Petitioning Sony about a7R shutter shock

Lloyd Chambers just posted this on his blog.

While I agree with Mr. Chambers that shutter-induced vibration is a problem, I don’t think this is the best way for the photographic community to deal with it.

I don’t think the argumentative tone of the petition in general, and the demand that Sony publicly call their baby ugly in particular, is useful. For reasons that I’ll get into, it’s quite possible that there is no firmware fix to be had, and Sony’s announcing to the world that they are shipping a defective camera just isn’t in the cards, especially since most users of the camera probably won’t detect that there’s anything wrong, and will love the pictures they’re getting.

Why don’t I think it can surely be fixed in firmware? First, there’s Mike Collette’s work, which indicates that the biggest part of the forcing function comes from the stopping of the first curtain, which occurs 1/160 second into the exposure. There’s another portion that comes from the tripping of the first curtain. We’ll have both of those no matter what’s done in firmware. There is a vibration that occurs when the motor that’s winding the shutter reaches its end-of-travel. Firmware deltas could separate that in time from the opening of the shutter, but it doesn’t look like the biggest source of vibration to me. It’s certainly not the only source of vibration. Mike’s analysis, together with evolution of my own thinking, has caused my earlier belief in a complete firmware solution to evaporate.

I’ve been posting about the design of camera support systems in general and ones for the 7R in particular. I’ve made two blog posts on the subject already (here and here), and I’ll make a third today. Here’s a quote from the upcoming post that bears on the issue:

Now that I consider the physics involved, I’m beginning to appreciate what the Sony engineers probably meant when they said one of the toughest challenges in the design of the a7 and a7R was getting the shutter to work in such a small space. Here’s what I think they were talking about. You don’t want to have either shutter curtain’s pre-firing position to be right at the image edge, because that means that the curtain has no time to get up to speed before it starts exposing the sensor, and the first part of the exposed image will get too much light. So you want the curtain to start moving, let it get up to speed, and then have it start to expose the image. But that takes room. If you don’t have the room, you have to accelerate the shutter more, and that causes higher frequencies in the forcing function.

Similarly, when the shutter curtain reaches its end of travel, you can’t stop it right at the edge of the image; you need to stop it after it’s left the image area. But if you don’t have much room, you need to stop it fast. Thus, in a small camera, you have to decelerate the curtain at a higher rate, and that causes higher frequencies in the forcing function.

One of the things – and perhaps the most important thing – a petition could do is to open up a dialog between Sony and photographers that would result in Sony’s making better cameras in the future. To effect that end, the petition ought to make the Sony folks want to work with the photographers.

[Addition: I see that Mr Chambers has modified his petition so that it is less pointed. I think that’s a good idea.]

{Further addendum. Mr Chambers has decided to close the petition to further signatures. It looks to me like it’s now simply a shot across the bow of the Sony armada, intended to get its attention, and not necessarily to push for a public apology. If that’s the intent, I appreciate the effort.]