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Fedgrub
27-04-2012, 1:50pm
I was taking a look at zoom lenses after using my friend's 100-400 the other weekend, and noticed that many of them don't have IS. I know the 70-200 2.8 has an IS version (at a significant cost) but a lot of the others don't have an IS version.

I would have thought that IS would be even more important in a lens with a longer focal length.

Is there a reason for not having IS in these lenses? Do you find that it makes shooting difficult without it?

Thanks in advance

Arg
27-04-2012, 2:51pm
Give examples please.

Some Canon lenses are old designs eg the 400mm f5.6 and simply pre-date IS.

Xenedis
27-04-2012, 9:35pm
In the Canon world, plenty of zooms have IS, and not necessarily telephoto zooms.

The EF 24-105mm f/4L has IS, as does the EF-S 17-55mm f/2.8. There are numerous other lenses.

As for why a lens manufacturer would choose not to include IS in a lens, it basically comes down to quality and cost.

IS increases the optical complexity of a lens. It requires more optical elements, which adds weight, bulk and design considerations, which ultimately translates to cost.

In the case of the EF 70-200mm zooms lenses, there are four varieties.

There is an f/2.8 version and an f/4 version, and also a version of each with IS.

sunny6teen
27-04-2012, 9:50pm
I would have thought that IS would be even more important in a lens with a longer focal length.



how long are we talking? if the lens is too large to hold...IS is pretty irrelevent.

ricktas
28-04-2012, 7:06am
Up until about 10 years ago IS/OS/VR (whatever you like to call it) did not exist. Every photo taken before then was done so without it. Can it be a benefit? yes! Is it necessary? No.

If you are using a longer lens, use a tripod or monopod, as has been done for generations. Just cause a lens doesn't have IS doesn't mean it is not a brilliant lens. There are a lot more factors to good photos, than a single feature that a lens may or may not have.

Xenedis
28-04-2012, 9:34am
Up until about 10 years ago IS/OS/VR (whatever you like to call it) did not exist.

Actually, IS goes back 17 years.

Canon first introduced IS in 1995 with the introduction of the EF 75-300mm f/4-5.6 IS USM.

ricktas
28-04-2012, 9:40am
Actually, IS goes back 17 years.

Canon first introduced IS in 1995 with the introduction of the EF 75-300mm f/4-5.6 IS USM.

Thanks for the info. I was just guessing my dates, based on when they became popular, which would have been the early 2000's

Xenedis
28-04-2012, 9:51am
Thanks for the info. I was just guessing my dates, based on when they became popular, which would have been the early 2000's

From memory, Canon was the first manufacturer to introduce the technology.

I'm not sure when Nikon and the others first brought out their stabilisation systems, but certainly over the last decade IS has been more prominent and popular, as indeed have DSLRs.

The first IS lens I bought was in 2005.

Fedgrub
28-04-2012, 4:38pm
how long are we talking? if the lens is too large to hold...IS is pretty irrelevent.

This is a good way to put it.

Thanks everyone for the replies. It's more about my shaky hands, I don't have a medical condition or anything but my hands are shakier than normal so I was wondering whether there was a technical reason why IS doesn't come on a lot of lenses, but it seems to be a time thing. Would be nice to get the 70-200 with IS, but it's so damn expensive. Might have to tripod it with the non-IS.

bricat
28-04-2012, 10:28pm
I know what is cheaper but what is heavier to lug? tripod or IS

vk2gwk
29-04-2012, 11:37am
When using "long" lenses there is a limitation on the usuable shutter speed of: T = 1 / focal length . So on a full frame camera and a 400mm telephoto lens you need at least 1/400" (and on a APS-C even 1/640"). This means that already "wide open" you'll have to increase your ISO in low light which can be a disadvantage (noise!). The Image Stabilisation brings this down 2 - 3 stops so that you can shoot at 1/50" - 1/100" (if the subject is stationary) without a worry about camera shake. I tried it out with my 100-400mm lens at 400mm as I am considering a 70-200mm L and wanted to check if I could do without the IS. The test shots showed that the IS really works - even when you think you hold your gear pretty steady! So I am going to save a little bit longer to get the IS version :)

Xenedis
29-04-2012, 11:49am
When using "long" lenses there is a limitation on the usuable shutter speed of: T = 1 / focal length .

