Canon on Canon IS

[John Chardine]

I was looking at a tech article on the 70-200 f2.8 II on Canon's camera museum website here:

http://www.canon.com/camera-museum/tech/report/2010/08/

and noticed these two comments regarding IS:

*1 Image stabilization generally reaches its effective limit at a shutter speed of about 1/[focal length] seconds.
*2 Image stabilization is most effective at shutter speeds between 1/25 of a second and 1 second.

I found the first comment interesting because it reveals Canon's technical thinking on IS, which is significant because they invented the technology or at least brought it to market first. The issue of IS or no IS has come up several times at BPN with the conclusion that if it doesn't provide benefit but costs nothing, leave it on anyway. Costs could be lower battery life, wear and tear on the IS/VR system, and Roger has mentioned an issue with the 300/4 at high SS, so costs are potentially low. But should we really be heeding Canon and turning IS off at 1/300s for a 300mm lens?

[Roger Clark]

Hi John,

A strange statement (1/FL) as that guide was developed in film days. Many of today's sensors have about double the resolution of fine-grained film. So the metric should be more like:
(8/pixel size in microns) /FL.
A 7D needs finer stabilization than a 1DX, for example. Then on the other end, that stabilization is effective at 1 second exposure times is a joke. The system drifts, and anything longer than about 1/10 second will show blur on many frames. Sounds like marketing didn't try out the system, or the person who wrote that is still using film, and still didn't try long exposures of 1 second. Maybe they should turn on "live view" and check effectiveness and update their information.
(rant over, need coffee.....):w3

Roger

[arash_hazeghi]

Hi John,
I totally agree with Roger, 1/focal length is from the film era...and 1 sec is a big joke indeed...Not sure who puts this stuff up on Canon site.
One major problem with all the Japanese companies is that technical stuff is ALL in Japan and done by people who don't speak English, most of the people they hire here in the US are marketing/consumer support and they don't really understand the technical parts of things. If your read the Canon manuals you can find some errors too.

Another joke is the 4MB compressed and heavy NR 1DX JPEG "Samples" they recently put online. They look like garbage at a time Nikon is posting on 35MB D800 samples with mind bugling detail...go figure.