Rumors of a compact 25mm (50mm equivalent angle of view) lens for Olympus Digital have been circulating in the DPReview forums. I don't know whether there is any reason to believe them other than the fact that this is what I've been wanting ever since buying the "remarkably small" E-410. The 14-42 zoom is very good, but my preference is to shoot primes. A 17.5, 20, or 25mm compact f/2 ZD lens would make my PMA!

Update - More on this rumor can be found here.

"There's a special pleasure in shooting with primes. When you're restricted to one focal length, you can learn to see in it: visualize the picture even before putting the camera to your eye. I'm sure that with experience and talent this works for zooms too; I've just never gotten that far." -Petteri Sulonen

In still photography, a prime lens is a lens with a fixed focal length. A zoom lens, on the other hand, has a variable focal length. Zoom lenses, due to their greater versatility, have largely supplanted prime lenses. However, with the ever increasing affordability and thus popularity of DSLR photography, many of us who previously shot with fixed lens cameras now have the option of trying different types of interchangeable lenses. Amongst these, prime lenses offer a number of clear advantages.

1) They are lighter and more compact.
2) They often have simple designs, which are optically less compromising than zoom lenses. Modern zooms are very, very good. However, the greater the zoom range (ie, 4x), the more compromise is typically involved. For example, the wonderful Canon EF 24-105mm f/4L IS USM, which costs about $900, has a fair amount of barrel distortion at 24mm; whereas the EF 24mm f/2.8 prime lens, which costs about $200, has none.
3) More often than not, inexpensive primes offer better image quality than inexpensive zooms.
4) They are usually faster (greater maximum aperture) than zoom lenses of similar cost.

In addition to these quantifiable qualities, primes offer an additional advantage which is much less clear. As Petteri mentioned, there is a "special pleasure" in shooting them. With a prime, a given focal length takes on the charming character of familiarity. A prime can also encourage one to see in a certain way. For example, when I go out with the versatile 24-105mm zoom lens, which covers a focal range from ultra-wide to moderate telephoto, I have a tendency to stay further away from my subject and telephoto my way in. The effect is that I am less interactive, my perspective renders subjects more flat, and I end up including less environment in my candid photos of people. Each of these three factors has a negative influence on my shooting outcomes, and together their negative effects are additive if not synergistic. Now many zoom lens users would be quick to point out that not a single one of those effects is due to any inherent weakness of my zoom, and they would be correct. After all, if I mentally tape my zoom at 28mm, then it effectively becomes a 28mm f/4 prime, and not a bad one at that. However, my mind is weak, and I am guessing that I am not the only one. Furthermore, shooting with primes has definitely affected the way I use my zooms. These days, having learned from a couple of my prime lenses, I make better use of my feet, spend far less time on the telephoto end of my zooms, and take in more of the big picture. Even so, I suspect it will be many years before I progress to the point where prime lenses no longer push me to see better.

Amongst the more objective advantages of shooting with primes, the size and weight advantage is the most significant one from my standpoint. Today I visited the Baltimore Inner Harbor as well as Fells Point with my two boys, Oliver and Philip, aged four and two. For nearly half of my photos today, I was either carrying Philip in my left arm or holding his hand. There is simply no way I could have managed with a big heavy zoom like the 24-70L, and the smaller 24-105L would have been pushing it. Managing the 5D with a 28mm f/2.8 prime attached was a genuine pleasure. It would have been no problem to throw a 50mm prime in my jacket pocket had I wanted the security of being able to change focal lengths. However, I found that once I was in the 28mm mindset, I didn't even think of changing lenses.

Over in the DPR Canon Lens Forum, two common discussion threads are "Which one lens should I buy for my DSLR?" and "I'm leaving Canon for Nikon because Canon doesn't have an 18-200mm lens." The market dominance of zooms over primes has been firmly established, and I'd be the first to admit that prime lenses aren't for everyone. However, I would encourage any DSLR user to at least try taking pictures with a prime.

Right now, 28mm is my favorite focal length. If you are a zoom user, you might not have a favorite focal length. Maybe you think all the focal lengths are special, or perhaps none of them. However, if you give a couple inexpensive prime lenses a chance, I'll bet that before long you'll have a favorite focal length too.

I've been thinking a lot recently about buying a new lens for street shooting with the 5D. The 24-105mm f/4L is incredibly versatile but makes for a heavy combination with the 5D at 3.5 lbs combined (2lbs for the 5D and 1.5 lbs for the 24-105L). It's also a somewhat imposing lens to have pointed in one's direction. I enjoy using the 5D with the 50mm f1.4 but want something wider. I've now settled on one of the oldest and possibly the most forgotten lens in the EF lineup, the 28mm f/2.8. Surprisingly, there are some reports that this lens is a better performer on full frame than on crop bodies (excepting light falloff of course), which would go a ways towards explaining why it has been largely forgotten in this digital age.

Why the EF 28mm f/2.8?
- At 1.7" long and 0.41 lbs, this lens is tiny.
- At an average used price of around $120, it's cheap. No Canon autofocus lens with a metal mount is cheaper.
- 28mm is an awesome focal length.
- It has a distance scale, great for setting up to take quick shots from the hip.
- Markus Hartel uses one.

Click here for an interesting comparison of 13 lenses at 28mm, tested on a Canon 5D. I think the EF 28mm f/2.8 does pretty well.

That's all for now. More when I get the lens!