The A7II Teardown: A Look Inside Sony’s New Camera

A while back we did a teardown of the Sony A7r, and were very impressed with its clean modular design. Now that Sony has released the A7 II we thought a similar teardown would be worthwhile. There are certainly going to be some differences. First among them, of course, is that the new camera has 5-axis, in-body image stabilization, which is definitely going to create some differences. There also is a more robust magnesium alloy shell and lens mount, and perhaps (or perhaps not) improved weather resistance.

For anyone who isn’t aware of my cynicism regarding weather sealing, I’ll repeat my quote from The Cynic’s Photography Dictionary:

Weather resistant – A term that consumers falsely define as “weather proof” and camera companies accurately define as “the warranty doesn’t cover water damage.”

Just looking at the cameras from the outside, though, it’s fairly apparent the A7II is larger and heavier than its predecessor.

 

So let’s see what all Sony has crammed into that extra space and how it’s put together.

Some Outside Niceness

A couple of minor, but very nice, points are apparent just looking at the camera. One is what Aaron called “the world’s most impressive battery door.” The spring-latch not only pulls in the posts to remove the door if you put on a grip, it locks them in so they can’t break off (you probably haven’t seen broken battery door posts, but we sure do). It also has a rubber cable opening (in case you want to run the camera from an AC adapter when one becomes available). And finally, it has weather sealing gaskets around the edges, except for one corner between that cable opening and the hinge. By the way, don’t be looking for more rubber gaskets. This was it.

 

One other thing that you probably won’t care about but repair techs will is that the flex connection between the LCD and the camera body is now exposed under the LCD.

 

The time it takes to change out a scratched LCD screen just got reduced 75% — remove two screws, disconnect the flex and the screen is off.

 

This isn’t exactly the outside of the camera, but it’s pretty close. The bottom plate/tripod mount has also been beefed up a bit. When the bottom cover is removed, the plate is obviously thicker and more solidly anchored than the first generation A7 cameras were.

 

The increased stiffness and thickness is more obvious when the plate is removed.

 

While we’re looking at the outside attachments, removing the viewfinder cover shows no weather sealing. It’s possible the plastic fittings are so tight and smooth that they are water resistant, of course, but there are certainly no rubber gaskets like we’re used to seeing.

Let’s Look Inside

We can get our first glimpse at that in-body image stabilization by looking at the area where the tripod mounting plate was removed.  The thick metal sandwich (red bracket outlines the left edge) contains the sensor plate, which is floating on a number of permanent magnets (green lines show the bottom two magnets).

 

Continuing the disassembly, the back comes of with just a few screws.

 

Revealing a thick electrical shield protective plate.

 

Sony states that the buttons on the new camera are sealed, and this is definitely the case for the back push buttons – they are rubber within the back plate, matching up with the pressure sensitive buttons on the board above.

There is no such seal around the mode dial, though. Speaking of the mode dial, it comes off by just disconnecting its flex.

 

With that out of the way, remove a couple of screws and the electrical shield comes right off . . .

 

. . . exposing the SD card board (the small blue circuit board above), which gets removed next.

 

Then we disconnect the WiFi antenna and a couple of flexes.

 

Which lets us remove the circuitry around the battery box,

 

and gives us access to the last screw holding the grip on.

 

The next part to come off is the top. The EVF is a one-piece unit that just slips out after you disconnect its flexes.

With it out of the way, the last screws holding on the top assembly can be reached. Once those are out and the top flexes disconnected, the top assembly comes right off.

Top assemblies are amazingly complex things. We follow the service center’s example and don’t mess with disassembling them. If a top switch breaks, the entire assembly usually gets replaced.

 

I Know, I Know, You Want to See the Lens Mount

There’s been a lot of discussion about the lens mount in previous A7xx cameras being a bit flexible. There was a plastic spacer in the previous mounts and we all wanted to know if changes had been made in the newer models.

 

And they have. The mount is now directly screwed into the magnesium frame of the camera with no plastic spacers, all metal to metal, with just the metal lock spring in between the mount and camera frame.

 

 Now the Good Stuff

Ok, with all the external doodads disconnected, we can get down to the meat of the camera. The heat sink comes off next, exposing the main circuit board below.

 

 

To give you an idea of the electronic complexity of the new camera, there are a total of 16 flexes (not all visible in this image) connecting to the main board now, a marked increase from the earlier A7s. Most of these new flexes are concerned with the IBIS system.

The bottom side of the board is nearly as densely etched as the top, and contains the date-time battery, so changing that is not going to be something you can do at home.

 

There is yet another electrical shield to be removed after the circuit board is out.

 

And now we can finally see the shutter and sensor modules.

 

What you see above is the back plate of the metal sandwich we saw in the first image in the Let’s Look Inside section above. The green circuit board with three large flexes is the back side of the image sensor. Notice the red arrows pointing to three screws. These are the mounting screws for the entire sensor image stabilizing system. The shims that are used to make the sensor parallel to the lens mount are under those. (In this camera the shims were 40, 35, and 30 microns thick respectively, so not a huge amount of correction was required.) To the right of the sensor assembly, you can see the Copal shutter mechanism.

Removing those three screws lets us remove the entire sensor – IBIS assembly.

 

Here’s a close up of the shims, obviously custom made for this camera, not off-the-shelf shims.

 

The sensor – IBIS assembly is a big, heavy piece. You can compare it to the sensor assembly in the A7r in our previous teardown of that camera.

 

While we can’t demonstrate all five axis at which the stabilizer functions, I was a bit surprised at just how much range of movement the sensor has. If you don’t notice the movement in the two images below, look along the right side of the sensor.

 

 

A lot of the magnets in the image stabilization system are permanent, rather than electromagnets. I assume this is to help prolong battery life. Looking from the side you can see the robust rubber-over-metal posts that keep the sensor from moving too far.

 

Finally, with the sensor out we can remove the shutter assembly. Again, like the earlier A7s, there is a lot of modular construction in this camera.

 

 

With all of the modules out, you can see how robust the chassis is. That’s the lens-power flex going from the battery compartment to the electrical pins in the lens mount.

 

This was a much more complex disassembly than the A7r was, largely because of the increased electronics used by the image stabilization system. There were a lot more flex connections and a few more screws, but the overall modularity of the design is still very apparent, especially when we lay out the disassembled parts.

 

Summary

It’s not surprising that the inside of the A7II is more complex than the previous A7 cameras. The in-body image stabilization takes up space and adds circuitry. The camera does largely retain its modular construction, but clearly is more complex to assemble and disassemble.

The A7II is clearly more robust than its predecessors, too. The lens mount seems designed to eliminate any wobbling or looseness that was noticed in previous models and the chassis seems stronger.

We don’t see any real increase in weather sealing, except around the battery door, and even that is incomplete. However, it is certainly possible that Sony has such tight plastic-on-plastic seals that they don’t think rubber gaskets are necessary. Like I said at the beginning, though, I’m pretty cynical about manufacturer’s weather sealing claims.

 

Roger Cicala and Aaron Closz

Lensrentals.com

February 2015