Image quality of the new 18-200mm lenses for APS-C size sensors

[richard_arthur]

Any educated guesses on how the image quality of the new 18-200mm

lenses designed for DSLR's with APS-C size sensors will compare with

image quality of the existing 28-200mm lenses for full-frame DSLR's

and 35mm SLR's? I am thinking of buying Canon's EF 28-200mm lens

for everyday use because at this point I have only Canon "L" lenses,

and I find myself leaving the camera at home too often because the

lenses are so heavy. I have looked at a lot of photos on various

websites taken with the EF 28-200mm lens, and to my eyes, the

quality seems to be acceptable for everyday use.

 

However, I see that Sigma, Tamron, and Minolta have all announced

new soon-to-be-shipping 18-200mm lenses designed especially for

cameras with APS-C size sensors. I would like to have the extra

10mm at the wide end of the zoom range, but image quality is

important to me. Any reason to think that the image quality with

these lenses will be either better or worse than quality of the

existing 28-200mm lenses?

 

Also, will these lenses even be useable with the Canon 10D? If I am

not mistaken, Canon's EF-S lenses designed for APS-C size sensors

can be mounted on the 20D, but not the 10D. So will the Sigma and

Tamron lenses be compatible with the 10D or only with the 20D?

[._kaa]

<p><i>and to my eyes, the quality seems to be acceptable for everyday use</i>

 

<p>Define acceptable quality.

 

<p>For some people that's what a magazine editor will accept for a double-spread layout. For other people that's what will make a nice 200x300 pixels web picture.

[jimstrutz]

Well, 18-200mm lenses are designed more to fill the function of a 28-300mm lens on a film camera, not a 28-200mm, and their max aperture at the long end is less than f/5.6. So I would guess that they will perform more like a 28-300mm than a 28-200mm. Generally people claim that the image quality of the 28-200mm class lenses are a bit better than image quality of 28-300mm lenses. So at the long end I would suspect that the 28-200mm lens would be superior to the 18-200mm lens. This is just a guess though, as these super zoom lenses have been getting better with each itteration. Of course from 18-27mm the digital specific lens would be better. :)

 

These are not EF-S mount lenses. They won't cover the whole field of a full frame camera, but they will fit on one. They will work fine on the 10D.

 

Another option would be the Sigma 18-125mm. Claims are that it is surprisingly good, and fills the slot of a 28-200mm lens would on a film camera.

 

FWIW, optically the Canon EF 28-200mm is consistently rated at the bottom of the 28-200mm lenses being offered today. It's not a horrible lens, but I'd get the Tamron if I was looking for one.

[richard_arthur]

Jim, thanks for your reply. You suggested (if I may paraphrase) that the optics of the 18-200mm lenses may be comparable to those of 28-300mm lenses for full-frame SLR's. I understand that with the multipler effect of APS-C size DSLR's, an 18-200mm lens equates to roughly the same zoom range as a 28-300mm lens for full-frame SLR's. However, I don't see any reason to think that this would mean that the optics would be similar unless the 18-200mm lenses are constructed similarly to the 28-300mm lenses, and I don't know that this is the case. (Does anyone know?) Can someone explain to me why it makes more sense to compare the optics of the 18-200mm lenses to the optics of 28-300mm lenses for full-frame SLR's rather than the optics of 28-200mm lenses?

 

If anyone can give a good reason to think that the image quality of the 18-200mm lenses will be similar to the existing 28-300mm lenses then that will make the decision easy for me. The quality of the photos I've seen that were taken with 28-300mm lenses is lower than what I'm willing to accept.

 

BTW, I've also seen the charts where the Canon EF 28-200mm lens ranks below the other 28-200mm lenses in optical tests, but my choice of the Canon EF 28-200mm lens over those from Sigma or Tamron is based on viewing actual photos...well, web photos anyway. There are a few websites (e.g., Photosig and Pbase) where you can search for photos taken with a particular lens. To my eye, photos with the Canon EF 28-200mm lens are generally better than those from other 28-200mm lenses. Granted, this is far from an ideal way to compare image quality between different lenses, but I trust it more than some lens score based on scientific optical tests.

 

And Kaa, I don't see any need to define "acceptable quality" since I am just talking about what is acceptable to me personally, for my own uses.

[richard_arthur]

BTW, thanks for the suggestion on the Sigma 18-125mm. I will take a look.

[ron c sunshine coast,qld,a]

I used the canon 28-200 recently and understand what you mean about 'aceptable quality'.It really isn't too bad i say.I wouldn't own one myself because i have no issues with carrying two lenses but i do tend to think that some people like to bag this lens just for the sake of it

<BR>The sigma 18-125 does indeed get some good reviews,but as allways it's relative-here is a good comparison with a canon 17-85 IS lens.That sigma looks VERY average at certain focal lengths.

<BR>Note that you can download full size files

<P>http://www.pbase.com/franklin/canon_sigma

[jimstrutz]

The reason I would suggest that 18-200mm lenses would be similar to 28-300mm lenses is zoom range. There both 11:1 zoom lenses compared to 7:1 zoom lenses (18-125mm & 28-200mm). It appears that extended zoom range is one of the most difficult things to accomplish while maintaining optical quality.

 

There are other things to look at as well. For instance the increased number of optical elements (can reduce contrast & increase flare), as well as the maximum aperture at the tele end (requires faster shutter speeds & reduces AF sensitivity).

 

However, This is all just speculation. To be even partly difinitive you would have to compare actual lenses. And since these these are NEW lens designs in a field where optical quality is generally increasing, they might be quite good. I remain skeptical until I hear otherwise for a number of sources.

[richard_arthur]

Thanks again for your replies and especially to Jim for the suggestion on the Sigma 18-125mm. After looking at a lot of sample shots, I have decided that's the lens I will go with. Seems like a great lens for the price, and the light weight and size is just what I want. I plan to drop the camera in a knapsack and carry it around pretty much everywhere I go, unless I know for sure that I will be taking photos, and then I will take along my other lenses instead. Also, for the type of shooting I'll be doing with this lens it will probably be more important to have the extra range at the wide end (vs. the 28-200mm lenses) than at the telephoto end.

[yakim_peled1]

>> I am thinking of buying Canon's EF 28-200mm lens for everyday use because at this point I have only Canon "L" lenses, and I find myself leaving the camera at home too often because the lenses are so heavy.

 

 

Do you have the 17-40/4 and 70-200/4? If so, do you consider them heavy as well? Have you considered primes? If so, which are your favorite focal lengths? All primes below 150mm (excluding the 135/2) are extremely light.

 

>> image quality is important to me.

 

That's hardly surprising, for someone with L lenses.

 

>> The quality of the photos I've seen that were taken with 28-300mm lenses is lower than what I'm willing to accept.

 

Again, for someone with L lenses, I find it hard to believe that you will find the quality of any hyperzoom as acceptable.

 

Happy shooting,

Yakim.