September 15, 2014, 12:05:28 AM

Author Topic: Patent: A Pellicle Mirror by Canon  (Read 9169 times)

dilbert

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 2872
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #15 on: October 31, 2013, 05:05:41 PM »
Fixed mirrors were a dead end then (EOS RT).
Fixed mirrors are a dead end now (Sony SLT).
Canon: stop f*cking around and bring those mirrorless cameras!

Canon doesn't know what it needs to do to innovate and get consumers to buy so it is copying others now...

canon rumors FORUM

Re: Patent: A Pellicle Mirror by Canon
« Reply #15 on: October 31, 2013, 05:05:41 PM »

Dylan777

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3985
    • View Profile
    • http://dylannguyen.smugmug.com
Re: Patent: A Pellicle Mirror by Canon
« Reply #16 on: October 31, 2013, 06:02:40 PM »
Is this going to make the body smaller to compete with the mirroless systems?
Listen, Canon... if you're reading...unless its going to make OVF better and not just smaller... don't waste your time. Unless you're going to cram more tech into the current bodies...

Think of it this way... not everyone wants small mirrorless cameras... its small and its cute, but thats about it.
Its like a Mini Cooper, not everyone wants one... similarly not everyone wants a Hummer either, but there is no point in making your entire product line into a mini cooper. If anything be like Toyota, have the yaris, corrolla, camry, RAV4, 4Runner, etc.

Wrong. Image quality is everything. If cameras can be made tiny without losing IQ, then go for it.

Who wants to drag around on big heavy bulky S___ if it isn't really necessary?

The only reason to why I'm still shooting DSLRs is because of the IQ. Sony's new A7R (tiny FF body) might replace my canon bodies permanently.

Until your subject running ;D

Can't wait for my a7 + zeiss 55mm to arrive.
Body: 1DX -- 5D III
Zoom: 24-70L II -- 70-200L f2.8 IS II
Prime: 40mm -- 85L II -- 135L -- 400L f2.8 IS II

gmrza

  • 6D
  • *****
  • Posts: 497
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #17 on: October 31, 2013, 06:12:11 PM »
One big advantage of a fixed mirror system is that you can get a much higher frame rate while being able to see the subject during exposure.

For these reason I loved my EOS RT - actually *seeing* what you shoot makes a huge difference and even on digital would save me lots of "did it blink?" looks at the lcd screen.

Another big advantage of the non-flipping "mirror" design is the ultra-low shutter lag - with the EOS RT you just have to touch the shutter, and it has taken a picture before you realize what's been going on.

With the advances in high iso capability imho this would be great for sports/wildlife shooters as the reduction in light that reaches the sensor doesn't matter that much as on film ... or of course mirrorless and an evf.

I think everyone is missing one part: The Canon patent seems to be about a mirror with variable reflectance/transmittance.  That is different, I believe, to the Sony system.

What is also being forgotten is that a patent is no guarantee of a product based on that patent.
Zeiss Ikon Contax II, Sonnar 50mm f/2, Sonnar 135mm f/4

marceloshak

  • Power Shot G16
  • **
  • Posts: 24
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #18 on: October 31, 2013, 06:15:11 PM »
....Plus Eye-Control Focus v.2.0...
+1 I miss the focus eye control of my EOS 3 and EOS A2e...

Bennymiata

  • EOS M2
  • ****
  • Posts: 199
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #19 on: October 31, 2013, 07:13:55 PM »
I agree with gmrza.
If you look at the drawing and read the words, it does seem that Canon are talking about a mirror that can change its reflectiveness electronically.

When looking through the OVF, the mirror reflects most of the light into the prism, and when you press the shutter, the mirror goes almost clear meaning that most of the light WILL go to the sensor.

It's basically electronic mirror lifting but instead of the mirror going up and down, it just goes clear when required.
A bit like the electronic LCD glass you can get now where at the touch of a button, the glass become opaque.
This is similar, but the glass becomes either clear or reflective depending on the position of the shutter.

pharp

  • Guest
Re: Patent: A Pellicle Mirror by Canon
« Reply #20 on: October 31, 2013, 08:21:35 PM »
I agree with gmrza.
If you look at the drawing and read the words, it does seem that Canon are talking about a mirror that can change its reflectiveness electronically.

When looking through the OVF, the mirror reflects most of the light into the prism, and when you press the shutter, the mirror goes almost clear meaning that most of the light WILL go to the sensor.

It's basically electronic mirror lifting but instead of the mirror going up and down, it just goes clear when required.
A bit like the electronic LCD glass you can get now where at the touch of a button, the glass become opaque.
This is similar, but the glass becomes either clear or reflective depending on the position of the shutter.

Thats my interpretation, but the biggest problem I see - there is NO way that adding an additional element (mirror) can do anything but hurt IQ. Only question - how much.

