Why are good lenses 'better'?

Discussion in 'Photography Equipment & Products' started by Illah, Oct 13, 2006.

  1. Illah

    Illah TPF Noob!

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    Sorry for so many posts, but I'm planning to purchase my first high-end lens (moving up from the 18-55 DX kit lens) and now that I'm at the point where I'm getting ready to plunk down $500, this question hit me...

    Why is a good lens so much better?

    I mean sure, sharpness, wider aperture, etc. But what is that it? I was just playing around this morning with the kit lens and took what look to be some quality pics on the camera LCD (will verify at home on the big screen) so I started thinking...what am I really buying this new lens for? Is it $500 just to get f2.8 throughout?

    Thanks,

    --Illah

    P.S. Yes I understand a good photographer will take good pics with a crap camera while equipment won't make a bad photographer any better - I don't expect a new lens to suddenly make 'better' pictures ;)
     
  2. Alex_B

    Alex_B No longer a newbie, moving up!

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    Hey, that is already quite a lot of advantage :).. really, I mean it!

    wider aperture also means brighter image in the viewfinder, often also faster autofocus. Oh yes, the AF in the lense might be better as well. It might be built more sturdy. And there might be less distortion at the far and near end of the zoom.

    - sharpness is an overall advantage.

    - wider aperture can help you great deal in available light photography, and also it gives you so much more creative possibilities (limited depth of field)

    - less distortion will be very important when you go for architecture shots, in particular at the wide angle end of your lens.

    - hmm, what of further quality issues? abberations, like chromatic abberation might be less when you go for a more expensive lens.

    Of course the dependence of all these improvements is not linear with the money you invest ... if you go from a 100$ lens to a 500$ lens, the improvement might be huge, but if you go from 500$ to 1000$ it might be marginal. I say "might" because it always depends which lenses you compare. And there are some fairly good ones out there which do not cost that much as I understand.
     
  3. Big Mike

    Big Mike I am Big, I am Mike Staff Member Supporting Member

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    There are a lot of things that seem to be more important now, in the digital era...that were not so important when everybody shot film. It's so much easier to see and to pick out the deficiencies in a digital image...and it gets easier to talk about on the Internet every day too.

    Are there things that your current lens does, that you don't like? Are there things that you can't do, that you wish you could, with your current lens?

    There are certainly advantages to using 'better' lenses, as mentioned...but unless you really need them...that's a lot of money to spend.

    I always like to suggest a cheap prime lens like a 50mm F1.8. It's a great supplement to a kit lens. It's fast at F1.8, it will have great optical performance...and best of all...it's cheap.

    Hey, if you need a high end lens, the go for it. Think of these things as tools. A carpenter will usually spend more money and get good quality tools. Does that mean he can build a better house...not really. But in the end, he may get the job done quicker, easier and it may cost less in the long run.
     
  4. W.Smith

    W.Smith TPF Noob!

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    Relatively 'cheap' lenses generally have (much) more http://en.wikipedia.org/wiki/optical aberrations (<– click!) than more expensive lenses do.

    As a rule of thumb: more expensive lenses result in much better image quality.

    So, basically: you get what you pay for . . . !
     
  5. Illah

    Illah TPF Noob!

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    Yeah, the 2.8 is a major plus. My current lens has a max 5.6 at or near the end of the zoom range, so that's two full stops I'd be gaining (and at least a stop throughout the rest of the range). Since I like to shoot a lot of low light that's a major plus. And yeah, I do notice the 'bubble' effect at 18mm with the kit lens, which isn't always terribly bad, but on some shots it shows.

    I never really noticed too many other problems with the current lens, and other than the aperture limitations I'm actually pretty happy with it (the barrel distortion issue at 18mm only noticably effects a small percentage of my shots). I guess that's where my doubts are coming from :)

    If the new lens was $200 this post wouldn't even exist, but at $500 I'm a little more cautious!

    --Illah
     
  6. Don Simon

    Don Simon TPF Noob!

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    If low light shooting (especially handheld) is your thing then I'd go with Mike's suggestion of a fast fixed lens. A 50mm prime will cost a lot less than the zoom and if you get one with a maximum aperture of f1.8 or even f1.4 there are two major advantages. First of all the lens is useable in lower available light; you'll be able to take shots handheld that would be very tricky with an f2.8 zoom. Secondly when you stop that prime lens down to f2.8 it'll probably be noticeably sharper than the f2.8 zoom lens at its maximum aperture.
     
  7. Alex_B

    Alex_B No longer a newbie, moving up!

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    I agree that the 50mm f/1.4 prime is a reallly good lens :) I love it!
     
  8. fmw

    fmw No longer a newbie, moving up!

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    As with most products, there is a law of diminishing returns with photographic lenses. By that I mean that small, incremental improvements in performance carry differences in price that are out of proportion to those improvements.

    As I've said, lens design is a collection of compromises and corrections. The better and more expensive designs provide fewer compromises. Making fast lenses creates the need for even more compromises and a quantum leap in cost. "Better" lenses cost way more than lesser ones for only small improvements.

    The most important difference between my 17-55 zoom and your 18-55 is the maximum aperture - 2 f stops at the long end of the zoom range and 1 f stop at the short end. That provides me with more flexibility in terms of exposure and depth of field. To me that is a big deal. To you it may not be.

    Let me give you a more extreme example. In my pro days I used to own the very high performance AF 300mm f2.8 Nikkor ED telephoto which cost thousands of dollars. I had a friend who owned the f4 model which cost perhaps a quarter of mine. My lens was only a single stop faster and very noticeably larger and heavier. Yet he would borrow mine quite often to do sports photography. Why? That single f stop was a big deal to him. He was willing to lug my big lens around and take the financial responsibility for a sizeably expensive lens when he had a wonderful lens that was just a single stop slower. It is a matter of needs and priorities.

    The "better" lenses are more ruggedly built and will put up with a higher duty cycle and more abuse than cheaper ones. That is extremely important to a pro who values reliability above all else in camera equipment but it may not be so important to you.

    The other performance factors like corner sharpness or light fall off or contrast are slightly better on my lens than yours but only slightly better. It wouldn't make any sense to me to pay for the upgrade to get those minor benefits. The maximum aperture and reliability are the big ones.

    So let's take a look at the option suggested above of buying a fast prime lens or maybe two. If you were to add, say, an AF 35mm f2 Nikkor (normal lens on your camera) and a 50mm f1.4 (short telephoto on your camera) you would have all but the wide angle portion of the zoom range covered with lenses that are even faster than my zoom and are lighter to carry combined than my zoom and would even outperfrom my f2.8 zoom noticeaby - particularly in terms of contrast. If you bought them used, they would easily cost half the price of my zoom. You would still have your zoom for use in the wide angle range where your lens is fastest. It makes some sense, doesn't it? If you ask me if I regret having sold my 35mm f2 and my 50mm f1.4 when I went digital, the answer is yes.

    More importantly, it is not equipment that makes a great photograph. It is a great photographer. The equipment is just a tool. As a novice it is easy to get embroiled in the details of equipment but not terribly important. It is more important to go use what you have and learn and grow in your image making. In time you will learn what is and what is not important to you in terms of equipment and why. Then you can change equipment if you want to and enhance your photography instead of just getting new stuff.

    I hope that all makes sense.
     
  9. LWW

    LWW TPF Noob!

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    Why would you pay more for a Corvette than a Cobalt?

    Same maker.

    Does the same thing.

    The principles are the same in the comparisons.

    LWW
     

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