FZ2500 Impressions and Comments?

[Mike Griffiths]

Originally Posted by Roger Gunkel

AGC, Automatic Gain Control, is very common on a lot of audio and video equipment. It is a method of reducing the chances of overloading the audio input by levelling the recording. It works by using a fast attack compression, which instantly limits the maximum level to a preset limit, usually factory set. The limiting is released once the sound source drops below the limiting threshold. The release can be quick or slow depending on how it was set, but basically brings the sensitivity back up which can lead to background system hiss being audible. You can also get a pumping effect if there is a lot of regular quick variation in the source level, such as close miking a voice or loud music etc.

The FZ1000 and probably the FZ2500 has a menu setting for switching between auto level or manual. This can only usually be accessed with the camera in manual mode. Modern camera AGC is usually quite effective in moderate sound variation situations, but is generally pretty basic and for better sound control you should leave on manual. Audio recorders like the Zoom H1 also have switchable auto gain, which in the case of the Zoom is quite aggressive with a slow release rate which is very noticeable on recordings. I always use mine in manual.

Hope that helps,

Roger

Thanks Roger, but I'm still baffeld. I put the FZ2500 on to manual video and still can't find any control that suggst AGC can be turned off. Could you help a simpleton and point me to the setting? I have been using a Sony X 70, no problem with that.I also use a Tascam audio recorder and again, no problem.
Thanks

[Chris Harding]

Hey Mike

Switch to creative video mode and then look in the video menu for "Mic Level Limiter" and turn it off!
That switches off the AGC ... remember the only control you then have prior to recording is the mic level so if the audio level increases you are basically buggered. If you want to use manual in an uncontrolled environment (unlike an interview) you will need some sort of manual level control like a passive mixer on the hot shoe ..unlike pro camcorders you don't have a physical level control!! My cam sits on an XLR adapter which splits two inputs into left and right and gives me peaking control and level control too.

If you are doing run 'n gun stuff where the audio fluctuates wildly then the limiter needs to be left on!!

[Chris Harding]

Ok we did a video shoot on the beach yesterday so here are some impressions both good and not so good.

(1) My normal MO is to focus with a half shutter press and then record. If I need to adjust focus on the FZ1000 then I just half press shutter but this is a big issue on the FZ2500 ...the shutter button is very easily pressed a tiny bit too much to refocus and the recording stops ...I did just that yesterday and lost the bride and grooms first kiss ..big bummer!!! ...However the touch screen focus is awesome (I really should have used it to refocus!) and keeps the camera recording safely without touching the shutter button!! I will know next time!!
(2) I was quite surprised with the iDynamic setting left on auto ... We were shooting straight into bright water on the beach so i did an exposure correction of 1 2/3 stops so faces looked good in the EVF ..I actually could have just let the camera DR handle it as it was a tad over exposed so the EVF doesn't actually show as good a range as the DR setting actually can give you. You can record into quite a bright background and the camera will recognise the backlighting and correct it for you. They also have a touch function for AE and it supposedly exposes for the spot on the screen you touch but it doesn't work that well with heavy backlit conditions.
(3) In really bright conditions you cannot see the LCD ... sun in your eyes and white sand is tough conditions!!) That does make using touch focus which I love hard to use but we did have extreme conditions admittedly

Overall I'm pretty happy ..slow fast focus buttons are smooth as silk and you also have a two speed zoom on the LCD so you can zoom in and out by touching the LCD and choose the speed. Nice if the cam is tripod mounted.

Haven't played with the high bitrate modes yet nor the variable frame rates or slow/fast and dolly zoom ...it's got tons of features that still need to be discovered!!

[Ronald Jackson]

I have a Carryspeed VF4 Loupe, originally for a GH4 on my FZ1000. Does make focussing in bright sunshine easier partic as I use telephoto a lot. Adds to the bulk of course.

Ron

[Paul Mailath]

I love to contribute but I'm still bloody waiting - ordered in Nov!

[Chris Harding]

Hey Paul

I did a pre-order in September!! Only got it last week! The next batch are due mid January so not long to wait!!

[Roger Gunkel]

Hi Mike,

I see Chris has answered the setting question for you, time difference meant I didn't see it until this morning in the UK.

Chris is right on the run and gun where there are constant big audio variations, you really have to leave the AGC on, but when there is a reasonably constant audio of course it is better to use manual set to allow for the highest sounds. It's more effective to choose the amount of compression you may want in post rather than relying on the extremes of AGC when you have a practical choice.

