# Why do fast primes not have IS?



## tayassu (Jun 24, 2014)

I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?


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## Maximilian (Jun 24, 2014)

tayassu said:


> I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?


Hi tayassu!

I will try to make an approach, as far as I can handle your question:
IS (Canon) is a moving optical element inside the lens. 
http://en.wikipedia.org/wiki/Image_stabilization
To work properly it has to move fast and accurate. To be fast it has to be of low weight.

Fast apertures need a larger image circle over the whole optics compared to narrow apertures.
Therefore the optical elements of the IS should be larger as well. This leads to higher weight which causes loss of speed and higher energy consumption and also to higher prices because of the more expensive optics.
So with IS Canon always compromises between functionality of the IS and useful max. aperture.

This is my conclusion. Maybe someone else can do better.


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## AcutancePhotography (Jun 24, 2014)

Maximilian said:


> tayassu said:
> 
> 
> > I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?
> ...



Thanks for the clear and unemotional explaination. That is unusual on the Internets Tubes. ;D

Helps people like me get some learnin' ;D


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## David Hull (Jun 24, 2014)

Maximilian said:


> tayassu said:
> 
> 
> > I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?
> ...


I also think that there is a degradation that comes with thee things and the companies that are making fast primes are generally going for the best MTF curve they can get. So putting the IS gizmo in there costs them some performance in that regard. Zooms are always a compromise so for those it doesn't matter as much (and they are already big and heavy).


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## dolina (Jun 24, 2014)

tayassu said:


> I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?


I honestly wouldnt be surprised if the next L primes will have IS. It just that you have to wait for the timing and product cycle to play out for the current generation of primes.


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## ajfotofilmagem (Jun 24, 2014)

Maximilian said:


> tayassu said:
> 
> 
> > I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?
> ...


I agree with your explanation, but I hope that we shall soon have a Canon 50mm F1.8 IS. : Actually, I would like more of a 50mm F1.4 IS, but now that Sigma has a great 50mm, do not think Canon will want a Image Stabilizer version that weighs more than 1 kg and costs $ 1200. :-\


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## IMG_0001 (Jun 24, 2014)

I would add that element alignment is quite critical for fast primes in order to have decent sharpness and uniformity in the image. Possibly critical alignment would be hard to achieve for those fast, thin-DOF lenses.

I'd also second the element weight issue.


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## Larry (Jun 24, 2014)

Maximilian said:


> I will try to make an approach, as far as I can handle your question:
> IS (Canon) is a moving optical element inside the lens.
> http://en.wikipedia.org/wiki/Image_stabilization
> To work properly it has to move fast and accurate. To be fast it has to be of low weight.
> ...



Superteles with IS have large elements.

Weight and energy consumption should therefore be even greater, per your explanation.

Does the larger housing of the superteles provide more space for the mechanism that moves the elements?

Comments?


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## tayassu (Jun 24, 2014)

Maximilian said:


> tayassu said:
> 
> 
> > I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?
> ...



Thanks a lot for the explanation!


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## tayassu (Jun 24, 2014)

dolina said:


> tayassu said:
> 
> 
> > I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?
> ...



I hope so... :


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## CANONisOK (Jun 24, 2014)

I'm sure I'll get throttled for this comment but here it goes: typically, I don't stop down my f/1.2 lenses a whole lot. Sort of negates the point of having them. Therefore I tend to use pretty decently fast shutter speeds relative to the focal length. Others may use theirs differently of course.


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## sdsr (Jun 24, 2014)

I wish Canon would put IBIS in at least some of their dslr bodies (and mirrorless, when/if they ever show up; likewise Sony in its mirrorless cameras), thereby making this a non-issue. I realize there's some controversy whether it's as effective as lens IS, but it works well in Pentax dslrs (Sony too, I understand, though I've only very briefly used one) and Olympus OMDs, and Canon can still keep it in the lenses that have/need it....


