Should be buying my new lens tonight for my Canon EOS 350D, its a canon EF-S 55-250 USM IS and should give me everything i want.. more length of course, im forever on the 55 stop on the kit lens and needing more so this should do the job.

Pictures soon no doubt.

Well its here and awesome!


The arsenal, new lens and hood on the left, 350D and kit lens on the right.

Now a quick set of shots:


18


55


55 IS


250 IS

Unfortunately lost my usual hosting so cant upload the full size images stuck with photobucket.

That last shot is pretty impressive. How much did the lens cost and from where?

I presume IS = Image Stabilisation?

yeah thats right for the IS, pretty impressive bit of kit.

£220 from castle cameras in bmouth, hood was extra though not that i need it really.

How does IS actually work, is the lens floating/suspended or something?

I guess google is my friend heh.

From what I understand you either have image stabilisation built into the camera body or the lens; its either the sensor that is moved very small amounts or the lens that is suspended using electromagnets that counteracts the movement.

In SLRs its almost inevitably done through moving lens elements inside the lens, simply because moving the sensor wont show through the eyepiece.

On my old Panasonic fz30 its done by moving the sensor because you see the sensor image. Technically this would be a cheaper option overall for SLRs as it wouldnt need it built into every separate lens.

Another option is to have a slightly larger sensor and match the image movement electronically, this tends to be used in video cameras.

i have no idea how it works, its built into the lenses on this nothing in the camera at all, can hear it clicking and whirring when its on though, uses USM (ultra sonic motors) for focus as well, very cool

so when you say the lens elements move do they try to detect and counter movement by the camera (shaking hands or whatever)?

My Pentax has gyro sensor whatsits built in to the camera body which adjust the position of the sensor to compensate for shake. The advantage is that it works for any lens and can also compensate for rotation as well as up/down/left/right.

I got the impression in the past that the Canon and Nikon systems work off the AF sensors, allowing the system to work with older bodies, but I dont know if thats accurate. However it decides what to do, those systems have a movable lens element which does the actual compensation.

However it works, IS/VR/SR/OS is the best thing since sliced bread. Having had it on my K10D for a couple of years theres no way Id be without it.

It analyses the movement and tries to counteract it, effectively its worth 2 to 4 stops.

http://cpn.canon-europe.com/content/infobank/lenses/image_stabilisation.do

Quote from: Binary Shadowso when you say the lens elements move do they try to detect and counter movement by the camera (shaking hands or whatever)?

Theres a pair of angular velocity sensors mounted on the lens that detect the shake on the horizontal and vertical axis and adjust the lens elements very slightly to compensate.

cool..

having looked through it at 250mm with and without IS im very glad i shelled out the extra £90 for IS, its impossible to not get shake at that length without IS

Ive got a 100-300mm lens that I occasionally use hand held, entirely depends on available light though.

Quote from: SeriousIve got a 100-300mm lens that I occasionally use hand held, entirely depends on available light though.

I have my 70-300 sigma without IS and thats the one I mentioned about almost always being soft. Its tempting but not quite a priority at the mo!