(SR5) HOT! The Sony Half-mirror (pellix) patent!
Design of the Pellix mirror
As you know since months SonyAlphaRumors is telling you that Sony is working on a Half-mirror (Pellix-mirror) camera. Click here to read the original rumor we posted on December 1 2009!
I remember many of you didn’t really believe in what we told you 
But now we can proove you that our rumor was true!
The very new patent from Sony (United States Patent Application 20100045853) is showing us how it works!!!
Let’s start with the very interesting part:
“There is proposed a digital camera which is capable of simultaneously performing phase difference detecting AF by a phase difference detecting AF sensor and live view in which time-series images for determining a picture composition are electronically displayed on a display”
In fact Sony invented the Holy Grail of photography (and videorecording). You will be able to use the very fast Phase-Detection Autofocus during video recording. And no more mirror blackout during still photography. No noisy mirror movements! It will make less noise than a Leica rangefinder camera!
You can read the entire patent here: http://www.freepatentsonline.com/y2010/0045853.html
Or read the part below (copied from the patent text) which summarize everything very well:
SUMMARY OF THE INVENTION
“However, in such a technology as described above, a half mirror is fixed to a camera body. Therefore, in actual photographing (in capturing a still image for record), light passing through the half mirror is used. That is, typically, an actual photographing image is generated using light passing through the half mirror at a predetermined transmittance to reach an image pickup device. As a result, a sufficient quantity of light may not be obtained in the image pickup device in actual photographing.
It is desirable to provide an image pickup apparatus capable of obtaining a sufficient quantity of light used in actual photographing in a configuration capable of simultaneously performing phase difference detecting AF and live view.
According to an embodiment of the present invention, there is provided an image pickup apparatus including a half mirror, a phase difference detecting AF sensor, an image pickup device, and display means. The half mirror separates light from a photographing optical system into transmitted light and reflected light. The phase difference detecting AF sensor receives the reflected light reflected on the half mirror to detect a focusing state by a phase difference detecting method. The image pickup device receives the transmitted light passing through the half mirror to generate time-series images with respect to subject image light from the photographing optical system. The display means sequentially display the time-series images generated by the image pickup device. In the apparatus, the half mirror is provided so as to be movable between a first position on an optical path of the subject image light from the photographing optical system and a second position to which the half mirror is evacuated from the optical path of the subject image light, and when the half mirror is in the second position, the image pickup device generates an actual photographing image on the basis of the subject image light reaching the image pickup device from the photographing optical system without passing through the half mirror.”
P.S.: Sorry if I still didn’t manage to update the SonyAlphaRumors website design. I have been really busy at work. Will have time tomorrow to make everything
Related Posts
Share
Recent comments
- Comment from sonyalpharumors | Home: [...] So was it worth to spend a Sunday ...
- Comment from sonyalpharumors | Home: [...] here). It layout looks completely ...
- Comment from Sony NEX-5 en NEX-3 - Pagina 5 - Belgiumdigital forum - Digitale fotografie: [...] de heerschappij van de traditionel...
Comment from Jeff: @ Admin: Its not totally going to be a f...
Jack
2 years ago |Nice, but not the “Holy Grail”. There is no optical viewfinder… only LCD.
popo
2 years ago |This could be the ultimate live view DSLR. Those who want an optical VF will hate it. In a quick scan of the patent, the mirror can still move for taking a shot so you don’t lose light, but I guess that can be optional if there is enough light to leave it in place.
entoman
2 years ago |I just hope that the EVF display shows the shutter/aperture ( etc ) information BELOW the scene, simulating the style of an optical finder, rather than superimposing it over the scene in the style of a compact. It would also be nice to think they could improve the EVF resolution so that it looks as sharp and clear as an optical finder, but that sort of resolution is probably at least 5 years away.
Sky
2 years ago |Sony is cooperating with Epson – and that one builds Full HD EVF so… I guess the DSLR with pellice mirror will have quite decent EVF (whatstill doesn’t change the fact that EVF is inferior to OVF, even if it’d be big fullHD)
kkt
2 years ago |I wouldn’t want anything behind the lens, considering the lack of detail in the sony cameras. 14mp a550 feels like a 10mp camera.
ZDP-189
2 years ago |Although I much admire Sony and commend its constant innovation (without which Canon and Nikon might not have brought out Liveview and video for some time) I expect this invention to produce a _less_ desirable camera.
Remember the Canon 1N? That had a ‘revolutionary’ pellicle mirror. Unfortunately, that split 35% of transmitted light to the viewfinder and 65% of transmitted light to the film. That’s not to mention the light that was absorbed or bounced around by the mirror. As a result, the viewfinder was very dark and the film speed was effectively reduced. As a result, the 1N’s pellicle mirror was retired when the 1V replaced the 1N.
How much light does Sony’s phase detection require? If the mirror saps anything like 35%, it will be a terrible loss. Sony’s cameras are already more noisy than Canon and Nikon. Less light reaching the sensor means higher sensitivity to compensate and unavoidably increased noise.
As an aside, the 1N wasn’t even all that quiet, as the shutter was noisy. Have you tried the Lumix GF-1? That’s noisy as heck, and it doesn’t even have a mirror.
Sony’s patent uses an electronic viewfinder. If it weren’t for the phase detection, it wouldn’t need a mirror at all. That mirror will limit how far lenses can project back into the body. It will also require a longer flange-sensor register. Together this means it can’t be used with many legacy lenses, a major reason for forgoing the clarity of an optical prism viewfinder.
