I sort-of assumed the A900 shutter sound would be similar to the A700 but it's quite a bit different. http://www.youtube.com/watch?v=qamhsxYTejk&feature=related there are also some recorded shutter sounds from the 1D and D3, D700 etc. cameras.
Greg

Very cool Greg. I have to admit, I love the sound of my a700's shutter, until I am trying to photograph one of Ian or Emma's band concerts, then it sounds so loud that I am afraid that everybody in the auditorium can hear it as well as I can!hiccup!

It would be great if Sony could make a couple of prime lenses with leaf shutters then we could just about have a silent shutter, the only problem would be that the FP shutter would still have to open and then close at some point, so there would always be some noise no matter what I guess. (And actually the A700 shutter is one of the better ones I thought).
Greg

Greg.. You've got me wondering... If Sony were to make a leaf shutter in lens... Could the camera be programmed to keep the focal plane shutter open when a leaf shutter lens was attached, and kill power to the sensor to act as a shutter of sorts for changing frames??? Does that make sense, or am I talking nonsense??

Yeah I was just thinking the same thing, if the leaf lens was attached it could command the camera to open the FP shutter but leave the mirror down (wishful thinking maybe, because then the sensor would be exposed to light coming in around the edge of the mirror, but the sensor doesn't have to be 'on' in an A700 until the shot anyway, like it does in some of the LV cameras)...the act of pressing the lens release button to uncouple the leaf shutter lens could then close the FP shutter..back to normal operation again. Haw! it's a case 'for' an OVF and mirror system type camera, (DSLR) but I suppose the DSLT's could be made to work as well, because in those the FP shutter is always open in any case; those would just have to be prevented from operating the FP shutter to take the shot and use the Leaf shutter instead.
Greg

He-he...

The mirror flip sound is louder than shutter, even with a700, leave alone the a900. You may check it with the 2sec delay.

Then there's the lens aperture clank that may be very loud, depending on the lens used. You may check that with the DOF preview.

Silent shooting really needs smooth aperture video lenses and an electronic shutter. Some future Nex may hold the key to silent shooting.

Thpoil thport agorabasta , but yeah you're right the mirror does make most of the noise, I was forgetting, I was thinking later about the Bronica mirror/shutter, it makes quite a thump being so large, but if you engage the MLU lever before the shot (tripod required) and then press the shutter button the Seiko in-lens leaf shutter makes a sound so small you can just hear it and I was thinking how nice it would be for us to have the same now in FF especially, if Sony brings us a 35MP FF camera at some point.
Greg

Oh well Greg... Another great idea smashed on the rocks of reality...

Exactamundo John, mores the pity, but the really irksome thing is (don't tell anyone...mums the word) the DSLT design is quite ok for this quiet shutter idea....ghaaaaa
Greg

OK, Greg,

But you still need to somehow accommodate smooth aperture lenses at the A-mount - requires quite a bit of tinkering. Upon that, you're free to go.

And then they may change the mirror so that it reflects only the IR; and then PDAF off that IR only, while allowing a fallback to main-sensor CDAF if the PDAF fails. An electronic shutter still is a must, though.
That would be a near-perfect SLT - no light loss at the mirror, no parasite reflections, greatly reduced PF, silent, etc., etc...

But one can only dream...

I guess if they were to build a few 'hypothetical' leaf shutter lenses not just for studio commercial stuff but also candids they would need to have a greater shutter speed than 1/500sec that a lot of them seem to be limited too..so yes a digital shutter would be good and that wouldn't make much noise either... then you wouldn't need the FP shutter anymore anyhow.
Greg

Could one even make a mirror that would reflect IR, yet let visible light through without too much loss?? All in all, I think I'll just buy a blimp for my a700!

Yeah me too, I would have thought that the gaps in the nanoreflector would have to be 700nm at least to catch and reflect some IR and then that would block visible light as well....I think, but who knows maybe they have some other way, photons are very strange cattle.
Greg

A mirror that reflects IR yet lets the visible light through is found in every digital camera. That's the IR filter. A thing also culpable for the purple fringing.

Then Sony already filed a patent for an SLT design that has the IR filter exactly on the mirror.

Reflects or absorbs??? Could a filter be made to reflect IR to guide it to a PDAF array, with sufficient intensity for focusing, and still let ambient light through? Forgive me if I am naive on this.. John