What follows is a post about Lytro technology from another list I subscribe to... (informative, so thought I would share).
- - - It's a cool idea. It does trade off pixels of the sensor against the ability to focus at any distance in a single image. Here's a link to a very well-written article (by the CEO of Lytro) with some very good images which help to clarify how it works. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.163.488&rep=rep1&type=pdf or http://www.graphics.stanford.edu/papers/lfcamera/lfcamera-150dpi.pdf One could probably condense the article into a couple paragraphs, but it would be rather unintelligible, I fear. Basically you start with a huge number of pixels on the sensor -- 16 Mpx in the paper -- and group them into many tiny fields each behind its own microlens. The paper has 292×292 such tiny fields each containing somewhat over 100 pixels. That basically lets you figure out where every ray which strikes the main lens comes from (see the article). You can post-process any single image to form a perfectly focused image of any plane in the field, from very close out to infinity -- but you only get a perfectly focused image of 80,000 pixels. That's not terrible -- it corresponds to about a quarter-VGA (QVGA) image. Depends on what your needs are. If you shoot very dynamic scenes with a lot of depth of field in the scene, it can be a godsend, because you can later decide which plane to focus on. In fact, with only slightly sophisticated image processing you can make everything come out in focus. - - - My comment: the relatively low number of pixels (or conversely, the HIGH number of megapixel sensor you need to get a decent number of finished image pixels) probably makes this a technology that will need a lot more time before it is really practical for imaging larger prints. Darren Addy Kearney, Nebraska -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
