Does lens quality matter?

[keller]

So I go to the camera store, and see a Canon lens for $1000, and a Sigma lens for only $50, and a Kiron for only $100.

Now, obviously the Canon lens are better, but does it matter? What does lens quality affect? Say I take a photo of a green grass hill with a Canon lens, then a Sigma lens. Will there be much difference in the photos?

[Torus34]

Composition and lighting will have a much greater effect on the impact of the final photo than lens quality, within reasonable limits. There is a real difference between a disposable camera's lens and a good 'prime' lens. You can easily see it in the final print. Even so, it is possible to make a great photograph with a disposable.

[markc]

There's also construction quality to worry about. I wouldn't expect a beginner to see what a pro lens does differently as far as image quality goes, but once a person becomes good enough, it can become important. I personally don't shoot with any of the "L" glass (Canon's pro line), but I did go for the better primes below that. I chose the 50mm/1.4 over the 1.8 because it has better bokeh (the quality of the out-of-focus area in an image). There are also things like chromatic and spectral aberations, flair, barrel distortion, etc. that a pro lens will have less of.

My advice is to try to get a decent lens so that you won't have to upgrade all that soon, but don't break the bank. In the above example, the 50mm/f1.8 is a decent enough (and cheap enough) lens that it's fine for most people. I shoot with a lot of shallow DOF, so the bokeh of the 1.4 lens (which I could see was different) was worth the extra money to me.

[keller]

But with the lens, apart from the durability, how does it affect the photo? Would it alter the colour and accuracy of the photo, or how easily it focuses?

[darich]

My Canon lenses are f2.8 and cost approx £1000 each. You can buy the 70-200 with f4 for several hundred pounds less. So you're paying more money for a faster lens.

I think it has higher quality glass and definitely has a wider aperture which is constant throughout the entire focal range. I can shoot at 200mm and f2.8 - that's what I paid the big money for. Colour or accuracy maybe affected but i think you'd need a computer to measure it because the difference would be so small.

It may well focus faster due to having a different type or method of focusing than a cheaper lens.

[selmerdave]

Keller, image quality is not the only factor in the price of a lens. There are not many lenses that will beat in terms of image quality the standard 50mm/f1.8 from the major manufacturers, and those are not pricey lenses. With the higher prices you pay for certain specific capabilites that a given lens has, some of which involve considerable comlexity of manufacture. So obviously you don't spend >$1k on a 200mm/f2.0 unless you NEED specifically a long telephoto with that big an aperature. Shooting at f8 there is likely little difference from say a 200mm/f4 (MUCH less $$$), and in fact many times the smaller maximum aperature lens is superior due to its simpler construction. But there are shots you could take with a 200/2 that you could never take with a 50/1.8.

Dave