(commentary)
Recently there has been some discussion about the vulnerability of VR and IS that was triggered by something my friend Roger Cicala of Lens Rentals said during a recent interview.
So let’s start there.
Well, let’s actually start with the paraphrase that’s been traveling around the Internet since the interview: "You should always turn off image stabilization on your lens before you travel so as to lock floating lens elements in place and minimize the chances of them being jostled and damaged en-route.” This quote first appeared in a PDN Online article, and was attributed to Lens Rentals.
Curious about that “statement of fact", I contacted Roger directly. Yes, it turns out that Lens Rentals now ships everything with IS/VR/VC turned off. But let me have Roger do the talking:
“In our experience lenses with VR / IS / VC have higher repair rates overall than those that don't have it. Most Canon IS units, for example, have the element floating or sliding in a cage made of 3 or 4 thin plastic bars, and we have seen these bars cracked or broken in some IS failures (other failures are purely electrical).” says Roger.
"Our conclusion is that it's possible the crack could occur from the element rattling around in unlocked position. We’re not certain of this, but it’s certainly possible. (When the lens is active the magnets keep the lens element from hitting the plastic cage, but with it off they certainly can bang on it; we have seen this in some opened lenses). Our conclusion was that it's better safe than sorry, lock the VR/IS just in case.”
Roger continues: "We have seen a slight reduction in Canon IS failures since we started making it a requirement that all IS units are always locked. But it's not enough to approach statistically significant.”
Some lenses physically lock the VR/IS when turned off with the lens still mounted to an active camera before removing the lens. Indeed, Nikon even warns about turning off the camera with VR still active, which made me wonder if Nikon locks VR elements (more on that in a moment).
On the Canon side, the 100mm f/2.8 IS Macro, 70-200mm f/2.8 IS II, and the new 100-400mm seem to lock the IS when you turn it off before removing the lens. But on the Nikon side, it appears that it doesn’t make a difference. A good rule of thumb is that if you gently shake a removed lens and hear a rattle, then the VR element might be not locked into position. I had Roger do some tests on this with his big stock of Nikkors, and he reported this:
“Nikon’s VR unit rattles very softly, nothing like the Canon, but it doesn’t matter whether you power down VR or not before removing the lens from the camera: the Nikon VR rattle does not change.”
Moreover, non-VR lenses don’t have this soft rattle, so it must be that the rattle Roger is hearing is due to VR.
But then there’s this from Roger: “Our data don’t show any reduction in Nikon VR repairs after we started turning off VR before shipping.” He cautions that the number of Nikkors he rents out is far lower than Canon, so perhaps the sample size is not large enough to show a difference yet.
Thus, the thing that PDN “learned” from Lens Rentals isn’t actually quite a completely accurate statement. It’s certainly not a harmful statement, but I’ve gotten enough emails from people with a dash of fear in them about that article that I wanted to follow up on this and get closer to the truth.
Meanwhile, the dialog between Roger and I moved over to sensor-based IS. Olympus clearly warns users against cleaning the sensor manually as it might damage the 5-axis IS system. Roger hasn’t seen an example of cleaning causing a problem—they clean sensors on all their rental cameras fairly regularly—but he did note that the original Sony A7 designs (on the pre Mark II models) had a very high failure rate for them. The IS plate would jump out of its cage. Since Sony changed the design for the Mark II models, Roger says that they haven’t seen a failure, despite cleaning the sensors on those cameras regularly.
So what do we know at the moment?
- There’s no statistically significant evidence that turning off the IS/VR/VC (and potentially locking the lens element) on lenses that otherwise let the element float damages the system in transit. But there is enough anecdotal evidence on the Canon lenses to suggest that this might have reduced the failure rates slightly. In other words, it isn’t a panic situation here, but if you want to play it safe, turn off the stabilization system before powering down the camera and taking off the lens for transport.
- There’s no evidence at all so far that cleaning sensors with stabilization built in damages them, though there is Olympus’ warning to consider. Personally, I’d be careful in cleaning such sensors, and I’d be gentle in doing so. Force is not your friend, and force isn’t something you should be using to clean a sensor. Indeed, if you’re using anything approaching brute force, you’re probably using the wrong cleaning method.
There you have it. To summarize my VR recommendations for Nikon shooters:
- If you want to use Lens Rentals’ conservatism, always turn the VR switch to off before removing a VR lens from a Nikon DSLR
- Always turn the camera off before removing a Nikon VR lens, regardless of VR switch position
- Only turn VR On when you absolutely need it (see my All About VR article), and the first two recommendations become moot most of the time ;~)
