Top technology has been an important part of the Castro‘s appeal for a long time. The theater was, I believe, the first rep house to get Dolby stereo, digital sound, and DCP-compatible digital projection. I believe it’s the only local rep house that can project 70mm film, and one of only two that can handle 50’s-style,dual-strip 3D.
And now they’ve added the digital equivalent of 70mm film–4K projection. 4K projects four times the resolution of standard 2K. I’ve never seen a side-by-side comparison of the two, and I’ve heard conflicting opinions from experts on this. But I suspect that the difference is significant, especially if the film was shot in a large format and if you’re sitting close to the screen (as I usually do).
Last year, I was delighted to learn that the Pacific Film Archive had a new, 4K projector. But the PFA has a small screen–too small for an immersive experience. Not so with the Castro’s large screen.
Back in May, I wrote about a stuck pixel that marred the Castro’s digital screenings. At the end of that article, I disclosed that I had "emailed my Castro press contact about this issue, but he could only give me information off the record." Now I can tell you what he told me: that they might simply fix the problem, or they might instead upgrade to 4K projection. Today, he revealed that "We have completed installation of the 4K projector."
I am, of course, delighted.
When can you see the new projector in action? The Castro will screen Double Indemnity off a DCP tomorrow night, but that one is probably 2K (although I honestly don’t know). However, they’ll be screening The Leopard in 4K on August 24, and Lawrence of Arabia that way August 30 and September 1. Both films were shot in large film formats (Technirama and Super Panavision 70 respectively). I suspect that both films will look great in 4K projection.
Bayflicks 
Many other rep houses around the USA still have 70mm projectors and do show 70mm film festivals from time to time like in NYC and Chicago’s Music Box Theatre. Another is in Washington DC. Now the old Castro needs to replace all the nice color lights above the audience to Blue when the movie is on plus the lights under the balcony to Red/Orange for intermission and a dark Blue/Purple when a film is on. The same with the old dusty white organ grill curtains up on the left and right sides of the screen. How nice they will look with a little Blue LED light on them during a performance. Now they just turn everything off when a film starts. Time also to replace the rugs and put in a new waterfall title curtain. Charge a extra $1 for the remodel job.