Replies to This Discussion

Permalink Reply by Chris Maytag on May 14, 2013 at 5:39pm

I think we will continue to see dome resolution measured in simple pixels (4K, 8K, etc). The reason is that for an observer in the theater (let us assume this observer is in the middle of the theater, for clarity), it is the total number of pixels and the *angular* size of those pixels, rather than the density of them, that determines perceived resolution. An 8K dome master, or instance, would appear to be of the same resolution on a 10 meter dome as it would on a 20 meter dome (assuming you adjusted brightness appropriately) because the angular size of the pixels would be constant in the observer's view.

• ▶ Reply

Permalink Reply by Srikanth Peddibhotla on May 14, 2013 at 9:37pm

Chris,

Hmm, you may be right! Thanks for sharing your thoughts.

• ▶ Reply

Permalink Reply by Matthew Mascheri on May 26, 2013 at 11:14pm

One other thing to consider Srikanth, is the resolution of the content vs the number of pixels projected on to the dome. Just cause you have 4096x4096 domemasters doesn't mean that all those pixels are actually shown on the dome.  Between slicing, encoding and projector blend, you are looking at loosing some pixels.

Matt

• ▶ Reply

Permalink Reply by Chris Maytag on May 27, 2013 at 9:14am

Yep, we've had some minor difficulty communicating the difference between not only content pixels vs. projected pixels, but also the difference between (effective) projected pixels and "total pixel count in the projectors being used," a mistake made more than once by people talking about our current 8k remodel. Have also seen "Sixty-four million pixels!!!" (from 8k by 8k...).

In reality we're dealing with a medium that, for all its progress, still necessitates a loss in both resolution as well as in color depth & fidelity. Crossbounce limits just how good the image can look, and until the screen itself can, oh I don't know, selectively reflect light, we'll be looking at images that are less saturated/too contrasty. While we render carefully made footage into beautiful 32-bit EXRs. :)

• ▶ Reply

Permalink Reply by Brian Wirthlin on July 25, 2013 at 10:31am

It's worse than just the obvious problems mentioned so far. Pixel count just tells you what the imager is capable of producing. I've seen 8 k demos where the grids looked like they were drawn in Crayon and then digitized. Lens design is hard, lens production is hard, lens packaging so everything is in the right place and expands and contracts the way you want is hard. There are lots of places to skimp, and if your business model involves convincing the customer that your system is the most "cost effective" - the last thing you want is for them to be asking the right questions…

• ▶ Reply

Permalink Reply by david alejandro toro gonzalez on October 28, 2013 at 9:11am

How can one quantify the quality of a full dome content, camera system and display system? Just  Like we have HD, FullHD , MegaPixels etc  today may be in future we will have full dome display and camera systems with probably, something like  "Pixels - Per - Volume" for example : 10 MegaPixels Per CubicMeter (MPPCM). 

Any thoughts

• ▶ Reply

Permalink Reply by Brian Wirthlin on October 29, 2013 at 11:30am

Well 1st, it's per square unit not per cubic unit. I'd suggest that pixels per minute of arc or milliradian - best case (center of field) worst case (edge of field - max oblique), and throw in the actual modulation transfer function of the lens system at several angles from on axis to the edge of field. I'd also stress the above are just two of the features that define the strengths and weaknesses of a fulldome system. Understanding the implications of a fulldome system is just the first step - and trying to boil it down to some rule of thumb is the road to the peter principle... As to the task to quantify the quality of content - in image processing one man's enhancement is another man's garbage...
 
david alejandro toro gonzalez said:

How can one quantify the quality of a full dome content, camera system and display system? Just  Like we have HD, FullHD , MegaPixels etc  today may be in future we will have full dome display and camera systems with probably, something like  "Pixels - Per - Volume" for example : 10 MegaPixels Per CubicMeter (MPPCM). 

Any thoughts

• ▶ Reply