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02. Why Some Lenses Are Expensive.

So, yes, I got that new Canon 7D for an early Christmas present.  And yes, I do love it!  My Santa, who is awesome and happens to be very handsome too, also gave me this fabulous 24-70 f/2.8 that so many of you recommended very highly!

canon 24-70

And here is the kit lens that came with the camera – a Canon 18-135mm f/3.5-5.6 IS (Image Stabilization).  Would you like to buy it from me? I’m selling it for $325 including shipping, which is nearly $100 less than Amazon’s list price and $125 less than B&H.  Read through this comparison, and if you’re interested, send me an email at erin @ TexasChicksBlogsAndPics . com.

canon 18-135

Why is the 24-70 was recommended so highly over the 18-135?  Both good lenses, but there are differences.

  • Weight – At 2.1 pounds, the 24-70 is over twice as heavy as the 18-135 (1 pound).  This isn’t a big deal to me (yet), but I haven’t taken the camera on vacation or for a long day at the zoo.
  • Speed – The 24-70 is a perfect example of what people mean by a “fast lens“.   Because the maximum aperture size is bigger (a 2.8 is bigger than a 3.5), the camera lets in more light.  Bringing in more light through the aperture means you need a shorter shutter speed for good exposure (the shutter is open to let in light for a shorter time.)  Shorter shutter speeds mean less time for the camera to move or your hand to shake while the pic is being recorded.  Less movement means sharper photos.  So, a faster lens is a good thing.  Phew. Did everyone get that?  Does it remind you of those crazy proofs we used to have to do in geometry?
  • Variable vs. constant aperture – No only is the maximum aperture different, but the 18-135 can only use the maximum aperture at shorter focal lengths.  So, if the camera is zoomed in to 70mm, the maximum aperture is only f/5.6.  At 18mm zoom, the maximum aperture is 3.5.
  • Amount of Zoom – obviously, the 28-135 zooms almost twice as far as the 24-70.
  • Wide Open Focus – ok, we’ve all heard that a lens is most sharp a stop or two under maximum aperture.  For the 24-70, that would mean an aperture of 5.6, and for the 18-135, that would mean an aperture of 5.6 – 8.  The left side of this image is the 24-70 at f/2.8, and on the right is the other lens at f/4.5 which is its maximum aperture at a 35mm zoom.

Wide Open ComparisonI took another shot to see if the results would be quite so drastic.

shot 3 widest apYou can definitely see a difference.  Not that my comparison is at all scientific. . . .  I did use a tripod and a remote.

  • Image Stabilizer – the 24-70 doesn’t have it.  This feature is great for improving focus in hand held photography, especially in lower light situations.
  • Price (oh yeah, the biggie.) – the 24-70 is almost $1300.  The 18-135 is $400.  (Unless you buy mine! 🙂 )

So, is it worth it?  To me, yes.  I don’t mind the weight a bit and I love the flexibility that large apertures give me.  Having shot with variable aperture for so long, I really like the constant aperture on the 24-70.  However, the 18-135 is a great deal for the price, especially considering the Image Stabilization.  And if you need more zoom, the 18-135 might make more sense.  Plus, I think weighing 50% less is a good thing.

By the way, here’s something different abount the 24-70.  It zooms in reverse.  The lens is longer at 24mm than it is at 70.  (Don’t let this scare you if you get this lens.  I was beginning to question everything I learned about photography over the past couple of years when I first noticed it.)

02. Why Some Lenses Are Expensive. was last modified: June 21st, 2015 by Erin Peloquin


  1. Dani B
    Posted on December 9, 2009 at 12:01 am

    Thank you!! I have a Sony Alpha camera and I bought a lens that’s like, 18-300, or something goofy like that. I can’t carry around extra lenses so I bought one that gave me the widest variety. Yeah, weight is an issue since the camera hangs like…well…it hangs weird. But I didn’t realize the benefits to having a lens like the 24-70. I doubt I would spend $1300 for another lens, but I wouldn’t put it past me knowing that I have the knowledge you gave me. I just might shop for something better now. Thanks again!!

  2. Lori@Not Always Charming Says :
    Posted on December 9, 2009 at 6:51 am

    Curse you Canon…why can’t everyone own a Nikon? I REALLY want this lens!
    .-= Lori@Not Always Charming´s last blog ..Thoughts To Ponder =-.

  3. wayoutnumbered Says :
    Posted on December 9, 2009 at 5:21 pm

    What a great comparison and useful information. I’ve been reading so much lately regarding lenses and they really should be researched just as much as the camera you’re attaching it to. Have fun with your new $1300 TOY!
    .-= wayoutnumbered´s last blog ..Anatomy of…Brown Haired Girl =-.

  4. Michele
    Posted on December 10, 2009 at 2:30 pm

    Congrats!! What a wonderful EARLY Christmas present! So exciting. I am not a Canon user but I do have the equivalent to 24-70. I’ve been using the Tamron 28-75mm f2.8, it’s been quite the lens for me. The cost is much less than the Canon but the images are still quite sharp. My other favorite is the nifty-fifty, Nikon 50mm 1.4, can’t say enough about this lens. LOVE IT!! On my wish list now is the 85mm 1.4, not within my budget right now since I just got a n ew camera too but someday!! Enjoy your new toy.

    • admin
      Posted on December 10, 2009 at 2:34 pm

      Thanks Michele! I need to learn more about the Tamron and Sigma lenses. It sounds like you can find some great buys from their products.

  5. Tammy Heavner Says :
    Posted on December 16, 2009 at 2:18 pm

    I would love to have the 18-135 as a walk around lens. hmmm… I need to talk to my Santa about this! 🙂
    I have a Canon 17-40mm L f/4. I must say – if you’re a canon user and you can get yourself and “L” series lens, I highly recommend it! The 24-70 is an “L” series. I know you’ll just love it! The “L”‘s are identified by the red strip around them. Although they do cost more, they are well worth the price. They feel really good in your hands. They are slightly heavier, but I would rather describe it as being “solid”, the zoom is smooth has butter, the glass is perfect and when you click that shutter button, it’s a quiet, barely noticeable solid “click”. If this is your first “L” series, I bet it won’t be your last!
    Congrats on the new toy. I’d love to have the 7D someday.
    .-= Tammy Heavner´s last blog ..Welcome to the World Lil’ Ms. Jayden! =-.

  6. Sweet7D
    Posted on March 23, 2012 at 10:01 pm

    I received the Canon 7D for my birthday last November. The autofocus on the kit lens (28-135) just quit…(yippee!). I am a beginner photographer and I wanted to learn all that I can with this kit lens, before making another purchase. Now, I must get a different lens and am a bit confused.
    Should I get the 50 mm (1.2); the 85 mm; or a zoom lens (24-70)???
    Please Help!!

    • Erin Says :
      Posted on March 24, 2012 at 8:41 pm

      Did you take the lens to the camera shop to make sure it’s broken? Did it get dropped? Make sure the auto focus switch is pushed tight where it’s supposed to be.

      • Sweet7D
        Posted on March 25, 2012 at 10:23 pm

        Thank you. Just to update…no, the lens was never dropped. The auto focus switch was pushed tight, in the correct position. I took it back to Best Buy Geek Squad, and they decided to replace the camera and the lens. Even though it is not my first choice for a lens…it was the best option for what they were offering to me, as the replacement. I decided to also order a 50mm (f/1.4) in addition.
        BTW, I LOVE your blog!! You have a lot of great info!! Thanks for all you do!

        • Erin Says :
          Posted on March 26, 2012 at 12:17 pm

          Aww, thanks so much. And glad to hear that Best Buy took care of you. And you will love that 50!

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