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## Dylan777 (Jun 24, 2014)

CANONisOK said:


> I'm sure I'll get throttled for this comment but here it goes: typically, I don't stop down my f/1.2 lenses a whole lot. Sort of negates the point of having them. Therefore I tend to use pretty decently fast shutter speeds relative to the focal length. Others may use theirs differently of course.



+1.......I don't see the point buying f1.2 lens and shoot at f4. On Canon lenses, I like to turn down the dial twice - hit sweet spot everytimes


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## AcutancePhotography (Jun 24, 2014)

sdsr said:


> I wish Canon would put IBIS in at least some of their dslr bodies



So do I. Like everything else in photography IBIS is a compromise. One, that in my opinion, is justified. Canon can still make their telephoto lenses with in lens stabalization as that seems to work better with the longer FLs.

But as you wrote, other manufacturers do IBIS and don't seen to have problems. 

Does video work better with one system? I never shoot video so I have no idea..

With film cameras, the only option was to have the stabalization in the lens. But with digital, the issues of IBIS systems can be mitigated. If either Canon or Nikon were to offer IBIS for their more normal FL lenses and still offer in lens stabalization for those long FL lenses that really need it.

A tog can only dream.


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## AcutancePhotography (Jun 24, 2014)

Dylan777 said:


> +1.......I don't see the point buying f1.2 lens and shoot at f4. On Canon lenses, I like to turn down the dial twice - hit sweet spot everytimes



I see it a different way. I buy a 1.4 lens, not because I want to shoot at 1.4, but because I want sharp images at 2.8 -- stopped down 2 stops. That way on those shots when I need to shoot at 1.4, I can, but for most of the shots I can easily shoot stopped down. 

It all depends on what type of photography each photographer does. Some like to shoot wide open, others like to stop down. I guess that's why they make changable apertures on lenses. ;D


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## mb66energy (Jun 24, 2014)

Larry said:


> Maximilian said:
> 
> 
> > I will try to make an approach, as far as I can handle your question:
> ...



Superteles have large front elements but the IS group is mostly a thin lens element of much smaller diameter nearer to the bajonet than to the front element.

In standard lenses and wide angles you need smaller radii for the lens surfaces so the lenses become thicker and have higher mass - this implies higher forces to reposition them fast enough to counteract camera shake etc.

But your argument - in a tele you have more space - might be an additional reason.

A third one: A 2.8 300mm lens typically costs several thousands of dollars - 500 dollar more for a fast IS isn't prohibitive, it's a 10% increase of the cost or price. For a fictional EF 1.8 50 IS it means a 500% increase of cost or price!


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## CANONisOK (Jun 24, 2014)

Dylan777 said:


> CANONisOK said:
> 
> 
> > I'm sure I'll get throttled for this comment but here it goes: typically, I don't stop down my f/1.2 lenses a whole lot. Sort of negates the point of having them. Therefore I tend to use pretty decently fast shutter speeds relative to the focal length. Others may use theirs differently of course.
> ...


+1. Exactly. If I want something with more DOF, I'll show up with the 24-70ii or the 70-200ii, not a fast prime. There would be more argument for IS in the 24-70ii, as it a slower lens.


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## Mt Spokane Photography (Jun 24, 2014)

tayassu said:


> I'm wondering why fast primes like a 35/1.4 or a 85/1.2 don't come with IS. The fastest lens to feature IS is the 35mm (and the 200mm) f2. Why is that?  People would love a 50mm f1.2 IS : Is there some sort of technical problem? I can't imagine anything else, it would sell well, would set them apart, isn't too expensive... Can someone help me?


 
Those lenses were designed several years ago for full frame cameras. IS was not needed for shorter focal lengths, and did not really start appearing in "L" in lenses until about 1999. It appeared in a consumer zoom in 1995.

