Monday, February 7, 2011

Canon Lenses Chat - Part 3: Prime Lenses

If you are a regular on this blog then by now you should know that Mic sports a Nikon system, and we got to know each other because of some of my comments on his posts then came a day when he made me a contributor to this blog, we agreed that I should address the Canon half (red team) of the blog while he will keep you posted about the Nikon half (yellow team).

So, this is the third and final part in a series of posts where I get to ramble about some of Canon's consumer lenses, the first part was about standard zoom lenses, the second part was about telephoto zoom lenses and in this part I will talk about prime lenses.

Why a prime lens?

If you check Canon's current EF lineup  you will find that they have 39 fixed focal length lenses (in other words, prime lenses), they cover everything from extremely wide angles (fish-eyes and tilt-shifts) to extremely long focal lengths, so why are there more fixed lenses than zoom lenses? Not to mention that other big names like Carl Zeiss and Leica produces prime lenses almost exclusively. Coming from a point and shoot background myself, I though that zoom lenses are the norm and that having a fixed focal length would be a real pain in the bum, so again, what is the whole fuss behind the primes? I can tell you about some points:
  • Prime lenses usually have a simpler design than a zoom lens, this enables the manufacturers to make these lenses with excellent optical qualities (extreme sharpness, low chromatic aberrations, etc...)
  • Since these are fixed lenses with no zoom, they can be quite small and light compared to zoom lenses, my Canon EF 50mm f/1.8 II pictured at the top of the article weighs a mere 114 grams. Of course there are heavy primes as well, but they are usually smaller and lighter than zooms, especially the zooms with wide apertures.
  • Now we get to the most important attribute of prime lenses, wide aperture. One of the main reasons non-photographers buy DSLR cameras is the shallow DOF look where the main point of interest in the photo is in focus and everything else is blurred and out of focus, this is the most distinctive feature between a DSLR (or a large sensor) camera and a point and shoot (or a mobile phone) camera. Sometimes the shallow DOF gives a desirable look to the picture. To achieve this effect (i.e. decrease the DOF) you can do it by using any of the following methods or a combination of them: large sensor, wide aperture, long focal length, close subject distance. For more information check this incredibly useful page:
  • Wide apertures are the pièce de résistance of the prime lenses. The brightest zoom lenses usually have apertures of f/2.8 (with the exception of a couple of Olympus f/2 zooms) while the slowest prime lenses are usually f/2.8 (except for extreme telephoto primes). For example you can have an 85mm f/1.2 lens which is 2.5 stops brighter that an already bright 85mm f/2.8, this allows for shooting in very dim conditions with a reasonable shutter speed and low ISO. Just for the record I want to say that there are some exotic f/0.95 and f/1.0 lenses.
  • The downside of these wide apertures is the resulting shallow depth of field which can be in the order of centimeters or even millimeters (think of an eye pupil in focus while the lashes are out of focus), this shallow DoF can be desirable sometimes and not that desirable at other times when you are trying to shoot a group of your friends for example and want everyone in focus.
  • One more benefit of wide apertures is the use of bounce flash, your flash will emit much less power when you use a wider aperture which will enable you to bounce in extreme situations and have fast recycle times.
  • The idea behind the wide apertures of the prime lenses is that they have a fixed focal length, so even if they use a large front element to build a fast lens it will still be much smaller and lighter than a zoom lens with the same aperture. Take the Canon EF 200mm f/2.0L IS USM for example, it costs $5700 and weighs almost 3 kilograms with the hood, can you imagine what a 70-200 f/2.0 lens would be like if it existed?
Bargain Canon Prime Lenses

Now I will not claim that I am a total lens expert or anything, I am talking from the view point of a serious amateur. When I first bought my DSLR it came with 18-55 standard kit lens and I bought the 55-250 telephoto at the same day before I went home, I knew that the ultimate Canon beginner kit included the 18-55, the 55-250 and the 50 f/1.8 lenses. This triplet gives the most value for money and covers the focal range from a reasonably wide (29mm equivalent) angle to a reasonable telephoto length of 400mm equivalent.

The Canon EF 50mm f/1.8 II is Canon's cheapest, lightest and smallest lens, yet it has a wider aperture than any Canon zoom lens and only cost me $100. Buying this lens was a no-brainer, getting an extremely sharp lens with good colors and a wide aperture for just a hundred dollars is a bargain, and since I got this lens it sat on my camera for 60% of the time, just look how sharp pictures can be from a RAW file with just the ACR default sharpening settings.

