Neuroanatomist have you got your 100-400? was I right regarding the IS system? the 300f4 IS L has the same one so it's not a very good one but it is there.the best thing is never to try the IS in the 70-300mm IS and you will not be dissapointed.otherwise.....
I rented the 100-400 last week and I was amazed by the IS. I've even made a sharp picture handheld at 1/6th, but my keeperrate was 1 out of 100 I guess[:P] 1/30th of a second did very well for me. At 400mm of course, forgot to mention that. But those are all subjective to a lot of things. When I had the 1/6th shot is my subject was like 6,5-7m away and the short distance makes the IS function a lot better! Since the weather was amazingly foggy I didn't really made far away shots (I did, but they where rubbish in the nicest way), so I can't tell how good the IS was on further focus distances.
Anyway I was very pleased with the IS in the 100-400. Theoretically 2-stops perhaps, but I had a lot more. I'm also curious how this "2-stops" definition is made. Is there a particular standard? Focus distance (or subject-distance) plays a big role in my believe, so there should be some sort of test to determine the IS functionality. Or is it just a lot of shooting and taking averages?
Originally Posted by adrian mandea
Yes, I received my EF 100-400mm f/4.5-5.6<span style="color: red;"]L IS USM lens earlier this week. I haven't had a chance to get outdoors with it yet (has been raining all week), but I have tested it indoors.
To answer your question, no, I don't think you were right - the IS on the 100-400mm performs exactly as I would expect. At 400mm, the 1.6x crop makes the angle of view equivalent to 640mm. The 1/focal length guideline suggests I should be able to handhold that at 1/640 s - and keep in mind, that's a guideline, what it really means is that at a shutter speed of 1/focal length, an 'average' person (whatever that means) should get about a 50% keeper rate. With IS off, that's just about right - slower than 1/640 and I start to get many shake-blurred shots. IS for this lens is rated at 2 stops. So, that means zoomed to 400mm I should get a 50% keeper rate at 1/160 s shutter speed. In fact, I get a decent hit rate even at 1/100 or 1/80 s (still over 50%).
I'd be disappointed in the IQ of the 70-300mm lens,in the rotating front element and the lack of full time manual focusing. Those are the reasons I didn't buy that lens. But I'm still not sure why you feel disappointed in the IS on the 100-400mm. The 70-300mm at its longest focal length, with it's 3-stop IS, should allow you to handhold (at that 50% keeper rate) down to about 1/60 s - that's one-and-a-third stops faster than the 1/160 for the 100-400 at it's full extension. I suspect it comes down to expectations. My EF 100mm f/2.8L Macro IS USM has 4-stop hybrid IS - I can get sharp handheld shots at 1/8 s. I've gotten sharp images handheld with my EF-S 17-55mm f/2.8 IS USM (3-stop IS) at 1/2 s shutter speed, due to the combination of short focal length and IS - that's a speed you'd normally need a tripod to achieve. I certainly don't expect that from the 100-400mm lens - it performs as it should in my hands.
enjoy it,and let us see some images when the weather will be better
adrian
Nearly 70 °F outside now! []
Here's a 100% crop ofa shot from this morning:
EOS 7D, EF 100-400mm f/4.5-5.6<span style="color: red;"]L IS USM @ 400mm, 1/160 s, f/5.6, ISO 200
Seems pretty sharp to me, even with pixel peeping. [] At 400mm (640mm FF angle of view), this shot at 1/160 s should be pretty blurry due to camera shake. Admittedly, I had a cooperative and relatively still bird or else 1/160 s would likely not have been enough to freeze the subject motion. But it seems the IS is doing a pretty good job!
The other thing to keep in mind is that IS takes a while to stabilize the image (at least half a second, sometimes up to a full second). So, if you just press the shutter button halfway (or the AF-ON button in my case), wait for focus confirmation, then shoot, you won't be getting a stabilized image because AF occurs much faster than the time it takes the IS to fully kick in.
I've noticed the IS delay ,it is slow to activate.Today I was doing some shots in the house with the tamron extender attached and I've noticed that sometimes when I prees the shutter button to take the picture the image jumps (right in that moment)and ruins the picture,but I think this is due to the extender not the lens.
again, enjoy your tele and keep shoting
adrian
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