Is this stuff all drivel?

[Colin McDonald]

Below is a quote from a very intense young man on another (non-video related) forum. Having just expressed some opinions on matters within his (student) professional expertise, he then launched off on this tangent relating to broadcast video to support his view that technology had limits in replacing human operators in matters of safety. I can't make head or tail of what followed. Is this all nonsense?

... but if you want an example of silicon strain or fatigue, take a careful look at the video footage from the opening ceremony of the Olympics, a lot of the camera sensors there started suffering fatigue.

If you want one specific shot, look at the one from under the cauldron when it got turned up, the supporting staffs appeared to glow red, they where not glowing red, this was a tired sensor failing to distinguish what should and shouldn't be red and showing flares of deep primary red colour wherever light is flaring over (also an affect of rough treatment on the lens).

Cameras don't like lots of different light, especially CCD type sensors, and APS-C sensors (not used in video I must admit, but CCD devices are used).

(SNIP)

Either way, while thinking of what to write in here, a quick search of google images found these shots.

http://static4.businessinsider.com/i...the-inside.jpg
That is partly internal lighting and lighting from the flame, but it seems much brighter due to the high amount of bright flame in the shot causing damage to the sensor, this will have been replaced by RED on Saturday or Sunday.

http://www.kilburntimes.co.uk/polopo.../335827143.jpg
This is a little more difficult to talk around, but you can see the bright lights of the background being picked out more than the foreground, and if you look carefully (admittedly I was watching it live in 1080p from a satellite so it's more noticeable) you can just notice an overspill of the strong colours onto the whites, the blue on the base of Sir S Redgrave is a fair amount of actual lighting, but a lot of it is lens and sensor disruption and contamination, wish I had the comparison shots from the live show to show you the difference between a fresh and abused camera (they picked up a couple of standby ones throughout the ceremony)

My bold on the bit about commenting on video quality from a satellite.

[Charles Papert]

Last I checked, you can point solid state cameras at the sun--at least you could back in 1985, the first time I saw that technology demonstrated. Has something changed since, where pointing it at mere flames is going to cause damage?!!

[Brian Drysdale]

I suspect there could be different types of cameras being used on the OB for remote cameras as against the main OB cameras, These could have different highlight handling characteristics.

[Eric Olson]

Originally Posted by Charles Papert

Last I checked, you can point solid state cameras at the sun--at least you could back in 1985, the first time I saw that technology demonstrated. Has something changed since, where pointing it at mere flames is going to cause damage?!!

While solid state won't be immediately damaged by the sun like a vidicon tube, almost anything can be burned by the sun when placed in front of a lens or magnifying glass.

CCD sensors will bloom when they are overloaded by light. It is believable that constant blooming may create a sort of silicon strain in which the electron overflow occurs more readily. In a 3 CCD design this could affect the red sensor only, causing that one primary colour to appear where it shouldn't in the picture. I suspect things generally return to normal after the sensor has an opportunity to rest.

CMOS sensors do not bloom in the same way as CCD sensors and it is possible some of the standby cameras had CMOS designs. Obviously dirt affects lens flare as well.

While it's worth keeping the camera sensor and condition of the lens in mind, compromises often have to be made in order to get the shot. I think the coverage of the opening ceremony turned out well. It would be interesting to know what type of servicing if any the cameras required after the event.

[Brian Drysdale]

I'd be surprised if the cameras received any servicing after the opening, many could be relocated the next day at other venues until needed to rig for the athletics. If any colour channels are down in response they'll just correct with the CCUs. They'll run maintenance if a camera channel goes down, but otherwise they'll just do the standard camera set ups during the Olympics.

[Charles Papert]

Interesting information Eric, thanks. Most of that is news to me.