Back in August 2010, Sony shook up the camera industry by announcing the first pellicle mirror DSLRs, the A33 and the A55. Rather than being called SLRs, the new cameras were labeled SLT, or “single lens translucent”, cameras.
Now, less than three years later, we may be seeing Sony’s big SLT experiment coming to an end. Sony’s A58 announced back in February may be the company’s last APS-C camera to feature pellicle mirror technology.
Sony has announced the Alpha A57 pellicle mirror camera, the successor to its A55 released a year and a half ago. While the sensor resolution is still 16-megapixels — no megapixel war here — the new camera has an increased ISO limit of 16,000 (up from 12,800), a faster continuous shooting rate of 12fps (up from 10), and an improved 15-point AF system with enhanced object-tracking and snappy AF during HD video recording. It can also capture full HD video at 60p, 60i, and 24p. It’ll be priced at $700 for the body only (or $800 with a 18-55mm kit lens) when it hits store shelves next month.
After damaging the pellicle mirror in his Sony A55 with cleaning fluid, a guy named Dario decided to look for a makeshift replacement while waiting for a real replacement mirror to arrive. He then discovered that food wrap (AKA Saran wrap) works nearly as well as a real pellicle mirror. The only downsides are occasionally degraded autofocus and a soft-focus effect when facing bright lights.
Image credits: Photographs by Dario/sonyalpharumors
Mike Johnston of TOP explains why Sony shouldn’t call its pellicle mirror “translucent”:
[...] “translucent” is just entirely—egregiously, blatantly—the wrong word. Translucent materials pass some of the light that falls on them and diffuse the rest. Muslin curtains, tracing paper, or frosted glass windowpanes in a bathroom are all translucent. An indistinct, fuzzy, or veiled image that’s hard to see is actually part of the definition of “translucent.” A pellicle mirror is a beam-splitter. That is, it passes some of the light transparently and reflects the remaining amount. There’s no translucency involved anywhere. Wrong word—and a bad connotation. Marketing fail? Heck, English language fail.
Wikipedia also notes that a “camera with a translucent mirror would produce an indistinct blob of light at the image plane.” A better word for people who might not know what “pellicle” means might be “semi-transparent”.
Sony’s Big Risks with the A77 [The Online Photographer]
You’ve probably read plenty of articles touting the benefits of Sony’s translucent mirror technology (e.g. high fps, AF for video, quietness, etc…), but what about the cons? One of the main downsides to having a translucent mirror is that the light hitting the sensor passes through an additional layer (the translucent mirror), which reduces the amount of light and the image quality.
Ray over at TheSyberSite attempted to quantify how much the mirror affects the resulting image quality by removing the mirror on his A55 and comparing the resulting photos. He confirmed that about 1/2 stop of light is lost, and estimates that 5% of the detail in each shot is lost due to the mirror. Head on over to the article for some side-by-side comparisons.
Secrets of the Sony A55 (via sonyalpharumors)
Here’s what the next couple weeks are going to look like in terms of press events possibly related to DSLR announcements: Nikon goes first on August 19th, Sony does theirs on August 24th, and Canon has one scheduled August 26th. Nikon will likely be announcing the D3100, while Canon drops the 60D during theirs.
A big rumor regarding Sony’s upcoming unveiling is that they’re going to be showing us the world’s first pellicle mirror system on a DSLR camera. This means instead of a traditional bulky mirror that swings out of the way — as found in current DSLRs — the Sony DSLR will have an ultra-thin and ultra-lightweight semitransparent mirror that allows photos to be shot without the mirror swinging out the way.