This isn't a limitation; it's a very general rule-of-thumb to be used as a guideline.

The minimum shutter speed required to ensure a sharp shot depends on a number of factors, such as:


the available light;
the focal length of the lens;
the weight and weight distrbution of the lens;
whether the subject is moving;
the lens handling technique of the user;
whether there's any wind; and
whether the shooter is on unstable terrain (eg, jetties, boats, etc.).

Speedway
29-04-2012, 2:51pm
So on a full frame camera and a 400mm telephoto lens you need at least 1/400" (and on a APS-C even 1/640").
This is a common misconception to the Rule-of-Thumb Guideline. The focal length of the lens doesn't change just the sensor size. The image projected onto the sensor is the same, jut cropped differently by the sensor size, so the shutter speed requirement doesn't alter.
Keith.

Xenedis
29-04-2012, 4:29pm
This is a common misconception to the Rule-of-Thumb Guideline. The focal length of the lens doesn't change just the sensor size. The image projected onto the sensor is the same, jut cropped differently by the sensor size, so the shutter speed requirement doesn't alter.
Keith.

The smaller image circle projected onto an APS-C sensor by a 135-format lens means that the subject matter is larger within the confines of the frame.

This means that movement of subject matter (either that of the subject itself, or photographer-induced) will therefore traverse more of the frame and make blur more apparent, so to compensate you would need to base your minimum shutter speed on the focal length multiplied by 1.6 (Canon), 1.5 (Nikon) or 2.0 (Olympus and some others).

Speedway
29-04-2012, 7:32pm
The smaller image circle projected onto an APS-C sensor by a 135-format lens means that the subject matter is larger within the confines of the frame.

This means that movement of subject matter (either that of the subject itself, or photographer-induced) will therefore traverse more of the frame and make blur more apparent, so to compensate you would need to base your minimum shutter speed on the focal length multiplied by 1.6 (Canon), 1.5 (Nikon) or 2.0 (Olympus and some others).

No the image circle is the same for both FF and crop sensor cameras, the camera just puts a smaller sensor in that circle meaning the edges are cropped more, the movement within the actural circle remains the same. In other words the sensor just crops the same image to suit giving the impression of an enlarged image. If you had an object move 100mm then if the movement on the FF sensor was 1mm then the movement on the crop sensor would be the same, 1mm.
Keith.

Bennymiata
29-04-2012, 7:45pm
Personally, I like to have IS on all my lenses.
It is defintely a benefit, and apart from price, is rarely a disadvantage.

Canon are bringing out new 24mm and 28mm prime lenses with IS shortly.

unistudent1962
29-04-2012, 8:08pm
Canon are bringing out new 24mm and 28mm prime lenses with IS shortly.

And yet they didn't put it on the new 24-70 f2.8.
Apart from cost, has anyone got any theories behind Canon's reasoning on this?

Xenedis
29-04-2012, 8:37pm
No the image circle is the same for both FF and crop sensor cameras

The imaging circle is actually a property of the sensor's length and width; specifically, the diameter of the imaging circle is the diagonal dimension of the focal plane (ie, sensor or film).


the camera just puts a smaller sensor in that circle meaning the edges are cropped more

In actuality the image projected onto the sensor by a full-frame lens is a smaller image than what the lens is able to project.


the movement within the actural circle remains the same.

Moving subject matter will traverse more distance across the APS-C frame.


In other words the sensor just crops the same image to suit giving the impression of an enlarged image.

If subject matter has less distance to move from one edge to the other (which it does when projected onto an APS-C sensor by a 135-format lens), its movement will appear more pronounced, as it will traverse a higher percentage of the available frame space.


If you had an object move 100mm then if the movement on the FF sensor was 1mm then the movement on the crop sensor would be the same, 1mm.


1mm out of 22.5mm is a higher percentage (0.044%) than 1mm out of 36mm (0.027%); therefore, the subject matter travels across a larger portion of the frame, meaning that blur will be more apparent.

Xenedis
29-04-2012, 8:40pm
And yet they didn't put it on the new 24-70 f2.8.
Apart from cost, has anyone got any theories behind Canon's reasoning on this?

Perhaps to avoid cannibalising the market for the 24-105/4L IS.