Adding IS increased the cost, and like any new feature, it was expensive. The main benefit of IS was in the longer focal lengths where camera shake and vibration was difficult to eliminate blurring. 
With the advent of APS-C Rebel bodies in about 2002, consumers were able to afford Digital DSLR's, and because of the 1.6 crop factor, a 200mm lens was more prone to blurring from shake, and because inexperienced users could just snap off a shot without carefully setting up, the feature became popular and started appearing in APS-C lenses of much wider focal lengths. The feature sold very well, so lenses have been adding the feature where possible. The new 24-70 f/2.8L does not have it. There were prototypes with IS, but apparently, it was not considered good enough or necessary for that lens.
Now, with video in DSLR's becoming popular, IS in wide focal lengths and fast primes has finally found a reason to exist. Handheld video really benefits from IS. That's why we are seeing new prime lenses with IS. They are not f/1.4 or faster, presumably because of the expense and difficulty, but they will come, it can be done, its just a matter of price.


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## CANONisOK (Jun 24, 2014)

AcutancePhotography said:


> Dylan777 said:
> 
> 
> > +1.......I don't see the point buying f1.2 lens and shoot at f4. On Canon lenses, I like to turn down the dial twice - hit sweet spot everytimes
> ...


If you want sharp pictures at 2.8, you need the *24-70ii* or the *70-200ii*. 

http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=397&Camera=453&Sample=0&FLI=0&API=4&LensComp=687&CameraComp=453&SampleComp=0&FLIComp=0&APIComp=0
http://www.the-digital-picture.com/Reviews/ISO-12233-Sample-Crops.aspx?Lens=403&Camera=453&Sample=0&FLI=0&API=5&LensComp=787&CameraComp=0&FLIComp=0&APIComp=0

Just as sharp in center, more corner sharpness, less CA, probably a hair of distortion but that can be fixed in post. And you can change the FL. The right tool for the job.


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## sdsr (Jun 24, 2014)

By the way, there are *some* fast primes with IS - e.g. Sony makes some 1.8 APS-C e-mount primes that have it (35mm & 50mm; maybe others).


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## Maximilian (Jun 25, 2014)

Larry said:


> Maximilian said:
> 
> 
> > I will try to make an approach, as far as I can handle your question:
> ...


Hi Larry! 
Superteles have larger FRONT elements and other lager non moving optical elements in their design. 
The IS is normaly set at a point where the image circle is very small. 
Maybe you are right, that the IS element in the big whites is bigger than inside the 70-200 for example. 
But maybe this is also one important reason for the much higher price.


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## Maximilian (Jun 25, 2014)

David Hull said:


> Maximilian said:
> 
> 
> > http://en.wikipedia.org/wiki/Image_stabilization
> ...


Of course you are right! 
I forgot to mention it directly but it was included in the wikipedia article.
I think this degradation is an issue you can handle by QC and higher quality and prices for the IS element.
See  the 24-70 IS L II or  the 70-200 IS L II. _ edit: Sorry! Made a mistake! _


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## rs (Jun 25, 2014)

Maximilian said:


> See the *24-70 IS L II* or the 70-200 IS L II.


I though we're still on the first version of that f4 lens? :


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## Maximilian (Jun 25, 2014)

rs said:


> Maximilian said:
> 
> 
> > See the *24-70 IS L II* or the 70-200 IS L II.
> ...


touche! :-[
I was dreaming about the EF 24-70mm 2.8L II USM having IS.
Thank you for leting me correct this.


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## Grumbaki (Jun 25, 2014)

sdsr said:


> By the way, there are *some* fast primes with IS - e.g. Sony makes some 1.8 APS-C e-mount primes that have it (35mm & 50mm; maybe others).