Normalnorm

  • EOS M2
  • ****
  • Posts: 172
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #21 on: October 31, 2013, 09:06:20 PM »

Sony's SLT is very different from the Canon film pellicle mirror cameras.

Canon had a semi-translucent mirror to direct half the light to a viewfinder, and the other half to the film - the upshot is no mirror slap, so higher frame rates are possible and also a more stable camera, and also no viewfinder blackout. The downsides are a darker viewfinder and less light hitting the film.

Sony use the same type of mirror to redirect half the light to a dedicated AF chip, and the other half to the sensor - there is no OVF. So its basically a mirrorless camera in a big body and only half the light sensitivity it should have. A mirrorless camera with on-chip PDAF is much more sensible if you're going to dispense with the OVF - which is precisely what the A7 and A7r are all about.

This new Canon patent is almost a digital version of the film based Canon pellicle mirrored cameras, but with one major difference - the mirror has variable reflectance/transmission. If it could approach 100% reflection while composing, you've got pretty much a conventional bright viewfinder, and if it could electronically switch almost instantly to almost 100% transmission, pretty much all the light can hit the sensor for the shot.

Much higher frame rates, much shorter shutter lag, and no vibration due to mirror slap could be on the cards.

IIRC Sony claims only a 1/3 stop of light lost by the mirror. Apparently only a enough light to work the PDAF. The bigger issue for some was the ghosting and random artifacts that occur in some lighting situations.

canon rumors FORUM

Re: Patent: A Pellicle Mirror by Canon
« Reply #21 on: October 31, 2013, 09:06:20 PM »

Woody

  • 6D
  • *****
  • Posts: 562
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #22 on: October 31, 2013, 10:09:25 PM »
For those of you who think that mirrorless cameras are the future and Canon does not know what it's doing, think again.

Look at CIPA worldwide camera shipment numbers from http://www.cipa.jp/english/data/dizital.html

a) In 2012, for every unit of MILC shipped, 4.1 units of DSLR are shipped.
From Jan-Aug 2013, for every unit MILC shipped, 4.9 units of DSLR are shipped.

b) When the numbers (shipment ratio of DSLR:MILC) are analyzed on a regional level:
Japan 1.25 (2012), 1.8 (till Aug 2013)
Americas 6.75 (2012), 9.9 (till Aug 2013)
Europe 5.5 (2012), 9.6 (till Aug 2013)
Asia 3.44 (2012), 3.37 (till Aug 2013)
The rest 2.3 (2012), 3.8 (till Aug 2013)

Appears that sales of MILCs are losing steam quite rapidly in America and Europe. Even within Japan, there is a loss of interest in MILCs!

Clearly, the masses are not buying into this silly EVF thing. My one year of experience with OMD taught me the same thing.

Hence, I think a pellicle mirror with electronically adjusted reflectivity/transmittivity is excellent! Combined that with on-sensor PDAF and we have a possible winner. My only concern is whether viewfinder blackout still occurs with this electronic adjustment of pellicle mirror reflectivity. In principle, it should be possible to switch this reflectivity quickly enough to minimize viewfinder blackout.

Don Haines

  • Canon EF 300mm f/2.8L IS II
  • *******
  • Posts: 3156
  • Posting cat pictures on the internet since 1986
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #23 on: October 31, 2013, 11:24:24 PM »
Please explain to me how adding a partially reflective surface into the optical path, and at an angle to boot, is going to improve image quality?

This is a bad idea. Period.

And to those of you saying how bad mirrorless is because sales suck compared to DSLR, just remember a few short years ago when people were saying that digital would never be replace film.....

Time marches on..... but how much progress have we seen in shutters and mirrors? My first SLR, an Olympus OM-1, bought used in 1975, has pretty much the same shutter as a 1DX.... yes, the shutter speed is faster and we now have "silent shutters" but it really has not changed in those 38 years...

Mirrorless offers the potential for no shutters.... and no mirrors (duh!)... a truly electronic camera... no separate focus sensors that need calibration (AFMA vanishes and the nightmare ends), a view that adjusts to conditions, zooms in to check on manual focus, and is customizable to what each user wants..... flexibility that an optical system can never have....  Are they there yet? No! But they are getting closer and how long will it be until EVF is superior to optical....

You should look a bit outside of the DSLR world to see what else is happening, particularly in low light... The latest version of night-vision goggles are staggering! Aerial surveillance platforms where you can auto-track a person walking on a dark street at night from 20,000+ feet from a plane bouncing around so much that half the crew got airsick.... I have a p/s camera that recognizes people and can auto-tag names to faces.... and in "cat mode" will take pictures of a cat, yet will not trigger on a dog ( and the opposite for dog-mode)....  these are not trivial tasks.... that p/s camera has about 100 times the computing power of a 5D. That p/s camera is vastly superior to the NASA computing center that sent Apollo to the moon!

