# Why Dont more lenses have IS?



## nightphoto (Feb 6, 2012)

I'm newish to high end photography, but one thing has struck me. there dont appear to be a lot of EF lenses with IS.. is there a reason for this? is it not as required on short focal lengths?


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## Dianoda (Feb 6, 2012)

nightphoto said:


> I'm newish to high end photography, but one thing has struck me. there dont appear to be a lot of EF lenses with IS.. is there a reason for this? is it not as required on short focal lengths?



Yep, implementing IS adds marginally to weight and cost, isn't as necessary for short focal length/large aperture lenses, and provides little to no IQ benefit at high shutter speeds. The combination of the standard convention of a shutter speed of 1/focal length to avoid image shake from camera movement and the large apertures typically found on the short L primes tends to limit the practical need for image stabilization.

I mean, how dark does it need to be for a shutter speed of 1/50 @ f/1.4 not to be enough? Answer: if it's that dark, use a tripod if subject movement is not an issue, and if subject movement is an issue, then no amount of IS will save you.

Seems to me like Canon's general response to IS in short focal length lenses has been "why bother?" Of course, 2 rumored EF primes with IS could mean that Canon might be changing their stance...


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## JR (Feb 6, 2012)

Not really. At short focal lenght, you can get away with a lower shutter speed. IS is certainly not required at the 24mm and 28mm for *still photography  * (referring to the two new picture on the site here). IS *will  * be usefull for video however.

Again for still, below 100mm IS has a lesser value ...


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## Halfrack (Feb 6, 2012)

It's cheaper to buy a body that handles higher ISO better than it is to put IS in many lenses. Then there are times when IS isn't used at all - the rule I keep hearing is anything faster than 1/320 is going to render IS useless.


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## Cannon Man (Feb 6, 2012)

I don't know if I'm right on this one but if adding IS reduces image quality at all by making the construction more complicated i would not want it in lenses under 200mm!!


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## Dianoda (Feb 6, 2012)

Good call with the note about IS and video, IS on the new 24mm and 28mm primes makes a lot more sense now...


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## se_photo (Feb 6, 2012)

I've had erratic Scheimpflug-style focus issues with IS and VR lenses and am glad it's not a ubiquitous feature. I trust lens elements that are aligned and locked into place. That said, my new 70-200 2.8 ISII has proven to be a great lens so far. (fingers crossed). I'm prepared to dump it for a 135 if it gets nutty though...

Consider using a monopod and all your lenses get a virtual IS/ VR makeover for $100!


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## briansquibb (Feb 6, 2012)

se_photo said:


> I've had erratic Scheimpflug-style focus issues with IS and VR lenses and am glad it's not a ubiquitous feature. I trust lens elements that are aligned and locked into place. That said, my new 70-200 2.8 ISII has proven to be a great lens so far. (fingers crossed). I'm prepared to dump it for a 135 if it gets nutty though...
> 
> Consider using a monopod and all your lenses get a virtual IS/ VR makeover for $100!



Tripod and gimbal is another way to go


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## Flake (Feb 6, 2012)

Age is one good reason! Not all of Canons lenses are recent, and some of them date back to the time when IS hadn't been invented. Excluding the 100mm macro IS doesn't make an appearance on prime lenses until the 200mm f/2 (bit pricey that). The attraction of prime lenses is the wide aperture and light weight compact size, adding IS would more than double that in many cases.

In terms of zooms though you can buy an IS lens from 24mm all the way through to 800mm. Nearly every zoom lens from 70mm upwards is available with IS, some of course are available without it in case you don't want it or can't afford it. It's not an insignificant price though, it doubles the cost of a 70 - 200mm f4 L.

Below 70mm though there are much fewer lenses, there is a school of thought that image quality is compromised, and weight and size are also badly affected.


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## Mt Spokane Photography (Feb 6, 2012)

They are slowly appearing at wider and wider focal lengths. There is demand for them, whether they are needed or not. They affect the optics in a large way, and raise the price by a large amount as well.

There is little doubt that inexperienced photographers benefit from IS, they do not understand how to determine shutter speeds. I'm not referring to those who regularly post here, they understand for the most part, but those who just drop by their local best buy store to upgrade their powershot, expect IS and 10:1 zoom on their DSLR, and ... money talks!