1.8 ASP-C is not really fast glass...


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## AvTvM (Jun 25, 2014)

With FF mirrorless cameras taking over some time soon (I hope  ), in-lens IS loses one of it's two advantages over in-body IS: on an EVF, viewfinder image will be stabilized, irrespective of whether IS is implemented in-lens, in-body .. or even in a dual/hybrid way using both. [Second advantage for in-lens IS being the fact that it's specifically tailored to match a specific lens ... and I do not believe this holds much truth any longer against todays in-body IS systems) 

So while Canon (and Nikon) had a major advantage with their in-lens IS approach during the (D)SLR era, this is coming to an end.

Personally, I would prefer a Canon FF mirrorless system, of course with new, native, short flange-distance lens mount. Ideally with in-body IS, and lenses without any manual focus gears, only "by-wire" in a really well-implemented fashion. Zoom also "by wire". Either turning rings on lenses or really good, highly ergonomical control points on camera body. Ideally also with non-mechanical aperture ... think of something like a variable, highly transmissive LCD with a perfectly round aperture opening at all openings .. also implemented in body, rather than in evry lens. 

To complete my vision of future "solid state" mechanics-free FF-sensored cameras, shutter would be fully electronic. 

If the in-body IS could be extended to "6 axis", i.e. adding linear movement in the Z-axis [current 5-axis systems (Oly) allow linear and rotational moves in the X and Y axis and rotational moves around the Z axis] ... then focussing could possibly also take place in the body, without any moving lens elements. With proper lens construction, that is. 

This would possibly allow for camera/lens systems with significantly smaller, lighter, simpler, more robust, fully weathersealed, higher IQ [only needs to be adjusted/centered once before leaving factory] lenses ... at significantly lower production cost ... and hopefully prices. 8)

Not sure however, whether I'll live long enough to get it from Canon. 


Meanwhile I do expect Canon to come up with in-lens IS in fast primes as well. 50/1.4, 50/1.8, 85/1.8 + 100/2.0 are all very old lens designs and in need of a major overhaul, with the same treatment Canon gave the 24/28/35 IS primes. Not only IS and (corner) sharpness, but also less (lonigtudinal) CAs, please.


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## GMCPhotographics (Jun 25, 2014)

I have a 400mm f2.8 LIS. It's a fast prime and it's got an image stabiliser.
I have a 24mm f1.4 L, it doesn't need and IS unit because it can be shot hand held at 1/25th second easily and due to it's huge light gathering capabilities, it can shoot at light levels several stops below what an f2.8 lens can achieve. So what could an Is offer a 24mm f1.4? Very little.


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## AvTvM (Jun 25, 2014)

GMCPhotographics said:


> I have a 400mm f2.8 LIS. It's a fast prime and it's got an image stabiliser.
> I have a 24mm f1.4 L, it doesn't need and IS unit because it can be shot hand held at 1/25th second easily and due to it's huge light gathering capabilities, it can shoot at light levels several stops below what an f2.8 lens can achieve. So what could an Is offer a 24mm f1.4? Very little.



2 stops [2.8 - 2.0 - 1.4] ... to be precise. ;D

IS would not hurt, even on f/1.4 lenses. Not everyone shoots them fully open ALL the time. Sometimes a bit more DOF is desirable. Or 2 stops closed (f/2.8) for IQ. etc.


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## endiendo (Jun 25, 2014)

I think people want absolutely IS, but don't know why..

Cameras have good higher and higher ISO..
Very good lens have a lot of light...

-> you can have enough light for fast speeds (> 1/100 or 150)... So why do we bother for IS.... 
I was useful when camera couldn't go (good) over ISO400.. but know, IS is more and more useless.

I see utility only for long lenses.


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## GMCPhotographics (Jun 25, 2014)

AvTvM said:


> GMCPhotographics said:
> 
> 
> > I have a 400mm f2.8 LIS. It's a fast prime and it's got an image stabiliser.
> ...



If i wanted sharp stopped down photos I'd use a 24-70IIL. 
An is usint would only degrade IQ at f1.4 by introducing extra glass elements into the lens forumla. I was my farst primes as sharp as possible wide open....if not then there's little point to it. if you are going to stop down, then there's no need for a bag od heavy fast primes...a 16-35 and a 24-70 would be lighter, more versatile and cheaper.