My money is on mirrorless.....
« Last Edit: October 31, 2013, 11:27:55 PM by Don Haines »
The best camera is the one in your hands

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8608
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #24 on: October 31, 2013, 11:28:07 PM »
Canon had another patent a couple of years ago that made a mirror film that was thinner and not subject to ghosting.
 
The patent is the result of research done 3-4 years ago, some seem to think it was done yesterday.  It takes years for research to turn into a patent.
 
The dual pixel tech has worked out pretty well, if Canon can improve the next generation of it, maybe the mirror will go away.  However, the lenses won't get any smaller, and there is still the EVF that many do not like.  EVF's are improving, but are still far from ideal, particularly with moving subjects.
 
Then, as noted, MILC are fading out.  Nikon says it overestimated the market and will concentrate on DSLR's, while Canon is still wanting a breakthrough technology before committing hundreds of millions of dollars.
 
Sony seems to drop camera lines after 2-3 years to try something new.  I'm not sure this inspires confidence in their long term viability.

Woody

  • 6D
  • *****
  • Posts: 562
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #25 on: November 01, 2013, 12:40:40 AM »
And to those of you saying how bad mirrorless is because sales suck compared to DSLR, just remember a few short years ago when people were saying that digital would never be replace film.....

My money is on mirrorless.....

I am not aware of anyone saying digital would never replace film. If there were, those folks definitely belonged to the 0.001% minority. In fact, the day digital cameras appeared in the market, many folks already knew film was dead.

The landscape of interchangeable lens cameras will certainly change. But no one knows what the future is going to bring. Current MILC technology is certainly not good enough. The masses have spoken with their wallets and that is louder and far more convincing than anything you and I have to say on the web.

Timothy_Bruce

  • Rebel T5i
  • ****
  • Posts: 117
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #26 on: November 01, 2013, 05:22:07 AM »
Now I think I see all this coming together.
A translucent mirror on its own makes something like the sony dslr possible, but they don't have OVF.
In the "classic" canon dslr there is the secondary mirror reflecting light down towards the AF-sensor, so just a translucent mirror would not be possible in connecting with the current AF-systems. (The secondary mirror would be in the lightpath towards the sensor)
But in connection with the new dual-pixel AF it all makes sense!
The variable translucent mirror provides light for the OVF and Sensor ( with its ability for good phase-detection AF).
An can when necessary provide more or less light for one of them by cutting the light towards the other.

Outdoor sports cenario: 50% OVF 50% Sensor 1 stop light loos for Sensor but that us not a problem with good light (or today's ISO ability )
Super fast frame rate ( not limited by the mirror system) and no viewfinder darkening at all.

Low light cenario: for the capture the mirror directs all light towards the sensor or for a short time for better AF or towards the OVF for MF




« Last Edit: November 02, 2013, 02:32:03 AM by Timothy_Bruce »

Ruined

  • 5D Mark III
  • ******
  • Posts: 626
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #27 on: November 01, 2013, 08:27:13 AM »
This is a compromise to reduce size, it probably will reduce image quality a bit though not much.  However, the target market for smaller cameras generally does not have paramount quality as the #1 concern, size is the #1 concern for said market.  The advantage is that it could use existing EF-S lenses, so this could be a replacement to the Rebel SL1 for instance.

canon rumors FORUM

Re: Patent: A Pellicle Mirror by Canon
« Reply #27 on: November 01, 2013, 08:27:13 AM »

Mt Spokane Photography

  • Canon EF 600mm f/4L IS II
  • ********
  • Posts: 8608
    • View Profile
Re: Patent: A Pellicle Mirror by Canon
« Reply #28 on: November 01, 2013, 12:51:49 PM »

And to those of you saying how bad mirrorless is because sales suck compared to DSLR, just remember a few short years ago when people were saying that digital would never be replace film.....


A few years ago, buyers were flocking to digital and sales proved it.  Its true, some entrenched individuals at Kodak did not believe it would happen, they refused to believe in the sales figures.  They put their money on film.
 
Check the sales figures, its a fact, mirrorless sales have tanked!   Once buyers find that they have the same large lens and the little bitty camera with lousy EVF, they go for a DSLR.
That does not mean they are bad cameras, just that they are not ready to take over the market from DSLR's , and the hype turns out to be over stated. 

pharp

  • Guest
Re: Patent: A Pellicle Mirror by Canon
« Reply #29 on: November 01, 2013, 12:56:04 PM »
I think there is a common misconception that the only reason for making a MILC is to decrease the size - WRONG! As noted by others, there are many good reasons for ditching the mirror/pentaprism - inevitable IMHO. The problem to date, as I see it, there just haven't been any really compelling 'system' cameras available. If canon made a mirrorless 6D - size, etc being the same with a really good EVF - I think it would sell in droves. I'd buy one tommorrow.

canon rumors FORUM

Re: Patent: A Pellicle Mirror by Canon
« Reply #29 on: November 01, 2013, 12:56:04 PM »