Canon kit 18-55mm versus much more expensive 15-85mm

davidhq · Mar 17, 2013

Hi!

I am testing my new expensive 15-85mm lens versus the kit lens. I have Canon 450D....

I the test shots below I used f/8 ISO 200. My question: I barely see the difference in quality except in one example (first two photos). Is this normal? Do you see more difference? There is probably some difference in contrast in other pictures too, but I think it's neglible. I don't see the difference in sharpness at all...

Would there be more difference in different conditions? Please let me know!

Regards,
David

davidhq · Mar 17, 2013

PS: 15-85 is always the first picture of the pair...

CouncilmanDoug · Mar 17, 2013

most lenses are perfectly fine at f8, it's when you're shooting with larger apertures you might notice a difference

davidhq · Mar 17, 2013

Hi! Thank you for the answer... I previously compared them at f/5.0 but didn't notice that much difference either...

The only reason why it's strange to me is because I read the following on the forums:
The image quality of the 15-85mm is miles better than the 18-55mm IS lens.

I have both lenses used with a 50D and can say without question the 15-85 is far superior.

The image quality of the 15-85 It is absolutely far better than the 18-55.

I own both lenes and can say that the 15-85 has much better resolution than the 18-55.

So is all of this BS or what? :|

imagemaker46 · Mar 17, 2013

If the kit lens is anything like the kit lens I have sitting here, it feels like an empty plastic tube without glass. The kit lens is good for shooting lots of things, but it isn't really a very strong lens. There are usually reasons why more expensive lenses are more expensive, the glass quality, construction and sharpness. Try shooting a group shot with 40 people using both lenses and then have a good look at the faces, you will see the difference in overall quality from the non-kit lens.

tirediron · Mar 17, 2013

Moving to the Canon Lens forum.

tirediron · Mar 17, 2013

While I'm not a Canonite, so I can't speak with first-hand knowledge, in general, almost any lens will turn in a decent result under average conditions (and those are certainly average conditions in your test shots). The real difference comes in extremes. Shoot each wide open at max and min aperture. Do some low-light comparisons, and of course, as Scott mentioned, there's the whole build-quality issue as well. It might not seem like it at first glance, but with good glass, you almost always get what you pay for!

daggah · Mar 17, 2013

I thought the 17-55 was Canon's high quality f/2.8 zoom, not some "kit" lens.

TCampbell · Mar 17, 2013

The "kit" lens is usually an EF-S 18-55mm f/3.5-5.6 IS. The EF-S 17-55 f/2.8 IS USM is a MUCH nicer lens.

Were you meaning to refer to the 18-55 when you said "kit" lens?

Also... in tiny web-size images, every lens looks equal (you can hide a lot of flaws when the image is tiny). To compare, you'd need 100% crops. Also you'd want to check the difference between image quality at center vs. image quality off to the edge or corners.

Both lenses would need to be shooting at equal f-stops which are near wide-open. Suppose you had an f/4 lens and an f/2.8 lens... the f/4 might look better... it might even score better MTF curves. But if you stop down the f/2.8 lens to f/4 and compare both lenses at f/4 and it'll completely change everything (which is one of many reasons why it's dangerous to compare MTF curves when lens shopping.)

davidhq · Mar 19, 2013

Thank you for the answer! Yes, I ment 18-55 when I said kit lens..

I will do more tests and hopefully I'll be able to see more difference...

thank you!
david

TCampbell said:
The "kit" lens is usually an EF-S 18-55mm f/3.5-5.6 IS. The EF-S 17-55 f/2.8 IS USM is a MUCH nicer lens.

Were you meaning to refer to the 18-55 when you said "kit" lens?

Also... in tiny web-size images, every lens looks equal (you can hide a lot of flaws when the image is tiny). To compare, you'd need 100% crops. Also you'd want to check the difference between image quality at center vs. image quality off to the edge or corners.

Both lenses would need to be shooting at equal f-stops which are near wide-open. Suppose you had an f/4 lens and an f/2.8 lens... the f/4 might look better... it might even score better MTF curves. But if you stop down the f/2.8 lens to f/4 and compare both lenses at f/4 and it'll completely change everything (which is one of many reasons why it's dangerous to compare MTF curves when lens shopping.)

Big Mike · Mar 19, 2013

I changed the title to 18-55mm.

There is a Canon 17-55mm lens with a maximum aperture of F2.8 and IS. I think that if you tested this one, you'd find it to be much, much better. And if you compared the kit lens to something like the 35mm F1.4 L, you would find it to be much, much, much better.

But all that being said, the best way to improve anyone's photos, is to improve the photographer (knowledge, skill, talent & technique).

davidhq · Mar 19, 2013

Mike,

so you're saying that comparing the kit lens to 17-55 would yield very different results but comparing the kit to 15-85 not so much? I thought that 15-85 and 17-55 are more or less equal in overall IQ (when there is enough light)?

Big Mike said:
I changed the title to 18-55mm.

There is a Canon 17-55mm lens with a maximum aperture of F2.8 and IS. I think that if you tested this one, you'd find it to be much, much better. And if you compared the kit lens to something like the 35mm F1.4 L, you would find it to be much, much, much better.

But all that being said, the best way to improve anyone's photos, is to improve the photographer (knowledge, skill, talent & technique).