Roger

[Chris Harding]

Thanks Roger

One thing to remember is that Panasonic (like Sony) use limiters now rather than AGC so it's very unlikely that the level will rise as the circuitry only limits the peaks above the mic input gain (default is 0db which is way too much except inside a studio). The only time you will be a noisy floor level is when you cam is set to 0db so then it will still only limit (I think 8db max) At 0db a lot of ambience will still come thru and "sound" like AGC noise but it's simply allowing noise to come thru that's up to 0 db which is quite a high level. If you set up the camera with at least a -6db mic level then a lot of low level ambience is eliminated. I tend to keep my cameras at -9db so they have a lower floor level and you don't hear as much ambience as you would at 0db when no-one is talking. Try setting up the camera with your audio system (wireless mics or shotgun) and listen on headphones in a normal room and turn the mic level down to the threshold you want ...then when your audio comes thru when talent is talking into the mic you get nice audio but when they stop talking the input level is low enough to not cause the camera to send it thru to the audio channel as it's set low.

If Mike checks his FZ2500 I bet the mic gain is set at default which is 0db!!

[Roger Gunkel]

All good points Chris. I think the older cameras used a compander which expanded the audio sensitivity in low input situations, then compressed or limited it at the higher end. It always gave you an increase of noise over a couple of seconds as the expander kicked in at low input.

The mic sensitivity is also important as you mentioned. At 0db you will hear much more of the general ambient sound that may be important in many instances, but with greater compression at the higher volume end of the scale. With -6 or -9db of reduction, you will get far less lower level pickup but less compression at the higher end. Compression and limiting is very useful, but the more a sound is compressed, the more it will change in tone, as the more dominant frequencies will be compressed earlier.

One other thing to bear in mind is that a 3db increase is effectively a doubling in audible volume and of course -3db is halving. So varying audio by 6db or more is a significant change of overall volume.

Roger

[Mike Griffiths]

Chris and Roger,
Thanks so much,I have 0dB set, I'll wind it down and play with it. For plays where I know sound levels I'll switch it off, in any case my main audio is eiither into a Tascam or into my X70 via shotguns (impossible to get close so 2 XLR shotguns giving stereo into the Sony X70). The audio into the FZ2500 will be for syncing or back up. But for run and gun I'l play with -3 to -9 dB and get it set.
Thanks again.

[Larry Johnson]

The zoom function buttons are truely awesome, but I've noticed that when the camera is auto-zooming (F1) and the focal length enters the digital zoom region (light and dark blue zones), the zoom-in speed increases. Had my zoom speed set to medium and noticed the increase in those blue areas. It was nice and smooth in both areas, but on playback it was a little choppy. Don't recall what format I recorded that with. Might have been 4K. Also, the choppy play may be a result of viewing on my old macbook.

When selecting the MP4 (LPCM) or MOV recording formats the menu states that, a high performance PC is required to play or edit. Precisely what do they consider to be a high performance PC. Am I correct in assuming that a late 2008 macbook pro doesn't qualify.

[Chris Harding]

Hi Larry

I'm on PC and a i7 2600 which is a 3.4GB processor and 4K is quite choppy on zooms too. We do live streaming and the specs on our live switching software is a 6 core processor 4.00ghz machine ...A 4K image eats up CPU so even a 2008 Mac will probably struggle with the frame rate and huge file size ...If you are using really high bitrates like the 200mbps an older machine will struggle!!

Any reason why you are shooting 4K ...or just because it's there?? I'm assuming you have a 4K monitor on the mac? and also a 4K TV ....otherwise it a bit pointless. If I shoot in 4K I still render my video out at 1080 so it's usable on normal devices and the sub chroma sampling during downsizing also creates a 4:2:2 video in 1080.

If you are however watching and editing 4K thruout you will have to dig into your wallet and get a speedy new computer!!

[Larry Johnson]

Just testing 4K, although I don't have a 4K monitor or TV. I expect that I'll want to use it in the future to crop in and downgrade to 1080. That's in the future though.

Thanks for the info about bitrates. That helps. Recorded a clip this morning in AVCHD 24m/30p just to get familiar with the camera. Great quality, with VFR. Files don't download like they do with my canon. Anyone with a mac that can assist? When downloading MP4 recordings from my canon I get files, with names, that I can easily import into Lightroom. When downloading from the Lumix all I get are movie icons that can apparently only be imported into Apple's Movie software. These screenshots may help explain it better:

[Roger Gunkel]

Hi Larry,

I don't use Macs apart from the iPad, so am probably missing something here, but it looks like you are opening the files as photos rather than video. Are you not using a Mac video editing programme to view your files? For example I wouldn't be viewing my Panasonic video files in Photoshop on my PC.

Roger

[Tom Mussatto]

I'm getting very smooth zooms in 4K and 1080 up until I enter the I zoom range at which point the zoom stops briefly and then jumps and speeds up. I zoom is really only useable for me to reframe. Happens regardless of whether I'm in 4K or 1080.