Why IS is not available on many primes???

[bmpress]

Hi Bob,

Since I have the 17-55 f2.8, and the 100-400 f4L, I thought about filling in with the 85mm f1.8 prime which you gave a fabulous review. But then I realized it did not have IS and I am wondering why Canon does not offer it?

Since I feel a need for IS, what would you suggest for the missing hole in my equipment? I would be using it as a walk-around tele on 50-d in evening light.

Thanks,

Barry P

[KeithB]

We are not Canon, but I guess they don't want to go through the hassle of a re-design.  You can get the new 100mm macro with IS, and I imagine as they re-do all the lenses they will add IS, but it certainly does not seem to be a priority.  And at f/1.8 do you really need IS? 8^)

[KeithB]

Just did a quick survey of non-zoom lenses on the Canon site.

9 Wide-Angle Lenses, 0 with IS
6  Normal - short telephoto lenses 0 with IS (the 85mm is in this group)
5 Telephoto lenses, 2 with IS
7 Super Telephoto lenses, 6 with IS
5 macro lenses, 1 with IS (the 100 mm, obviously)

I think you can see the pattern here, the 100mm macro really stands out.  Does this signal a new direction for Canon?
Note, too that most wide-angle zooms don't come with IS, either.

[klindup]

Why would anyone want IS on a wide angle lens, or anyting other than a telephoto.  For many years until I brouht a DSLR I used a variety of lenses up to a 400mm and never thought about IS.  Never had any problems with getting sharp images and never went above ISO400 film.  Don't get me wrong IS is nice to have but is it really worth the extra cost?

[Bob Atkins]

It would be nice to have but there are some technical issues. Generally the optical design on the lens has to be changed to allow for a movable element group, plus the mechanical design has to be changes to make room for the IS mechanical components. In a relatively small prime lens with only a few elements, this could result in increased size and/or increased cost and or lowered optical performance.

The 100 macro IS is a separate case since it's a novel hybrid IS system designed for macro use. I doubt it signals a general move to IS primes.

I'd like IS in my 85/1.8, though I wouldn't like a $200 price hike. Of course if the price difference was $50, that would be a different matter. Canon can certainly add some form of IS fairly cheaply since the 18-55 IS sells for around $150.

I wouldn't be surprised to see a few IS primes appear, but I'd expect (and hope) to see it in longer lenses like the 400/5.6L, 200/2.8L and 135/2.0L first since it would be more useful on those lenses (and the 400/5.6L really needs it).

It is less useful on superwides and may also be less effective. There is some image drift at long exposures, so if you're shooting at 1/15s with a 14/2.8L and you add 4 stops of IS, I'm not sure how well the image could be held stable for 1 second without some drift.

[whizkid]

Seems to me I read an article about two years ago that stated image stabilization effectiveness bottomed out  by 1/4 second and added  no benefit beyond. Sure would be nice to know if such a wall exists.

[Bob Atkins]

Yes, there is certainly a lower limit on IS, but I don't know exactly what it is. If you put an IS lens on a tripod you can see the image slowly drift and I assume you also get some slow drift when handheld. IS is very effective at compensating for motion but there is certainly a shutter speed longer than which it won't work as well. Whether it's 1/4s, 1/2s or 1s I don't know, but even at 1/4s it would still be useful with even the widest lenses and very useful with medium focal length primes.

I'd think that a fast 35 or 50mm with IS would be great for low light indoor work.

[eriq samson]

Consider the concept - on a long lens the smallest movement to set the lens off may be 1/100th of a Millimeter; (the arc of the swing) but on a short lens that may be 10,000th of a millimeter - how do you even machine anything that small? WHY would you?

Yes Canon makes IS for the normal range zooms - they likely don't do anything but at the extreme zoom and even then not much - but it is a marketing ploy more than anything

IS on short lenses is like labelling a door "VIP entrance" and then allowing everyone to come in that door - strokes their ego more than anything else

[whizkid]

I  find "IS" beneficial in every lens I have it in (7 currently) as I'm less able to steady a camera as well as I once could.  I've done enough personal testing of "IS" that even for some wide angle shooting it benefits me. It's also  in in my 3 P&S cameras,  a Canon S90 ( a great model for low light.), a Panasonic TS2 for the harsh and wet and a Panasonic FZ35 supperzoom for outdoor use when I don't want to carry a DSLR. You are dead wrong about it tickling ego because IS is a solid benefit for many of us.