Oddities with the F3
 

Has anyone else seen the "print through" from the camera menu text when monitoring on HDMI? You can really see it if you turn the F3 gain up against a low-light background.

Also, I've noticed what "appear" to be very subtle gain adjustments being made "automatically" in low-light shooting (for example +6db or +12db). These are most noticeable when panning across a dark or mixed background to something brighter. They show up when monitoring to a large HDMI monitor, and, worse, they exist in the clips recorded 4:2:0 to cards. (Having said that, I have NEVER seen them viewing any HD-SDI output and they are not visible on the flip-out screen, even under loupe magnification). I am wondering if they are some sort of MPEG2 encoding artifacts?

Does anyone know if the HDMI port is a regenerated (e.g. de-compressed) version of what is being output by the in-camera MPEG encoder?

I have a big project coming up so I'll be comparing my camera to a couple at the dealer this week, and renting a Nanoflash or kiPro to see what's really getting pumped out the HD-SDI port.

I have turned off everything you can...no auto-white, no TLCS or AGC (well, as much as you can actually turn off TLCS on the F3). Shooting basic settings, 180 shutter, manual everything.

As much as I've never seen a hiccup in any "real" light environment, these low-light anomalies are a bit unnerving.

Re: Oddities with the F3
 

Sounds to me like your HDMI LCD is suffering from image retention, which is not unusual in older LCD panels. It also sounds like the monitor has some form of auto gain or auto contrast control. Your issues sound more like monitor issues than camera problems. Have you tried a different HDMI monitor, the fact that your not seeing these problems on an SDI monitor point to the monitor, not the camera.

The HDMI output is pre encoder, it is not post encoder, so has not gone through any compression.

Re: Oddities with the F3
 

Alister,

It's a Panasonic pro plasma monitor being driven from camera's HDMI output. The curious thing is that these "gain" changes I see are 100% reproducible. In other words, if I pan to a door from a wall repeatedly (in very low light), the "adjustment" I see happens at exactly the same place, each time. It really looks like TLCS (or something) is trying to fix something.

I was thinking it was a monitoring issue too, until I saw it happen in footage captured to an SxS card. If I import a clip, and even blow it up in my NLE, I still see the gain change, so I'm pretty convinced it's in the recorded clip.

It's weird.

B

Re: Oddities with the F3
 

Do you have auto knee on?

Of course then you would see it on SDI or flip out as well.

Re: Oddities with the F3
 

But Bob, you say you have never seen these issues on an SDI monitor or on the LCD, the only place you are seeing them is on the HDMI monitor. Plasma's suffer from burn in very easily and any auto settings on the monitor will most likely be triggered by the same circumstances being repeated. Are you seeing these issues on the NLE's monitor, or is this the same plasma screen. Try a different HDMI monitor before blaming the camera.

Re: Oddities with the F3
 

Autoknee is on by default or at least it was on my camera. I noticed it making some funky changes in the highlights as I was playing around with the iris on the lens. I would move the iris and about half a second later the knee setting would change.

Had to go in and turn that off in the picture profile I had loaded.

Re: Oddities with the F3
 

Good. Everybody should turn AUTO KNEE OFF, it reall screws up highlights. Mine is alwasy OFF and the KNEE POINT is set to 85.

Thierry.

Re: Oddities with the F3
 

Agreed, Auto Knee off. But Bob is complaining about a low light problem panning across dark areas. The knee should have no effect in this case. To me it sounds like a black level clamp or similar operating on the monitor.

Re: Oddities with the F3
 

From what I read I understood it as when he panned across to something brighter. That is why I was thinking auto knee.

Bob, can you post an example of what you are seeing?

I've not noticed anything changing other than when I had auto knee turned on.