pellicle mirror?

jacobsen1 wrote in post #10739789
that math doesn't add up, there'd be nothing left for the image?

the mirror passes some light to the sensor/film, and reflects some up. What's reflected THEN gets split between the AF and viewfinder. I'd imagine what we're using now also splits what's getting reflected anyway, otherwise how could the camera AF while we're looking through the viewfinder? So that ratio would likely be unchanged, but the ratio of sensor -vs- reflected would need to still be set.

edit: I see what you're saying now, I think we're saying the same thing.

Canon as of now uses a normal mirror, so everything goes the sensor at exposure. Sony, with a pellicle, can send however little or much it wants to the sensor (which is the same amount as it gets for exposure), it just depends on how bright or dim they want the VF to be.

Sony could send 1/3 to the sensor and 2/3 to VF (or whatever fraction, biased to the VF), which is what I think Canon did with the RT and 1N RS, but then you're losing 2/3 stop, not 1/3 like you said in the OP. Or they could send 2/3 to the sensor/AF/exposure (1/3 stop loss, like you said) and a dark VF, or compromise at 50/50, or get rid of the VF entirely....

Basically I'm saying the loss won't necessarily be 1/3 stop. If they imitate Canon, it'll be 2/3. If they forget the VF, there won't be any, etc.

Personally none of the advantages that a pellicle mirror offers appeal to me, I'd rather have the extra 1/3 of a stop, no glass between the sensor and lens and a brighter viewfinder. Viewfinder blackout has never bothered me and I'm fine with the 5 or 6 fps that my camera offers, plus I'm not a video guy. The only things that could be a plus is it could end up cheaper and more durable due to less moving parts but that remains to be seen.

There may be a few areas where I'd like the advantage of the pellicle but the disadvantages outweigh the advantages for what and how I shoot. Every bit of light I can get on the sensor, the better.

Wouldn't AF suffer from using a pellicle? Right now, the light coming in goes to the view finder and AF-system. With the pellicle, both of those are going to have to suffer since some of the light has to pass directly to the sensor.

Then there's the fact that you're sticking yet one more piece of glass in-front of the sensor.

The mirror is already partially silvered so that light can pass through to the AF system. The viewfinder is already dimmer than it could be, check an old manual focus body and you'll see how big and bright it can be with a solid plank of glass good old fashioned mirror that sounds like a door slamming shut when you take a picture

jacobsen1 wrote in post #10739679
here's the definition:
Single Lens Reflex. This term designates a type of camera which incorporates a viewing system where the subject is seen through the lens. This image is reflected on a mirror and passes through a prism that restores the normal view. Interchangeable lens 35mm cameras are mostly of this type. ...

no mention about it moving, just that it's a mirror...

i don't know what definition you're citing, but every reference i've seen of the term describes the "reflex" as the movement of the mirror.

not that it matters a whole lot, as most people still use pellicle mirror cameras the same way they use SLRs.

alt4852 wrote in post #10743520
i don't know what definition you're citing, but every reference i've seen of the term describes the "reflex" as the movement of the mirror.

not that it matters a whole lot, as most people still use pellicle mirror cameras the same way they use SLRs.

Ever hear of a twin lens reflex camera? Note the term 'reflex' in there too! There is no moving mirror in that design, just a mirror for the viewfinder lens and no mirror in the path from the photographic objective lens to the film (only the shutter is in the way).

phigment wrote in post #10743610
Ever hear of a twin lens reflex camera? Note the term 'reflex' in there too! There is no moving mirror in that design, just a mirror for the viewfinder lens and no mirror in the path from the photographic objective lens to the film (only the shutter is in the way).

yea, i've actually always wondered about that. there is no reflex movement, and the light is not directed in a reflexive manner either.

I would LOVE this. !! This is exactly why I shot the EOS RT when I was a film shooter. That is the one of the 2 features I miss from my film days. The pellical and the split prism.

alt4852 wrote in post #10743665
yea, i've actually always wondered about that. there is no reflex movement, and the light is not directed in a reflexive manner either.

Reflex means reflection, not a 'reflex' action to move the mirror.

Mark1 wrote in post #10743786
I would LOVE this. !! This is exactly why I shot the EOS RT when I was a film shooter. That is the one of the 2 features I miss from my film days. The pellical and the split prism.

The split prism you can do today! Get a 1D and an EC-B screen. Aftermarket splits are available for the 5D, 40D and 50D and even 7D I think though splits mess with the metering.