The Problem With Zooms

It is common knowledge that zoom lenses have always been a compromise between focal length range and image quality as opposed to primes..

I have found this since getting my 50D that one lens in particular that I own is tack sharp in my 20D but needed AF Micro adjustment on my 50D to get the best out of it.. I have also been reading the same problems from other photographers on their 50Ds and lately on 7Ds.. To me it appears the problem isn't the camera nor the lens alone but the combination of camera and lens..

I'm wondering since the release of high MP ASP-C sensor cameras like the 50D and 7D that a redesign of zoom lenses is needed.. Lenses that are fine with lower MP cameras just aren't performing to their best with higher MP crop sensor cameras.. Is this also a problem with full frame sensors??

My question is, have the current design of zoom lenses run their course or do we need a redesign of zooms for the current crop of high MP cameras and cameras yet to be released??

Or maybe Canon isn't calibrating the bodies as much any more, figuring the user can do it themselves??

I'm just sayin'...

yogestee wrote in post #9198352
My question is, have the current design of zoom lenses run their course or do we need a redesign of zooms for the current crop of high MP cameras and cameras yet to be released??

Unless a new body is actually misfocusing, there is no way that a higher pixel camera actually makes a lens softer.

Try making the same size print from the 20D and 50D and see which is sharper. If the 20D is sharper, I guarantee that the 50D is missing focus.

The only reason higher pixels 'demand' better lenses is when you look at 100% crops. And in that case the 100% crop of the 50D represents a much, much larger final image.

It's like looking at an 13x20 from the 20D and comparing it to a 20x30 from the 50D.

You might be right since i havent heard too many complaints from the 7D users with the new 15-85mm IS USM unless you have. We will probably always hear complaints concerning 3rd party lenses but your point is well taken in regards to past Canon products paired with new bodys. One thing for sure if their is any validity to your speculation Canon would never admit it !

Regards,

I shoot a lot of low light/high ISO photography, therefore I use wide apertures alot..

For example with my Sigma EX 50-150mm f/2.8 APO at 150mm using f/2.8 on my 20D the images are sharp and I have a high keeper rate.. On my 50D at these settings many images are soft therefore fewer keepers even with shutter speeds over 250th second..

Let me explain.. I returned from a shoot last week using my 50D/Sigma 50-150mm f/2.8.. Most of the images shot at 150mm or there abouts @ f/2.8 were softish..

I was totally pissed off with myself.. I placed my 50D/Sigma 50-150mm on a tripod with shutter remote opened up to f/2.8 zoomed out to 150mm and shot my usual target which is roughly the same distance I shoot my subjects.. Bingo,,sharp images..

I'm still scratching my head over this one..

Are you experiencing the same softness with any of your other lenses that dont have OS zoomed out to their max.[100mm or more] or is it just the 50-150mm handheld on the 50D.

The sigma 50-150mm on SlrGear`s test results shows to be soft wide open at f2.8 but sharp at f5.6 at 150mm. But that doesnt explain why your 20D proves otherwise.

http://www.slrgear.com …t.php/product/1​156/cat/31

A higher density sensor will show more evidence of camera blur/shake for the same lens/shutter speed so at the pixel level it will not be as sharp or rather, depending on conditions, may not be as sharp. This is where pixel peeping becomes dangerous since actually printing at the same size will not show this.

Resize the 50D images down to 20D size and then view them at 100%. They should be as "sharp", discounting other differences such as AA filter, etc.

bohdank wrote in post #9198785
A higher density sensor will show more evidence of camera blur/shake for the same lens/shutter speed so at the pixel level it will not be as sharp or rather, depending on conditions, may not be as sharp. This is where pixel peeping becomes dangerous since actually printing at the same size will not show this.

Resize the 50D images down to 20D size and then view them at 100%. They should be as "sharp", discounting other differences such as AA filter, etc.

That makes logical sense. Did you experience the same softness scenario when you upgraded your body with any of your previous same lenses handheld over 100mm without IS?

It's only with my Sigma 50-150mm because it's the longest lens I've got..

I can get acceptably sharp images out of my 50-150mm @ f/2.8 at 150mm but I'm having trouble with my 50D hand held,, on a tripod no problem at all.. Most lenses aren't at their best wide open and need to be stopped down a stop or two to get their best..

This is the conclusion I've arrived at.. I might shoot more in sRAW1 and see if there's a difference..

I'm in no way, shape or form slamming my 50D,,it's a brilliant camera, probably the best image quality I've ever gotten out of any DSLR/SLR I've owned or used in 30 years of photography.. Image quality comes very close to medium format film.. But Geezus it's hard work.. Once focus and exposure are nailed, the results are nothing but stunning!!

I know I have had this problem once in a while.
When I want to, I can hold still for a 1/5 second shot, but with IS it becomes almost too easy.

You should really go test shoot at 1/500 or 1/1000 with plenty of light and confirm your still "soft".
Maybe 250 is not fast enough for your personal movement in that occasion.

You could go test a 200mm lens with "IS" and see if you have the same issue.

bohdank wrote in post #9198785
A higher density sensor will show more evidence of camera blur/shake for the same lens/shutter speed so at the pixel level it will not be as sharp or rather, depending on conditions, may not be as sharp.

This would imply that a 5D2 photo would not be as sharp as that from a 5D. Is that the case? I haven't heard that.

tvphotog wrote in post #9201000
This would imply that a 5D2 photo would not be as sharp as that from a 5D. Is that the case? I haven't heard that.

This is a mis-interpretation - this just means that if you're hand-holding the camera while shooting, the more pixel-dense sensors amplify the shake coming from your hands a slight bit more - possibly enough to affect the photos.

The sweeping statement that the 5D2 isn't as sharp as the 5D is incorrect.

Saying that you'd need to brace yourself a tiny bit more when using a long (100mm+) lens on a more pixel-dense sensor is correct, although it's not that huge an effect.

If you're worried, you should already be shooting with a tripod.

the affect seen on the crop bodies that amplifies camera shake is the 1.6x factor,
it is similar to putting a 2x teleconverter on a 100mm lens, which makes it a 200mm lens,
and at 200mm you need a min of 1/200 to take a photo in good light and your own movement not affect the shot.
With a 100mm lens it will be 1.6x = 160mm lens and 1/160 would be a min shutter speed, etc.
That said, often 1/500 is necessary to remove your movement and the movement of the subject
from working to make a slightly blurry image worse than normal.
I can hold still well and take long shutter times fine,
many people cannot and IS will be a big help to them.
IS can help up to 4 stops, so if we just take two stops,
you can shoot with 1/125 and have the stability as if you shot with
a 1/250 shutter speed and is a big help on a long 200mm lens.
4 stops would be shooting at 1/125 and having the affect of 1/500.
wow!

Agamemnon wrote in post #9201015
This is a mis-interpretation.

I don't want to start an argument, but it's not a misinterpretation of bohdank's hypothesis. Both the 5D and the 5D2 have the same size sensor; the 5D2 has twice as may pixels on it.