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## GMCPhotographics (Jun 25, 2014)

AvTvM said:


> 2 stops [2.8 - 2.0 - 1.4] ... to be precise. ;D



Ok, hair splitter....several means more than one... 
2 Stops is more than 6 clicks on a dial. It bumps shutter speed to x4 at teh same iso, which is a huge benefit.
So lets take an exposure of f1.4 @ iso 6400 @ f1/25th. at f2.8, I would get a shutter speed of 1/6th of a second....pretty slow.

I shot a wedding by candle light in a church crypt a few years back...f2.8 just wasn't possible. but due to f1.4 and f1.2 glass, I could get shutter speeds of 1/50th and 1/100th second at ios 6400. No flashes were allowed and during the service, shutter speeds of less than 1/50th would have been riddeled with motion blur by the targets in the photos.


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## Maximilian (Jun 25, 2014)

endiendo said:


> I think people want absolutely IS, but don't know why..


Hi endiendo!

I could also live without IS (most of the time) and so I can understand your opinion. 
But if useful tech is available at a reasonable price, size and weight, why avoid it?

I can remember a picture I took of a young Siberian tiger in really dim light at the zoo. 
It was at ISO 3200, 400 mm and 1/20 s, handheld.
I still don't know how I and/or the IS could manage to get it quite sharp.
But I am sure that it was not my (non existing) sniper ability but more to the IS.


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## GMCPhotographics (Jun 25, 2014)

Maximilian said:


> endiendo said:
> 
> 
> > I think people want absolutely IS, but don't know why..
> ...



Which again shows that the IS merit is stronger at the longer focal lengths and less so for the wider focal lengths.


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## AvTvM (Jun 25, 2014)

yes, agreed. 

I've sold my 2 "fast" primes [50/1.4, 100/2.0] recently and rely solely on my f/2.8 workhorse Zooms [17-55, 70-22 II]. Occasionally I do like the capability for shallow(er) DOF (on APS-C), but got sick and tired of the very high amounts of loCA (bokeh fringing; purple/green) of these old lens designs ... and am not prepared to shell out a grand or more for optically better fast primes [L]. 
IF I move to FF and stick with Canon, I'll definitely get the 24-70 2.8 II as well. Although IS would really be welcome on that one, too!


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## Maximilian (Jun 25, 2014)

GMCPhotographics said:


> Which again shows that the IS merit is stronger at the longer focal lengths and less so for the wider focal lengths.


I totally agree. 
And If I had enough money for the 24-70L 2.8 II then I would preferably take this one instead of its prototype brother with IS because of size and weight.


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## aznable (Jun 25, 2014)

AvTvM said:


> yes, agreed.
> 
> I've sold my 2 "fast" primes [50/1.4, 100/2.0] recently and rely solely on my f/2.8 workhorse Zooms [17-55, 70-22 II]. Occasionally I do like the capability for shallow(er) DOF (on APS-C), but got sick and tired of the very high amounts of loCA (bokeh fringing; purple/green) of these old lens designs ... and am not prepared to shell out a grand or more for optically better fast primes [L].


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## AvTvM (Jun 25, 2014)

Maximilian said:


> And If I had enough money for the 24-70L 2.8 II then I would preferably take this one instead of its prototype brother with IS because of size and weight.



urban legend ... just look at the difference in size and weight between EF 70-200/4 L vs. 70-200/4 L IS ... identical in size, 55 grams more weight. And ... even better IQ for the IS version. 

4 L ... 76x172mm - 705g
4 L IS ... 76x172mm - 760g

Other than for Super-Teles with huge glass elements, in-lens IS units are quite light, compact do not add a lot of production cost ... although it may add a lot on retail prices. ;-)


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## Maximilian (Jun 25, 2014)

AvTvM said:


> Maximilian said:
> 
> 
> > And If I had enough money for the 24-70L 2.8 II then I would preferably take this one instead of its prototype brother with IS because of size and weight.
> ...


