What is IS???

[Big_B]

Ok I know this is a really stupid question. But what is IS? :oops: :oops:

S

[Scottes]

Image Stabilization

It involves a element inside the lens which moves to compensate for lens motion. (I'm not really sure how it detects lens motion, though.) But this elment will move around trying to keep the light aimed accurately, thus reducing blur from lens shake.

It can increase stability and thus sharpness up to 2 stops. So on a non-IS lens handheld the general rule of thumb is to have your shutter speed 1/<lens length>, so a 400mm lens should be at 1/400. With IS, though, you can go 2 stops slower, so 1/100 is generally OK.

That's is all relative of course, and general rule of thumb. But an IS lens will produce a more stable image.

Nikon calls this VR - Vibration Reductions, and Sigma calls is OS - Optical Stabilization. At least I think those are the terms, but the acronyms are right.

[Big_B]

You are a gent!

[CyberDyneSystems]

Essentially.. a small group of lens elements is stabilized by a gyroscope (two in fact)


:)

[Scottes]

Essentially.. a small group of lens elements is stabilized by a gyroscope (two in fact)

I figured that they had to use a couple gyroscopes, but I had never heard this so I wasn't going to venture...

[robertwgross]

Essentially.. a small group of lens elements is stabilized by a gyroscope (two in fact)


I know that much is true, but I have no details. Does anybody know a source for more technical detail?

I have my first IS lens coming by UPS right now, so I want to read up on the gizmos inside. When I understand the black magic better, sometimes I can make better use of it.

---Bob Gross---

[Jesper]

Canon's EF Lenses Home (http://www.usa.canon.com/eflenses/) has a description of IS (click on "Canon Technology" on the left side).

For Bob: that description isn't really very technical - I can remember seeing a post sometime, somewhere with a link to Canon's patent on IS, which was really technical.

[dn7elson]

But what is IS?

You can see an animated demonstration at the Canon Museum website:

http://www.canon.com/camera-museum/tech/room/b_tebur.html

[Roger_Cavanagh]

Here's (http://www.rogercavanagh.com/helpinfo/34_is.htm) some stuff.

Regards,

[robertwgross]

These are all pleasant descriptions, but I was looking for something a lot deeper. Thanks.

---Bob Gross---

[Jesper]

These are all pleasant descriptions, but I was looking for something a lot deeper. Thanks.

---Bob Gross---

Try searching for the patent at the website of the United States Patent and Trademark Office (http://patft.uspto.gov). If you search for Canon and "Image Stabilizer", you'll get a whole list of documents, for example patent # 6,735,383 (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1=6,735,383.WKU.&OS=PN/6,735,383&RS=PN/6,735,383). I haven't looked at those documents in detail, but probably there's a more in-depth description of how IS works in there.

[DocFrankenstein]

But what is IS?

You can see an animated demonstration at the Canon Museum website:

http://www.canon.com/camera-museum/tech/room/b_tebur.html
I've read somewhere that the IS system was composed of 2 independent prisms with some kind of fluid between them.

Your link gives a "lens" that moves up and down :?