whats the real score about IS lenses...

people... i need your 2 cents on this...

i noticed that the image taken by the IS lenses looks a bit soft compared to non-IS versions that are really sharp. Is it just me or theres really a big difference in terms of image quality?

jeffylicious wrote in post #3851612
people... i need your 2 cents on this...

i noticed that the image taken by the IS lenses looks a bit soft compared to non-IS versions that are really sharp. Is it just me or theres really a big difference in terms of image quality?

the 70-200L f4 IS is regarded as canon's sharpest zoom, and it is sharper than the non-IS version....especially wide open (i've owned both).

the 17-55 IS is the sharpest zoom that i have used wide open except for the 70-200L f4 IS.

what these lenses have in common is they are canon's newest IS zoom offerings.

the 70-200L f2.8 is regarded as being sharper than the IS version.

ed rader

Where did you notice this?

I certainly haven't. Many IS lenses are not available in any other format, the big exception being the 70-200Ls and some of the cheaper zoom lenses, like 75-300, and certain versions of the 28-105 if I am not mistaken. These lenses with and without IS are every bit as sharp as their counterparts, unless you pixelpeep to the extreme. IS lenses have a few more lens elements, but even so, the 70-200 F/4 LIS is considered the sharper of the two F/4Ls, and with the F/2.8 it is the opposite way. However, as I mentioned, unless you pixelpeep to the extreme, you wouldn't see the diffference, and even then, postprocessing creates more of a difference than any of these lenses do or can do by themselves.

Furthermore, just lens variation within a specific lens model accounts for more differences in IQ than the addition of IS per se, and that is variation either way, as in better or slightly less good IQ.

Kind regards, Wim

ed rader wrote in post #3851640
the 70-200L f4 IS is regarded as canon's sharpest zoom, and it is sharper than the non-IS version....especially wide open (i've owned both).

the 17-55 IS is the sharpest zoom that i have used wide open except for the 70-200L f4 IS.

what these lenses have in common is they are canon's newest IS zoom offerings.

the 70-200L f2.8 is regarded as being sharper than the IS version.

ed rader

thanks wimg and ed. by the way Ed..you are right there especially at the 70-200mm thats why i semi-concluded about this.... i base my findings mostly on the pictures i see on the web or here... it was a bad call for me to judge prematurely. i owned a 28-135mm is and it did not produce sharp pictures... and thats me comparing that to a 24-70mm lens. hehehe thanks for the input. you guys are the greatest!!!!

jeffylicious wrote in post #3851734
thanks wimg and ed. by the way Ed..you are right there especially at the 70-200mm thats why i semi-concluded about this.... i base my findings mostly on the pictures i see on the web or here... it was a bad call for me to judge prematurely. i owned a 28-135mm is and it did not produce sharp pictures... and thats me comparing that to a 24-70mm lens. hehehe thanks for the input. you guys are the greatest!!!!

the 300L f4 is supposed to be sharper than the IS version. i'll bet canon can make a 70-200L f4 as sharp or sharper than the 70-200L f4 IS.

so i don't think it's accurate to say the IS version is sharper. the non-IS version is older and i think newer lenses tend to be sharper.

the IS and non IS versions were made at different times and i think that's the biggest difference.

ed rader

%99 of the sharpness is determined by the settings/photographer, not the lens.

IS will beat a non IS all day long for versatility and GETTING the shot.

I'm trading my brick for a 24-105 (yeah, after I made the opposite trade a few months ago). I don't find the IS on the 24-105 to produce less sharp pictures and in fact, I rely on it for sharpness where a bigger aperture won't do.
Ed's right about bokeh on the brick, but I'll take the f4 and IS over the 2.8 and the better bokeh.

Could it often be a case of people posting pics where IS made a big difference for them and allowed them to get a shot they might not have otherwise, yet it lacks sharpness due to a little blurriness because of the resultant low shutter speed?

Had they posted the same pic without IS under the same conditions it wouldn't have been sharp either... or vice versa, post a pic from an IS lens with settings equal to what you can get by with without IS and you won't see a noticeable difference.

My 70-200 IS is as sharp as can be. It definitely gets the job done for me. Question though. If you turn IS off does that in the sense of what people have found here, make it "as sharp as the non IS" ?

If you are shooting hand held at slower, generally the IS lens will be sharper because of the IS.

Most prime lenses are sharper than equivalent zoom lenses, but this is not always the case. My Sigma 50-500 is sharper than the Sigma 400/5.6 APO that it replaced.

Where a similar lens has both IS and non-IS versions such as the 70-200 f/2.8 or f/4, there is usually very little difference between the two and often there is more variation between different copies of the same lens than between IS and non-IS versions.

You cannot expect a $300 IS lens such as the new 18-55 IS to outperform a $1,500 non-IS lens such as a 24-70 L, but it might if you are shooting hand held at low shutter speeds.

About the 70-200s...

I think the sharpness goes like this

1# f/4 with IS
2# f/2.8 with IS
3# f/2.8
4# f/4

If you go to www.the-digital-picture.com and check out 100% crops from the f/4 IS at 135mm f/4 and the 135mm f/2L at f/4 you'll see that the 70-200 f/4L IS is a tiny winy bit softer than the 135, seriously, the differnce is almost none. The 135 is said to be one of the sharpest lenses in Canon's lineup. The 70-200 f/4L IS would probably go into the sharpest Canon lenses lineup too, and it's a freakin' ZOOMlens!

Take a lens like the 70-200 with and without IS for a day of shooting and you'll come back with many more keepers with the IS lens than without. That is the bottom line. If you want to shoot brick walls in controlled conditions then yes, you might get a sharper photo with the non-IS lens. But when used to take "real" images, the IS lens will provide many more keepers hands down.

Good. B/c I have the IS and was told that it was an amazing lens by reviews and by experts. I can attest to these sources being correct, but I would be mad if I missed out on something better.

I think the versatility of IS outweighs any IQ-loss.
That is...provided that you need IS. Some people don't.

Ok I now have another question. Why would IS reduce image quality?