As an aside, the 1N wasn’t even all that quiet, as the shutter was noisy. Have you tried the Lumix GF-1? That’s noisy as heck, and it doesn’t even have a mirror.
Besides, one thing that the Micro Four Thirds cameras have shown is that contrast detection does work. My GF-1 focusses a 20mm (effectively 40mm) f/1.7 lens beautifully, despite a narrow depth of field.
I don’t think Sony’s competitors will be quaking in their boots and I don’t think this patent is big news.
Sky
2 years ago |ZPD – you’ve forgot that the mirror can be flipped up resulting in no loss of image quality. It’s nothing like Canon 1N. Sony isn’t that stupid
They learn from Canon failure on this matter and patented something solving all the old issues:
1) There’s no dark OVF as you have EVF which most likely will have adjustable brightness
2) There’s no problem with sensitivity as you can flip the mirror up to get noiseless images
3) There’s no problem with taking off 35% of light as AF sensors need far less – otherwise you would have big dark spot in your OVF. Each DSLR mirror have it’s small part being half-mirror so that light could pass towards another mirror which bounces it towards AF sensors at the bottom of camera. And it takes quite low amount of light.
“That mirror will limit how far lenses can project back into the body” – it won’t limit anything as all the Sony A mount lenses don’t go into body too deeply. This problem simply doesn’t exist. We need more lenses to all Sony DSLRs – making one dedicated for a single camera like Canon did would be foolish.
“My GF-1 focusses a 20mm (effectively 40mm) f/1.7 ” – note that your depth of field is more than f/1.7… something like f/3.5 (pure guess but should be something about that) – see Micro Four Thirds article on camerapedia. There they explained it quite well
And yea, it does work, sure, only thing is about speed, not accuracy as this one is good, we all know that
ZDP-189
2 years ago |Syk,
Even Canon learns from its own failures – usually and after a fashion.
Your points 1-3:
1) Good point
2) Already noted in twitter
3) All mirrors and optics rob light. It’s a question of how much, as I said
Also, I’m fairly critical of focussing speed. The GF-1 is good. The dof was a subjective measure, based on experience with this body and lens, rather than a theoretical calculation.
As for “it won’t limit anything as all the Sony A mount lenses don’t go into body too deeply.”, you misread my point. I like micro 4/3 because I can use M39 mount, Leica M-mount, Minolta, Pentax, and many other legacy lenses. Many of these, particularly the rangefinder lenses, do not fit into a conventional DSLR body because the back of the lens extends deeply into the body and the mirror gets in the way.
“We need more lenses to all Sony DSLRs – making one dedicated for a single camera like Canon did would be foolish.” – Sorry, I don’t understand what you’re saying. Please elaborate.
Sky
2 years ago |“The dof was a subjective measure, based on experience with this body and lens, rather than a theoretical calculation.” – well, I was talking about the one you can calculate
“you misread my point. I like micro 4/3 because I can use M39 mount, Leica M-mount” – well, you are right about it, but none of DSLRs can use rangefinder lenses so you don’t loose anything you have now. Pellix mirror DSLR is not suppose to be the micro 4/3 alternative – it’s suppose to be DSLRs with video alternative.
“Sorry, I don’t understand what you’re saying. Please elaborate.” – For example Canon made a lens called 35mm f/2.8 FLP – it was a pancake which went deeply into DSLR body, and therefore couldn’t be used with flipping-mirror DSLRs. It’s primary advantage was the size – from outside it was pancake – like the one sold for micro 4/3 – but also it was very sharp at the edges. So one of advantages you could get from allowing lens going more deeply to the camera body are small, cheap wide-angle lenses… although these won’t happen (hopefully).
sonyalpharumors » Blog Archive » (SR5) Sony to announce the first two Pellix cameras at Photokina in September! The A55 and A33!
2 years ago |[...] As you may remember in February we also posted a Sony patent which shows how it works: http://sonyalpharumors.com/sr5-and-here-it-is-the-sony-half-mirror-pellix-patent/ [...]
Jeff
2 years ago |@ Admin: Its not totally going to be a fixed mirror tho, if you look at page 10 on the patent the sensor will detect whether the light exceeds a threshold, if it does, the pellix mirror stays down acting as a 1/3rd stop ND filter and the shots are taken at a super fast speed. If there isn’t enough light though, the pellix mirror will flap up, granting the normal direct-lens-to-sensor optical path.
The question is whether Sony will follow exactly as they have presented in the patent, giving the optional mirror flap up, or whether they will permanantly lock the pellix mirror in place…
Sony NEX-5 en NEX-3 - Pagina 5 - Belgiumdigital forum - Digitale fotografie
2 years ago |[...] de heerschappij van de traditionele zoeker met pentaprisma enz kunnen komen… Kevlar: zie hier… http://www.sonyalpharumors.com/sr5-a…pellix-patent/ http://www.freepatentsonline.com/y2010/0045853.html Als ik het goed begrijp, heeft Sony het [...]
sonyalpharumors | Home
2 years ago |[...] here). It layout looks completely different with current SONY DSLR body. A year ago we found the patent of the SLT cameras with the new camera design. So is Sony once again showing us a design of a future REAL [...]
sonyalpharumors | Home
2 years ago |[...] So was it worth to spend a Sunday afternoon for that? Nopoe But I always hope to find some cool stuff like I did last year when I found the translucent technology patent. [...]