Mitch Gross
Well-known member
- Joined
- Nov 7, 2007
- Messages
- 3,657
- Reaction score
- 0
- Points
- 0
Eliminating skew issues and strobe-sync issues does not necessarily mean going to a global shutter. A rolling shutter can be used and the Phantom does it today. RED can do it as well and likely will in EPIC.
Skew is s result of slow write/read speed across the sensor. Speed up the process and with each frame you have a tiny bit of time as the lines begin charging, a whole lotta time as every photosite accepts light all together, and then a tiny bit of time again as the lines all discharge out.
Strobe sync is easy as well. just need to sync signals: one to state when each frame starts the charging cycle (this is important for absolute sync on such systems as motion control and 3D) and another to note the exposure duration in pulse form (industry standard is a 5 millivolt pulse IIRC). The sync pulse can be set to trigger dead in the middle of that long time the whole frame is getting exposure, and there would never be a sync issue again with strobe lights. And if the read/write cycles were quick enough then there would be no problem with skew or other motion-related issues, such as harmonic vibrations in car and helicopter shots. This is especially important in composite shots, like just about ever car commercial made these days (well, before the economy imploded).
Skew is s result of slow write/read speed across the sensor. Speed up the process and with each frame you have a tiny bit of time as the lines begin charging, a whole lotta time as every photosite accepts light all together, and then a tiny bit of time again as the lines all discharge out.
Strobe sync is easy as well. just need to sync signals: one to state when each frame starts the charging cycle (this is important for absolute sync on such systems as motion control and 3D) and another to note the exposure duration in pulse form (industry standard is a 5 millivolt pulse IIRC). The sync pulse can be set to trigger dead in the middle of that long time the whole frame is getting exposure, and there would never be a sync issue again with strobe lights. And if the read/write cycles were quick enough then there would be no problem with skew or other motion-related issues, such as harmonic vibrations in car and helicopter shots. This is especially important in composite shots, like just about ever car commercial made these days (well, before the economy imploded).