The Life of a Lens

Yesterday we looked at things to consider when getting a new camera body…while the idea is all well and good, lenses are another story, and since we are likely to invest more in glass than in cameras (Have you seen the costs of some of the really good glass lately?), the life of a lens is something worth considering.

In all things technology-related, there is a principle called Moore’s Law which states that technology will advance at a rate of re-doubling roughly every two years.  While this principle was developed primarily for computers, we can draw similar analogies for digital photography too, with the sensor being analogous to the transistor.  The rate of increase has not quite been on par with re-doubling every 2 years, but the increases can be noted pretty impressively going from a mere 4 in 2001 to a current rate of  21 MP per frame for DSLR cameras (I am only looking at the Canon line-up here:

  • Canon 1Ds Mark III = 21MP (2007), Retail
  • Canon 1Ds Mark II = 16 MP (2004)
  • Canon 1Ds = 11MP (2002)
  • Canon 1D = 4 (2001)

Lenses aren’t like that though – focal lengths don’t change that much.  Instead, technology has allowed lenses to become faster at the longer end of the given focal lengths.  We’ve also seen the introduction of image-stabilization technologies.  The addition of new technologies in lenses does not necessarily deprecate previous generations – it merely antiquates them!  This means your lens may not have the bells and whistles of future generations, but it should work indefinitely if treated properly.

Keep in mind though that there is a distinction between full frame and crop sensor cameras here though, because Canon has two lens lines, the EF line and the EF-S line.  The EF-S line is intended for the crop sensor cameras and cannot be used on the full frame mounts – if you try to use an EF-S lens on a full frame body, the mirror could slap down and shatter the back element of the glass, so avoid this scenario if at all possible!  (There are some converters on the market that will extend the gap between the mirror and the element to avoid this, but I’ve not used them.)

Lenses are also different from camera bodies because there are no moving parts that can fail.  Well, that’s not entirely true because zooms do have moving parts when you rotate the lens, and these can fail. * However, because the lens is always a closed item, the susceptibility of a lens to parts failure is not as high as it is for camera components.  Shutters, for instance, have a certain lifespan for which they are rated, (usually somewhere between 50,000-150,000 actuations).  Lenses don’t fail after a certain number of focal adjustments (assuming you are handling the lens correctly), and in the case of fixed focal length lenses (primes), this is even less the case.

So, a lens can literally last for as long as the vendor makes a body that will accept the mounting mechanism, and in the case of most vendors, I don’t see that changing any time soon.  I’ve had my kit lens from Canon when I got my first Rebel XT back in 2004 and it still works great on my 40D – it may not be in the lineup anymore (neither is my 40D either, but I digress…), but any EOS body will accept this lens and the image quality has not deteriorated at all over time!  Lenses can last forever!

How long have you kept your lenses?  Do you have any “go-to” lenses in your bag that you anticipate will always be there?  Let me know your favorites!

On a blog administrative note, don’t forget that there’s still a little time left in the Flickr Giveaway thread for December, so if you have any shots (the holidays are good times to capture those “Giving” themed photos), make sure to get one in for a chance to win that $400= prize package!  Happy Shooting and we’ll see you back here again tomorrow!

*ETA:  Special thanks to Marco for pointing out in the comments that there are quite a few moving parts in even fixed focal length lenses.  In addition to the focusing ring, there is also the diaphragm that moves which closes down the aperture to the correct setting for every actuation of the shutter, so there are moving parts in any lens, including fixed focal lengths.)