Tamron AF 18-270mm F/3,5 -6,3 Di II VC LD Aspherical [IF]

[bakubo]

Barry, when you are shooting with a Canon 1D MkIII - an extremely fast-reacting camera - then the 0.5 to 1 seconds which a Canon IS lens requires before stabilisation operates can be critical.

I have noticed this with my Tamron 18-270mm VC, but it only happens when you wake up the VC system after it has gone to sleep, not for every photo you take. To avoid this issue what I do is press the rear AF-ON button with my thumb (or half-press the shutter release) as I am raising the camera to my eye so that by the time I am looking through the vf the camera and lens VC are awake.

IMO, the ideal IS system would have both IBIS and ILIS. A company like Canon or Nikon have quite a few ILIS lenses, but most of their lenses don't have it -- not to mention all the Tamron, Sigma, Tokina, etc. lenses. If they added IBIS then all those unstabilized lenses would instantly be stabilized and they would still have their ILIS lenses. Probably will never happen though. Partly for business reasons and partly for ego reasons. Sony and Pentax do have IBIS, but partly for business reasons and partly for ego reasons they refuse to use ILIS for lenses where it would be good and better than depending on ILIS. Recently Sigma does have a few A-mount OS lenses, but not many. Considering all the A-mount lenses from Sony and others, such as the Tamron 18-270mm, though that don't have IBIS Sigma is the odd man out. Does Pentax even get OS in Sigma lenses?

I guess Canon or Nikon could do it very quickly if they wanted since it would just involve new bodies which they come out with from time to time anyway. Sony and Pentax would find it much more expensive and take much, much longer since it would mean coming out with new lenses -- along with Tamron, Sigma, Tokina, and other 3rd party makers.

[alphaomega]

Re bakubo comment

I guess Canon or Nikon could do it very quickly if they wanted since it would just involve new bodies which they come out with from time to time anyway. Sony and Pentax would find it much more expensive and take much, much longer since it would mean coming out with new lenses -- along with Tamron, Sigma, Tokina, and other 3rd party makers.

I would say that Sony already have ILIS in their E-mount 18-55 and 18-200 lenses so it is not as if the concept is new to them. All they had to do would be to add ILIS to their new telephoto lenses and tele zooms going beyond 200mm at the long end. Since they have introduced the NEX concept and provided an adapter that can auto zoom A mount lenses it would be a good idea anyway to add ILIS to at least lenses with a tele reach. Particularly since the E mount lens release stretches out quite a bit before a reasonable assembly is available. Could do with a mini sort of 50-200mm F4-5.6 ILIS tele and a 12-20mm W/A zoom. The 18-200 is too big and heavy for light use with the NEX. Kind of defeats the purpose of light weight and portability.

[agorabasta]

An ideal case would be to have IBIS/ILIS working together. IBIS is always better for the slow shake/drift, and the ILIS is inherently better for fast shake compensation and just horrible for drift. Setting the crossover frequency for those two systems at some standard value will enable simultaneous operation of both for all lenses observing such a standard.

And I don't think that Canon/Nikon can do that - too many design changes to the bodies, including sensors operation, too much of financial burden to take while their current systems sell well enough. Sony, Pentax and possibly Olympus might try. In fact, the Olympus could benefit most from that...
Or that could be Sony with the Nex...

[David Kilpatrick]

That's the exact reverse of what Sony's engineers told me. They said the SSS had been improved for low frequency slow drift over Minolta's AS, which was at its best for frequencies around 60-100Hz in terms of changing direction. They also said that SSS was better for very small fine frequency movements, in-lens better for larger slower movements.

But KM's demo module used a fairly slow cycle of vibration, I don't know what it was but it looked like maybe 10Hz.

David

[agorabasta]

David, that Sony guy was telling a somewhat different thing - moving the active element at high velocities/accelerations really is easier with IBIS, but for the ILIS you may need to rather keep the active elements in the lens almost non-moving while the rest of the lens bulk shakes around, so inertia is your friend in case of ILIS.
Still the IBIS may be made very precise for slow shake/drift compensation, and the only 'problem' it has there is that you have to use good motion sensors (laser gyros / accelerometers) adding to the costs. But that's no fundamental problem

And surely KM was very good exactly at drift compensation. I still think the best IBIS to compensate drift I ever had in my hands was that in the KM Z3 superzoom.

[Greg Beetham]

Doesn't ILS suffer image degradation to an extent from scruffing around with the lens element alignment, also over time the system itself has some progressive degradation...only from what I read, they may have improved it of course.
Greg

[bakubo]

Doesn't ILS suffer image degradation to an extent from scruffing around with the lens element alignment, also over time the system itself has some progressive degradation...only from what I read, they may have improved it of course.

I don't know, but sounds reasonable. If so then it is another reason why using IBIS for lenses where it makes the most sense and using ILIS for lenses where it makes the most sense would be the best. The stabilized vf is nice for longer lenses, but who needs it for short lenses? That was a rhetorical question, but I just remembered some years back when KM came out with AS in the 7D and then the Sony A100 with SSS there used to be lots of threads about IBIS vs. ILIS. There was a guy on the Canon forum who claimed that he didn't want to use a camera that didn't have a stabilized vf. I acknowledged that for longer focal lengths it was nice, but for shorter focal lengths I found it unnecessary. He claimed that he needed it even for 17mm when using his Canon 17-85mm IS. I suggested that if he couldn't hold his camera steady enough to even compose without a stabilized vf at 17mm then IS probably wouldn't save him. I wonder if it means he never used any of the many Canon non-IS lenses?