jonnyapple said:I would think it would be better for the metering system to have a uniformly silvered mirror

Aye, unless the meter was aware of its "blind spots".

The more I look the more it appears my understanding (if one can call it that) of the AF "windows" is mistaken (for the reasons you state) unless the windows are quite thin.

As for universally silvered or not, what is the human threshold of perception re:light? With audio 1/10th of a dB is subconsciously perceived, but it really takes about 1 dB (roughly a third of a stop) for conscious awareness of change. Meaning if you saw the focus screen with you ears (lol) any viewfinder unevenness of a third of a stop or less would be invisible to most all people if looking at a flat field, and likely as much as a half stop or more if looking at anything with texture.

Continuing our conversation here: http://nikonrumors.com/forum/topic.php?id=3064#post-51863

I'm certain that the mirror is silvered everywhere, but I'm not sure that the transmission is the same everywhere (It looks like it probably is the same everywhere, though). I know the mirror is silvered everywhere because the focus screen is what you see and not the AF sensor when looking in without a lens mounted. I would think it would be better for the metering system to have a uniformly silvered mirror (and no one wants a dark central area in their viewfinder). If it isn't uniformly silvered, I can tell no difference between the AF window and other places in terms of reflectance (but then, I've got eyes with a non-linear response so I don't trust myself).

Peltier.

You don't need to reduce the entire camera system temp, just the on-sensor amps. The total amount of energy in play isn't huge, the issue is that the problem heat source is often on the same die as the optical sensors, so you don't need to move the heat far to have a large effect.

My guess is that it probably will lose less than 2/3 of a stop. The higher/better ISO sensitivity will probably counter act any deficiencies to the sensor. In otherwords the slight loss of light will already be taken into account with software etc.

How would you propose actively cooling the sensor?!? Slap a cooling fan over it :^)

Remember too that this technology (Pellicle mirror) has been used by Nikon and others in the past (Re Nikon F3H).

Ahh, reading the patent the idea wasn't ever to have an optical viewfinder. Direct enough light up to the PDAF when the mirror is down, while still letting light hit the sensor for EVF / live view.

Reading the patent, I don't know what the heck the article writer is smoking, the patent clearly states the mirror moves just as in a traditional SLR. Thus the sensor gets full light for the actual photo.

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 <b>and a second position to which the half mirror is evacuated from the optical path of the subject image light</b>, and when the half mirror is in the second position, the image pickup device generates an actual photographing image

So you're taking no light away from the (main (only)) sensor. That makes a whole lot more sense. Who would want to give up a stop or more just to use a EVF?

EDIT: Now I understand what mb was saying from the get go.

right... but what percentage of the light are you taking away from the main sensor? Any light the mirror gives the EVF sensor it (plus losses (perhaps a twentieth of a stop, so insignificant) takes from the main sensor.

I'm just surprised that there hasn't been any talk re: actively cooling the main sensor so you can also use it for the EVF.

The EVF solves the problem of having a dim optical viewfinder because of the fixed mirror. It also allows for full time "live view" through the viewfinder. You can't do that with an optical VF.

Is the reflection percentage known?

And why use a pellix mirror at all if you're going EVF?

So this is just about official. Sony will introduce two DSLRs with fixed transparent mirrors. The catch is that they will have hi-rez EVF (electronic viewfinders). Might a similar tech show up (at least with this new hi-rez EVF) on a Nikon EVIL camera?

The latest rumor is now that there will be two Sony "DSLR"s with this "new" type of fixed mirror design. The A33 and the A55. The cameras will be able to auto focus as fast as a conventional DSLR but in video mode! None of Sony's current DSLRs shoot video.

Large sheets of electrochromic glass separate the locomotive engineer from the people in the panorama lounge in all 3rd-generation German high-speed trains since 1998. The driver can render these glass plates opaque if, in his judgement, something is about to happen that is not for "public consumption". Mostly, this pertains to impending suicides. The technology has been pioneered by the US-based Gentex corporation, which makes millions of adjustable rear-view mirrors. The quality of this Chinese glass does not appear to be on the level I have seen at Gentex or on the newest version of the ICE-3 trains.
The best Gentex mirrors seem indeed capable of offering an optical-quality mirror that vanishes.

Nikon had high speed Nikon F with a Pellicle Mirror for 68 Olympics 7 frames per second

Followed hi speed Canon F1 for 72 Olympics

I use to own a Nikon F2H with MD-100 until it was stolen from my apartment. It was very heavy using 20 AA batteries.

I think Sony would have a hard time saying that they are the first to use a pellicle mirror, however they probably have more funds for lawyers.

Hmmmm Nikon had years ago the F2H and F3H and also believe Canon had one on a version the F1

Electronic glass is already used in some newer design buildings

Those aren't canon engineers jonny, lol. I just posted that video to give an idea of how it works. On a smaller scale something like this COULD be used in place of a traditional flip up, flip down mirror. Instead of frosted glass like a mirrored "finish" could be used that would allow an image to be directed up into the AF sensors or viewfinder.

http://en.wikipedia.org/wiki/Electrochromic_glass#Electrochromic_devices

That 'radar blocker' licence plate cover looks a little sketchy, Niko. Are you sure you're looking into this stuff for photographic reasons?

Yes but I was referring to what Nikon could do. There was a rumor a while back that canon was working on a similar design but with electrochromic glass. I doubt that kind of technology is coming anytime soon though.

http://www.youtube.com/watch?v=qlfAgPaP5jg&NR=1

They do not intend to use optical viewfinder and light directed up is only used for AF while the image from the sensor is used for live view and displayed by EVF.
For an actual photographing mirror is moved to a second position, or up as in all SLRs.

Yeah, Yeah what does this have to do with Nikon.

It relates because Nikon and canon have used this before and might possibly again. Basically a Pellix or Pellicle mirror is kind of like a two way mirror. Instead of having the mirror flip up and down it stays put. Light can reach the sensor AND be directed up into the viewfinder at the same time. So you can have fast auto focus will shooting video. Or very high frames per second because the mirror isn't in the way.

The down side is that the viewfinder is a bit dimmer but perhaps Sony have solved that. Very interesting patent nonetheless.

http://sonyalpharumors.com/sr5-and-here-it-is-the-sony-half-mirror-pellix-patent/