Old Timer - Click the picture to see a larger version.
 After living for a while with my ultimate beginners lens kit, I was spoiled by how sharp the 50mm was and I started using the 18-55 kit lens less and less until it was used exclusively when I needed a wider angle, so I upgraded the kit lens to the much sharper 15-85, and if you have read the previous part of the article, I have decided to keep my 55-250 for the time being. Next I started looking for an upgrade to my 50mm f/1.8, most of the f/1.4 and f/1.2 lenses are extremely expensive for an amateur like me so they were out of the question until I get either filthy rich or start gaining money from photography. However there are some exceptionally good prime lenses that cost less than $400:
  • Canon EF 50mm f/1.4 USM: same focal length as mine with a slightly faster f/1.4 aperture, a much better USM auto-focus (I was corrected by dpreview member bronxbombers, here's his quote: I wouldn't at all say that the 50mm 1.4 offers a much improved USM AF over the 50 1.8. The 50mm 1.4 has an awful clutched micro-USM that is prone to breakage, not amazingly fast and not very precise.) and a better build quality, however it's sharpness was no better than my lens at apertures beyond f/2.8 (where I always use my 50mm) and I don't see a reason to spend more money for the same focal length. There are some talks about bokeh quality as well, but that's for another article.
  • Canon EF 50mm f/2.5 Compact Macro: same focal length again, besides I already got myself the excellent EF-S 60mm f/2.8 Macro lens by saving money buying the EF-S 15-85mm instead of the EF-S 17-55mm. I will make a post about the macro later on.
  • Canon EF 85mm f/1.8 USM: an excellent lens with USM auto-focus and very nice bokeh and loved by lots of people, however in my opinion and usage scenarios the 85mm focal length is a bit odd on a crop sensor (136mm equivalent), while suitable on full frame cameras, I'm not sure if I can take this lens on its own for walk. The 50mm and the 60mm (85 and 100mm equivalent) I already have are quite long and causes me serious problems when shooting large groups, so I better save my money for something else (looking at you EF 200 f/2.8).
  • Canon EF 24mm f/2.8: now this focal length is more suitable for a crop sensor and will make a nice change from the 50mm and 60mm primes I already have, however it's optical qualities and widest aperture are inferior to the next contender in this list which is the...
  • Canon EF 35mm f/2.0: this lens has an almost optimum focal length on a crop sensor for a general walk-around lens which is 50mm on a 35mm camera, and while this lens has a 56mm equivalent angle of view; it is much wider than my 50mm and 60mm lenses. It has excellent optics and sharpness all around, it's only back-draw is the buzzy auto-focus sound (no USM), but I can live with that. One of the nice things about this lens is the close 24cm focusing distance. I am in the process of ordering one.
  • Sigma 30mm f/1.4 EX DC HSM: For $39 more than the $400 target, this lens is equipped with a fast and silent hyper-sonic motor, a wide f1/.4 aperture, a lens hood, a soft pouch and a decent build quality, this puts it in a class of it's own. This lens has many admirers and I was one of them, but I knew from lurking around the lens forums that you may have to go through several copies to find one that focuses accurately with your camera, so I created this thread in dpreview and the answers scared me away (mainly because of low light focusing issues) from any 3rd party lens since we don't have any DSLR lens dealerships in Egypt, so it's the Canon 35mm f/2 for me.
I started looking for a wide angle prime when I was with my family once and wanted to take a self portrait for us, I had the 60mm macro with me then, and I kept pushing the tripod further away until I got us all inside the frame, so that's the main reason behind my search for a cheap wide angle prime. And if you think that you can zoom in and out by moving the camera closer or farther then think again, it is not the same as using a wide angle lens in the first place as illustrated by this brilliant post on DPS.

As a final note, I will be later looking into getting both the 200mm f/2.8 prime coupled with a 2x extender which will give me a 200mm f/2.8 and a 400mm f/5.6 lens (320mm and 640mm equivalent). I will also talk in a future post about the Olympus Zuiko 50mm f/1.8 lens on my Canon. ;-) Maybe after that one I will dedicate a separate post for the 60mm macro.

Here are a few samples taken with the 50mm (don't forget it only cost $100) to see how good it is, click on the pictures to see a larger version, the EXIF data is intact in case you have any wonders.

Brownie Cake - Click to see a larger version.
100% Crop of Colorful Salad - Click to see a larger version.
Red Flower - Click to see a larger version.



    1. As soon as I used a prime lens for the first time I instantly noticed the advantages.

      I'm keeping my kit lens but every lens I get from now on will be a prime.

    2. Yes, I know exactly how you feel, however the zooms are more flexible sometimes.

      What I really like about primes is that they force you to think about composition; not just zoom to your subject and snap away.

    3. Yes as long as you have the ability to move around then not being able to change the focal length doesn't really matter.

      The physical lens size, large aperture and sharpness of photos taken with primes changed everything for me.

      But yes, I guess for others it depends on the surroundings and the subject.

    4. I have the Sigma 30 f/ 1.4 and would point to a couple of blog posts: this one, on end-of-year repair data, and This Lens is Soft (And Other Myths which describes the variability in cameras and lens more generally. The latter points out that focus problems are generally more obvious in fast lenses because their depths-of-field are so shallow, and micro-focus adjust (MFA) exists to correct these kinds of problems.

      But a lot of consumer-level cameras (including mine) don't have MFA. So if the focus is subtly off, as is often the case with very fast lenses, the lens may appear soft or mis-focused on a given camera.

      In my case, I had a slight front-focus on the 30mm, and I sent it to Sigma's Arizona service provider, C.R.I.S., to have the lens adjusted. It came back with lovely, spot-on focus.

      Anyway, the 35mm f / 2 is also attractive, and I primarily bought the Sigma because its design is much newer, and, secondarily, because of the aperture advantage.

    5. Thanks for the information, I am an avid follower of and I have read these posts.

      Unfortunately we don't have a Sigma dealer in Egypt, I love their 30mm, 50mm and 85mm f/1.4 lenses.


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