Split Screen Fixed Yet?

Keith Wakeham · November 23rd, 2005, 01:39 PM

Quote:

Originally Posted by Silton Buendia

So we all know how the split screen effect is causes, two processors sampling the information on the chip. Half and Half and left and a right. Why not have one read every other line how things are done with interlaced video, one processor can read even lines the other odd.

What your suggesting would require a feat of engineering that doesn't exsist. CCD's have a vertical transfer register. Want to goto the next line on readout - every line gets pushed down. So the charge that was held in pixel 1,1080 is now held in 1,1079 and then next in 1,1078 all the way down to 1,0. What you want means that they would actually have to wire in 2 million more traces into the sensor so that it could skip every other line. Just can't be done without huge gaps between rows and colums so you will decrease sensitivity and increase chip size and cost.

Also, interlaced video is read out just as fast as progressive. You need to read out x number of lines in progressive in y time, but in interlaced you need to read out 1/2*x number of lines in 1/2*y time. Lines/time = some frequency. x/y = 1/2*x/1/2*y. So the ccd operating frequency for progressive and interlaced are the same thing. OR 720x240x60 fields = 720x480x30 frames. Sensor still operates at the exact same pixel clock.

Guy Barwood · November 26th, 2005, 07:54 PM

But interlaced cameras only have to read out 1/2 the number of pixels every field (1/60sec for example), where as the HD100 samples the sensor in full progressive mode at 60fps (hence the 60fps capabilities of the analogue output).

The 60fps (48/50) is used by the camera for its frame blending. Perhaps a better choice would have been to use 30fps native only, therefore halve the data read out requirements and reduce the load on their processor to be able to use a single chip solution only and eliminate SSF altogether. Was there an absolute need for 60fps?

Alternatively a slightly larger body with heat pipes could have been used to dissipate the heat of a single chip processing 60fps. What would you prefer: a slightly larger body with NO SSF altogether or the current body with the chance of SSF? Personally I'd prefer the former. While the small body is 'cute', more important is image quality in all conditions...

Jiri Bakala · November 26th, 2005, 09:04 PM

Quote:

Originally Posted by Guy Barwood

While the small body is 'cute', more important is image quality in all conditions...

Absolutely!

November 26th, 2005, 07:54 PM	#17
Guy Barwood Major Player Join Date: Mar 2005 Posts: 423	But interlaced cameras only have to read out 1/2 the number of pixels every field (1/60sec for example), where as the HD100 samples the sensor in full progressive mode at 60fps (hence the 60fps capabilities of the analogue output). The 60fps (48/50) is used by the camera for its frame blending. Perhaps a better choice would have been to use 30fps native only, therefore halve the data read out requirements and reduce the load on their processor to be able to use a single chip solution only and eliminate SSF altogether. Was there an absolute need for 60fps? Alternatively a slightly larger body with heat pipes could have been used to dissipate the heat of a single chip processing 60fps. What would you prefer: a slightly larger body with NO SSF altogether or the current body with the chance of SSF? Personally I'd prefer the former. While the small body is 'cute', more important is image quality in all conditions...