BMPCC Noise

Have been using this camera for a while with the Kinotehnik LCDVFBM in RAW (mainly) and Prores at ISO 400 (point and shoot) and enjoying the excellent quality.

This morning I decided to hook up my Alphatron EVF and switch to Focus Assist from the Camera to the Alphatron and surprisingly got the following results....these images are taken using a Sony RX100 shooting handheld through the EVF eyepiece :-

ISO 800 at 100 percent.jpg (60.98 KiB) Viewed 2606 times

The Alphatron Focus Assist Level is set to 100%

ISO 400 at 100 percent.jpg (37.41 KiB) Viewed 2606 times

The Alphatron Focus Assist Level is set to 100%

ISO 800 at 96 percent.jpg (40.95 KiB) Viewed 2606 times

The Alphatron Focus Assist Level is set to 96%

Can only attach three images but when I set the camera to ISO 400 and the Alphatron to a Focus Assist Level of 96% it is clean on the display of the Alphatron.

If I set the camera to ISO 1600 and the Alphatron to a Focus Assist Level of 100% then the image on the Alphatron basically looks like a snowstorm.

I understand because it is Focus Assist it is blowing out individual pixels, hence they don't appear like this in the actual footage but am curious about the issue. In the past I had been using Focus Assist in the Camera and sending it through the HDMI to the Alphatron and the only time I saw noise was at 1600 so I imagine FA is set relatively low in the camera compare to the Alphatron where you can ramp it right up or drop it right back.

Am not overly bothered and see a similar behaviour with my RX100 and just want to confirm...am I just looking at noise which is coming through as blown out pixels when Focus Assist is ramped up ?

Overheating at low light settings
viewtopic.php?f=2&t=13612

Overheating at low light settings
viewtopic.php?f=2&t=13612

Yeah I don't think so, the camera was only on for a few seconds each time....also it's noise, not hot pixels.

Focus Assist isn't something I had really been using as the Alphatron allows me to focus by eye and the Focus Assist in the BMPC is set fairly low.

I was more curious about why noise appears as 'focused' pixels ?

BMPCC BMPCC BMPCC the name please...

Because it is digital noise, the name of topic in my past message isn't right.
It appears at low light settings. Pocket don't have a noise reduction built in, so I think it is a common problem to all pockets. Better that kind, than nothing at low light, as many cameras do. Use Neat Video

Because it is digital noise, the name of topic in my past message isn't right.
It appears at low light settings. Pocket don't have a noise reduction built in, so I think it is a common problem to all pockets. Better that kind, than nothing at low light, as many cameras do. Use Neat Video

Hmmm....this has really surprised me as this is nothing like what I am used to seeing :-

ISO 1600 at 100 percent.jpg (828.34 KiB) Viewed 2495 times

Am shooting RAW, Film, F2.8, 23.98fps, 1600ASA, 172.8, 5600K running version 1.6.1 and the photo is taken through the Alphatron EVF which has Focus Assist set to 100% with the waveform display on the bottom right showing what I would call decent exposure.

The Alphatron is probably more sensitive to the sensor noise.

The way focus assist works is it looks for sharp contrast as an indication of something that is in focus then highlights that. So what you are seeing is the focus assist picking up the contrast on the noise rather than the sharp edge of the in focus subject.

Ah, sorry Andrew. Yes its something other

The Alphatron is probably more sensitive to the sensor noise.

The way focus assist works is it looks for sharp contrast as an indication of something that is in focus then highlights that. So what you are seeing is the focus assist picking up the contrast on the noise rather than the sharp edge of the in focus subject.

Yeah I have to say I initially found it all a bit odd....this is a frame at 1600ASA which was taken at the same time I had the Focus Assist on the Alphatron set to 100% showing heaps of contrasty noise.

Just out of interest, was using the Pana Leica 2.8 12-35mm and when I swap it for the Pana Leica 1.4 25mm I have plenty of light and a creamy film like noise.

Blackmagic Pocket Cinema Camera_1_2014-02-13_1436_C0000_000027.jpg (177.98 KiB) Viewed 2440 times

By the way, the dots you see are simply the led's on the home theatre system.