Originally Posted by coldmachine
Syphilis....Im afraid you are mistaken there. The performance of a machine during a credit sequence does not prove that it does not have infinite on/off. The only determinant of a standard metric is for it to be measured in the standard way, the same as all other machines.
On/Off is a very specific, and extreme test condition. Any attempt to extrapolate from that is flawed. When the Mico displays a black test screen, it was not possible to obtain a black reading. By definition, that is infinite On/Off CR. That has been corroborated by others.
I understand where you are coming from, and think that we may need to re-evaluate the way we assess CR. Having said that, I dont think its worth the effort, as newer machines will push the intra scene contrast through the roof in the near future anyway.
You overlooked a key word: Native. Mark Peterson has covered this in depth. At least within AVS over the last couple years the terminology for contrast is this:Native on/off contrast
: includes on/off, but, also is the ceiling for maximum simultaneous/intra-scene contrast. Ignoring the effect of Ansi for a moment, a CRT projector with a native on/off of 500,000:1 should be capable of close to this value when there is a small amount of light on the screen and a lot of black...for example a star field.Dynamic on/off contrast
: Current LED projectors. This also includes on/off, however, simultaneous/intra-scene contrast benefits very little from dynamic contrast. Intra-scene contrast values should be close to the Native on/off of the projector. Any improvement in intra-scene contrast is usually the result of a variable iris opening or closing (decreasing light scatter in dark scenes and opening up for brighter scenes) as well as dynamic gamma changing with the scene APL in real time.ANSI contrast
: everyone know this...worst case scenario of simultaneous/intra-scene contrast.Simultaneous/intra-scene contrast
: this value depends entirely on image content. Lots of dark/bright content will yield a value close to the ansi contrast of the projector. Lots of dark but little bright content will yield a value (ideally) close to the native on/off.
Put up a star field or a mouse cursor against a black background and I'm guessing you can see there is still light being projected in the black background, just as there is with a JVC RS35.
So, just guessing here based on the performance of other Sim units:
native on/off: ~15,000:1
simultaneous/intrascene: variable, could be as low as ansi or as high as native on/off.
dynamic on/off: Infinite