Back to Blogging
I apologize for the long break, there were a lot of personal things that got in the way, including moving houses, a bunch of travel, and our new startup RAVN ramping up. I then had a writer’s block over having so much to write about and not knowing where to start. I hope to get to things I saw at Photonics West, SID Display Week, and visits in the UK. I also want to talk about some trends in Augmented Reality.
So, I decided to ease back into the blogging with a recommendation with of excellent article titled, “Why is making good AR displays so hard?” by Daniel Wagner, the CTO of Daqri, along with his co-authors Louahab Noui, Adrian Stannard. I will add just a few comments.
Comments on the article
The article, in particular, makes some good points about the difficulty in supporting a wider FOV. In part, they use etendue to explain why the display and optics (what the article refers to as “the projector”) must be large to support a large FOV. He also shows how large waveguides must be to support various FOVs making for a given eye relief (the distance of the waveguide from the eye).
When it comes to brightness and transparency they cite (with permission) my blog (here and here). The article uses figures from this blog to illustrate the uniformity issues found with most diffractive waveguides. He also cites this blog when discussing the issue of the display device’s resolution versus the effective resolution after the optics.
The article goes on to make interesting points about frame rate and motion blur with respect to both frame rate and duty time (how long the image stays on within a frame time).
He also makes some good points about not blocking a person’s vision, something that is exceptionally bad with the Magic Leap One (ML1)among other so-call “AR” devices (something I commented on the first time I say the ML1).
The article goes on to discuss vergence-accommodation conflict and other issues of eye comfort. I wished they had gone into more on the subject of contrast with AR, specifically, problems with contrast against the real world. What you see in the real world is the “black,” so the contrast that counts is how bright the display is versus the real world after any blocking of the light (say by the optics and with tinting).
They cover a lot in a short article and make some good points. I plan on expanding on some of the points they made in future articles on this blog.