Saturday, 13 August 2011

"HD" monitors for HDSLRs

There are loads of monitors out there for HDSLRs which claim to be high def. What turns out is that most of them take an HD signal but then down convert it to standard definition.
For example,

They both offer so called HD. But if you look at the actual resolution, you get just 800x400. This is not even standard PAL resolution.

In addition many Canon cameras scale down to standard resolution while filming. As far as I know it's only the 7D which provides full HD all the time.

My personal bottomline is: I rather buy a camera with a proper viewfinder than trying to find an external monitor which is sharp.

Thursday, 11 August 2011

HMI style lights

This is a film light which has about the same light output as a red-head but at only 150W power consumption. It uses a bulb which is used in HMI lights. The parts are:
- Lanzini, Alaska display light. They are the lightest and available from many places but any other for 150W MH bulbs will do.
- par 56 barn doors. They fit exactly around the light
- aluminium U shaped bar & self tapping screws (see picture below):
- Calumet rapid adapter which allows mounting the lamp on a standard tripod

Important is that the bulb has a colour rendering index (CRI) of more than 90%. The Osram Powerstar bulbs are generally best and are indistinguishable from daylight on camera. They have a colour temperature of 5200K which is the same as daylight. They work nicely as a fill against the ceiling in a INT/DAY scenario and also as a source of sunlight. If used in interior shots it is recommended to balance the camera also to daylight and wrap half C.T. blue around practical lights which are usually too bright anyway.

Wednesday, 3 August 2011

How to capture audio under Linux?

I needed to capture audio from a video running in a flash player. Here's what I did:
Created .asoundrc in my home directory:
pcm.fileout {
   type empty
   slave.pcm "tee:default,'/tmp/out.raw',raw"
   # 48000 S16_LE 2ch (aplay -t raw -f dat)
Started firefox from the command line:
FLASH_ALSA_DEVICE=fileout firefox
Converted the raw file it to a wav file:
sox -r 48k -s -b 16 -c 2 out.raw out.wav
...assuming that it's 48kHz sampling rate, 16bits and two channels stereo.