Electronic shuttery

There are many situations in which acoustical camera noise is problematical (Asher has told us of his challenges in concert hall work).

Of course, non-SLR cameras avoid a major source of acoustical noise, and today we have a number of those to choose from. Still, most of our "high image performance" cameras do follow the SLR paradigm.

However, there seems no doubt but that "mirrorless" formulations for high performance cameras will shortly become increasingly available. For Canon fanciers, that may be as a new branch of the EOS platform, or it may be the premise of the "next generation" of high-performance cameras.

But that still leaves us with the sound of a mechanical optical shutter, especially when the focal plane form is used.

But there are of course the "electronic shutter" modalities. I don't know nearly enough about to what extent is fully electronic shutter operation practical (for capture of the actual image) for various sensor designs.

I'd be glad to hear the thoughts of my colleagues here on this matter.

So, Asher, there is now an EF mount for the RED Epic. Up to 120 frames/s, "every one a 'still' ".

Best regards,

Doug

Why cameras have a mechanical shutter (which for electronic viewfinder cameras, like µ4/3, Nex or Sony SLT, is noisier than a SLR because it first has to close and then open again for exposure, close and reopen so that the user gets an image on the viewfinder).

Hi, Jerome,

Jerome Marot said:

Why cameras have a mechanical shutter...

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Thanks for the link. Nice piece by Mike Chaney. Helps remind me of some things I knew once but sort of forgot!

...(which for electronic viewfinder cameras, like µ4/3, Nex or Sony SLT, is noisier than a SLR because it first has to close and then open again for exposure, close and reopen so that the user gets an image on the viewfinder).

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Well, of course whether it was nosier or not depends on the kind of shutter.

But yes, one of my cameras was a Fuji S602 (EVF), and that was what had to happen in it (but with a between-the lens shutter - actually, it used the aperture iris for that). It also used the "partially-electronic" mode for the shorter shutter times.

Thanks again.

Best regards,

Doug

Doug,

Thanks you for giving shutter noise attention. I have had 3 solutions:




May I add other "noise" types in considering shutters? I offer timing, (ie extra, uncontrolled, light) and vibration that can cause degradation of a beam being recorded at the focal plane, especial at large distances in a a huge camera.

The biggest problem for me now, using Large Format with mechanical shutters is then, not the noise, the disturbing sounds, but rather the timings and vibrations. The only current large diameter mechanical shutter is the Packard which fires at 1/25 or 1/30 second approx. So one solution is to freeze the movement by using electronic flash.

Modern, (non focal-plane), electromechanical shutters are hard to find above 90 mm diameter, can open on a few milliseconds, (ms). However, closing can take 30 to 70 ms and that is 1/30 second of continued exposure to reveal unwanted movement! The extra light allowed in the camera during this time is perhaps, 1/4 of the full aperture, but that's still ~1/100 second extra exposure.

Modern focal plane shutters are expensive. A 5" diameter focal plane shutter I looked at by Sci-in Tech costs $14,700 as the base price and the shortest exposure time is 25 ms!!! Weight is 8.2 lb!!! This might be perfect for celestial photography but out of our range earthbound humans such as you and I!

One light on the horizon for film photography is the glass electrooptical membrane shutters coming to market. However, response time to open, 90% to closed 10% is again 30 ms! Closed to open is wonderful at 1ms. These shutters add 4 major advantages:


Now for CMOS sensors, the shut off can be very rapid indeed. One can have shutters at many thousands a times per second even 100,000 times/sec with no big cost problem.

Asher

Hi Doug,

Well, of course whether it was nosier or not depends on the kind of shutter.

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Presumably the perfect shutter for a spy camera.

Regards,

stuart

Doug Kerr said:

Well, of course whether it was nosier or not depends on the kind of shutter.

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I should have been clearer. Digital cameras with fixed lenses usually have almost silent shutters. The new crowd of non SLR, interchangeable lens cameras: µ4/3 (Olympus and Panasonic), NEX (Sony) or SLT (Sony Alpha 33 and 55) use focal plane shutters. Those are quite noisy, even in the absence of a swinging mirror, because the shutter, normally open (so that the sensor gets a signal for the EVF) needs to first close and reopen after the picture is taken.

I would expect any future camera system of the kind to use focal plane shutters (for compatibility with SLR lenses) and therefore still be quite noisy.