Okay. I suppose both of us didn't have one to compare, but the "urban legends" spread here sounded reasonable.



> just look at the difference in size and weight between EF 70-200/4 L vs. 70-200/4 L IS ... identical in size, 55 grams more weight. And ... even better IQ for the IS version.
> 
> 4 L ... 76x172mm - 705g
> 4 L IS ... 76x172mm - 760g


here you are right.
But if you compare the unequal 17-40/4 L to the 16-35/4 L IS it looks different.

So I would extend my statement to "... instead of its prototype brother with IS because of its *expecteted bigger *size and weight. *Otherwise I would take an IS version, if it's not too expensive and does not lose too much IQ.*"
More precise now?


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## GMCPhotographics (Jun 25, 2014)

There is an upward trend in weight with the L lenses. I'm ignoring the newer mkII super tele's here. But generally there is an upwards trend. The mkII 70-200 f2.8 LIS is heavier, the 16-35 f4 LIS is heavier and larger than the 17-40L. While the newer 24-70IIL is lighter and smaller, it's a different optical design and the old one was over engineered for sure. 
The 70-200 f4 LIS vs the 70-300 LIS....that new lens is actually quite heavy compared to the old 70-200 f4 LIS. The 70-200 f4 LIS is a really sweet lens, it's so impressively light. But I don't think it's upto the ruggedness of the f2.8 version. The f2.8 version has a number of metal parts to it's casing, where as the f4 is all plastic, including where colar to which the hood fits. I'm not putting the f4 lens down, just stating a few observations about it. I think the newer and heavier L's are being built to a higher robustness and are heavier as a consequence. I don't think adding an IS unit to the formula adds much weight, but adding lots of new elements to make it sharper and then making the mechanism stronger by using more metal must increase the weight significantly.


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## sdsr (Jun 25, 2014)

endiendo said:


> I think people want absolutely IS, but don't know why..
> 
> Cameras have good higher and higher ISO..
> Very good lens have a lot of light...
> ...



While it's true that high ISO performance is good on newer cameras, it's still the case that image quality is better with lower ISOs (esp. if you want or need to crop, and esp. with smaller sensors); so IS/IBIS can be useful even with short, fast primes. Unless there's clear evidence that putting IS in a very fast lens reduces its image quality, I really don't understand why people object to the idea.


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## bdunbar79 (Jun 25, 2014)

sdsr said:


> endiendo said:
> 
> 
> > I think people want absolutely IS, but don't know why..
> ...



+1

I've been in situations where I'm at 1/125s, f/2.8, and ISO 8000 and shooting stationary objects. If IS lets me lower my shutter speed so that ISO is 2000, then that is a very good thing.


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## mackguyver (Jun 25, 2014)

I've got steady hands and don't see a huge need for IS in fast lenses where I'm usually shooting wide open, but I would definitely be first in line if Canon releases an updated 135 f/2 with even sharper optics and IS ;D


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## dgatwood (Jun 25, 2014)

Grumbaki said:


> sdsr said:
> 
> 
> > By the way, there are *some* fast primes with IS - e.g. Sony makes some 1.8 APS-C e-mount primes that have it (35mm & 50mm; maybe others).
> ...



May not be fast, but it has a nasty bite. I hear the lens is fit for a queen, though.




GMCPhotographics said:


> I have a 400mm f2.8 LIS. It's a fast prime and it's got an image stabiliser.
> I have a 24mm f1.4 L, it doesn't need and IS unit because it can be shot hand held at 1/25th second easily and due to it's huge light gathering capabilities, it can shoot at light levels several stops below what an f2.8 lens can achieve. So what could an Is offer a 24mm f1.4? Very little.