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## archangelrichard (Feb 6, 2012)

Part of this is in how IS works - just as an iphone or ipod senses orientation, the camera senses movement and reacts by moving the rear elements just a very slight bit -- this may result in a blurrier photo if that movement was intentional (i.e. panning) and your lens is now fighting you

In a wide lens the movement is so small as to be almost impossible to control so IS would be a problem; plus it makes for a wider lens and mounting that on a camera may present a problem (still giving you access to DOF preview, etc.)

As has been stated above, it is less necessary with wide lenses, largely because any movement is less of a movement than with a telephoto. From http://www.paragon-press.com/lens/lenchart.htm " Very simply, it is the distance from the lens to the film, when focused on a subject at infinity. In other words, focal length equals image distance for a far subject. To focus on something closer than infinity, the lens is moved farther away from the film. This is why most lenses get longer when you turn the focusing ring." So, consider this; a 28mm lens means the camera and lens swings an arc of 28mm from the focal plane to the front lens while a 200mm lens swings an arc of 200mm (vast oversimplification for illustrative purposes) so the 200mm lens makes many times the movement of the 28mm and needs many times the IS to counter that movement


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## Caps18 (Feb 6, 2012)

I find that fast shutter speeds are more important than IS. And that is impacted by how much light you can get to the sensor.


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## elflord (Feb 7, 2012)

nightphoto said:


> I'm newish to high end photography, but one thing has struck me. there dont appear to be a lot of EF lenses with IS.. is there a reason for this? is it not as required on short focal lengths?



It's not as necessary on short focal lengths. The rule of thumb is that you need a shutter speed of 1/f or faster to avoid camera shake affecting the picture. So that's 1/24s with a 24mm focal length, or 1/135s with a 135mm focal length. Also, short to mid range lenses, especially primes, are more likely to have a maximum aperture that permits a fast shutter speed (e.g. f/2.8 or faster) whereas this most teles, especially zooms are slower (e.g. f/f5.6)


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## Mt Spokane Photography (Feb 7, 2012)

elflord said:


> nightphoto said:
> 
> 
> > I'm newish to high end photography, but one thing has struck me. there dont appear to be a lot of EF lenses with IS.. is there a reason for this? is it not as required on short focal lengths?
> ...



I usually Increase those numbers by a 1.6 factor for a crop camera. Perhaps that is why the 15-85mm and the 17-55mm lenses have IS.

http://en.wikipedia.org/wiki/Crop_factor

"The extra amount of enlargement required with smaller-format cameras increases the blur due to defocus, and also increases the blur due to camera motion (shake). As a result, the focal length that can be reliably hand-held at a given shutter speed for a sharp image is reduced by the crop factor. The old rule of thumb that shutter speed should be at least equal to focal length for hand-holding will work equivalently if the actual focal length is multiplied by the FLM first before applying the rule."


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## 7enderbender (Feb 7, 2012)

nightphoto said:


> I'm newish to high end photography, but one thing has struck me. there dont appear to be a lot of EF lenses with IS.. is there a reason for this? is it not as required on short focal lengths?



I personally hope it stays like that. I see very little value in IS except maybe for a few specialty applications or very long focal lengths. It adds cost, weight and is another thing that will break or get the lens out of whack at some point. It does work to some degree. I have it on my 24-105 but again there isn't much that I would use it for and it's actually one of the reasons I'm still thinking about trading it for the original 24-70 while it's still around.


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## AJ (Feb 7, 2012)

[quote author=somesone said]
use a tripod
[/quote]

Tell that to the wedding tog, working quickly, as the procession comes up the isle. The photojournalist trying to get the shot of someone in the news. Travel photographer going light. Nightclub shooter in the moshpit.

IS is awesome and tripods are a necessary evil. I love the stabilization on my 17-55/2.8. I've gotten shots I never would have without IS. Never ever have I said: gee I wish this lens didn't have IS.

Canon, put IS on more lenses please!


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## Rocky (Feb 7, 2012)

The "1/F rule" is from the old old film days. During that time the combined film and lens resolution is nowhere close to 10 Meg (digital FF equilvalent resolution). Nowadays with better lenses and higher sensor resolution, I would at least use 1/2F for FF and 1/3F for APS-C. That mean even with F=24mm, the safe hand held speed will be 1/75 sec. Therefore IS will be good for any focal length as long as it does not make the image quality worse and as long as the additional price is reasonable.
There are a lot of situation that tripod or even monpod is not an option, eg: museum, shows, concert, weddig, friends and family gethering, etc.


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