12 with 0VU. I'm going with your idea that they all represent that same absolute level. Heck, it's the only line on the display! Thanks again, Man.
 
No problems and I suppose for location recording so long as you don't go into the RED 0dbfs zone you are OK.

Must admit that I have around six different mixers now but have spent a long time re-calibrating all the PPM and VU meters so at least they all give zero line up tone to -18dbfs feeding my cameras.
 
yeah, it's good to know where you are, level reference-wise . I checked out your imdb link. Looks like you do some very cool stuff. It's a big bonus for me to be able to talk to you guys.
 
Yes I've been around a bit but look on the bright side at least we don't have to line up 24 track analogue tape machines these days and even the first music programme I dubbed digitally on an AMS Neve Audiofile The Stones in Barcelona had to be done in three parts as we only had an hour of mono storage space on the two 380mb winchester hard drives, that was only 20 years ago and look where we are now!!!
 
You must log in or register to reply here.
Back
Top