Because fast is never fast enough. Some of us like to shoot sports at night without artificial lighting. 

But in all seriousness, as other folks have said, for every stop that IS buys you, you can take the same shot with one stop less ISO gain and the loss of dynamic range that comes with it. And when you're dealing with the sort of poor lighting where f/1.2 is most critical, the noise starts to matter. IS on a fast lens gives you the ability to trade shutter speed for less noise. Whether you're doing that at f/1.2 or f/4 is immaterial; the advantage is still the same.


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## davidcl0nel (Jun 25, 2014)

35 IS can be used to 1/4sek most of the time, maybe 80% are successful.
For non moving objects this is fantastic. Something in a museum with ISO800 and 1/4 or ISO8000 and 1/40 - what gives you a better image?

So a 24 IS can be used to 1/2sek, maybe more. 24 1.4 with ISO800 f/2 should be sufficent to use it in any night handheld, and you can leave the tripod one more time at home...


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## Mr_Canuck (Jun 25, 2014)

I used both Sony and Pentax before switching to Canon this year. I'd say that I'm happiest with my system now... except I didn't realize how much of a benefit was sensor-shift shake reduction in both Pentax and Sony. Currently, any lens you use will be IS with their systems. But then you put up with noisy and slow screw driven lenses on way too many of their lenses.


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## Deleted member 91053 (Jun 25, 2014)

I don't know why Canon's fast (short) primes don't have IS - but I hope this continues to be the case.
My concern with IS is that it introduces a dead element in the focal path (this is my description for a piece of glass that does nothing) also IS slows up AF acquisition. On longer lenses (300mm +) then I agree that IS can be handy (to have in reserve) though I very rarely use it these days.
Back in January I turned off the IS on My Canon 800 F5.6 L IS and was happier without it. AF is faster and I have had no problems regarding shutter speeds (note I use ISO's of up to 12800) also due to the improved AF my "Hit Rate" is higher. Since then I have turned off the IS on all my IS lenses (300 F2.8 L IS, 70-200 F2.8 L IS and 24-105 L IS) and have noticed similar improvements. IS can be handy to have in reserve but on my 300 F2.8 and shorter lenses I really don't have much use for it, on the 800mm it can be handy for Dawn/Dusk shots but as soon as the light is near passable I turn it off.
Just my 2p.


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## bdunbar79 (Jun 25, 2014)

johnf3f said:


> I don't know why Canon's fast (short) primes don't have IS - but I hope this continues to be the case.
> My concern with IS is that it introduces a dead element in the focal path (this is my description for a piece of glass that does nothing) also IS slows up AF acquisition. On longer lenses (300mm +) then I agree that IS can be handy (to have in reserve) though I very rarely use it these days.
> Back in January I turned off the IS on My Canon 800 F5.6 L IS and was happier without it. AF is faster and I have had no problems regarding shutter speeds (note I use ISO's of up to 12800) also due to the improved AF my "Hit Rate" is higher. Since then I have turned off the IS on all my IS lenses (300 F2.8 L IS, 70-200 F2.8 L IS and 24-105 L IS) and have noticed similar improvements. IS can be handy to have in reserve but on my 300 F2.8 and shorter lenses I really don't have much use for it, on the 800mm it can be handy for Dawn/Dusk shots but as soon as the light is near passable I turn it off.
> Just my 2p.



That's why I don't shoot moving objects or sports with IS. I shut it off on my 300 and 400 f/2.8's because my miss rate increased with IS turned on.


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## Deleted member 91053 (Jun 26, 2014)

bdunbar79 said:


> That's why I don't shoot moving objects or sports with IS. I shut it off on my 300 and 400 f/2.8's because my miss rate increased with IS turned on.



+1
That's exactly what I was getting at, only you said it with FAR fewer words!
Additionally I really find little use for IS on stationary subjects unless the light is stupidly low!


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