Canon 55-250mm f/4-5.6 IS - In Depth
18 April, 2008
As promised, I have quite a bit to say about the rather hard to define Canon 55-250mm f/4-5.6 IS lens that I recently got.
I say “hard to define” because the lens is quite a mixed bag - there are features that are great about it, and features that really show the “budget” portion of this rather inexpensive lens.
Let’s start with the basics of build quality and mechanics. The 55-250mm IS is an EF-S lens designed for our crop-body cameras, and it shows that Canon has let the budget drop a bit on these lenses. After all, they’re assumed to be for more amateur photogs who are not going to utterly abuse their equipment - so don’t go expecting a metal body and L-quality glass for the meager price of $279 USD.
Indeed, the 55-250mm reeks of budget in this department - even the mount where lens meets camera is made of plastic, which doesn’t give the sense of quality or security that higher grade lenses exude. However, the lens does work solidly - when it extends during zoom or focus, there’s no wiggle in the lens and it doesn’t seem to “creep.”
Autofocus on the lens is slow - even in decent light, it takes a couple seconds of seeking to find your target, and in AI Servo mode (the mode where the focus “moves” with your subject) the focus will sometimes lag and will prevent you from snapping a picture while it attempts to catch up. I would honestly say that this is the worst problem the lens suffers from, but it is not insignificant. If you’ve got the time to wait for it, it’s not a big deal - but don’t expect to be getting flying birds or catching a lot of moving-target snaps with this lens.
Another issue on the Canon 55-250mm f/4-5.6 IS is the bokeh - unfortunately, the lens generates some rather harsh blur. I can’t put my finger on exactly why, but I find it to be distracting and a touch offputting, especially in hard light. It’s not always bad, as you can see by the flower shot at the beginning of this post, but it’s a little rougher in one of the shots below. Expect to retouch the blur a bit with photoshop if you want a nice and creamy blend.
Now that I’m done taking shots at it, let’s talk about what the lens does right, which is actually quite a lot. It covers a wide focal range for a tele lens, but aside from the bokeh its optical quality is superb. Chromatic aberrations are pretty much zilch, distortion is damn near nonexistent (certainly not relevant to field use) and there’s no softness across the whole image, even out to the extreme corners.
On top of that, despite the fact that it’s a bit harsh bokeh in bright light, the lens delivers nice and creamy bokeh when you can control your lighting conditions. It makes me wonder how it would fare as a studio lens, where flash could make the narrow max aperture irrelevant and lighting could be properly tweaked to suit it. I may have to send it down to my friend Eric to find out, as studio work is not my strong suit.
The IS promised by Canon assures four full stops of shutter speed, meaning that hand-shake can become essentially a non-issue. However, as mentioned in a previous post, that’s not going to help you when the subject is moving. With the narrow max aperture and the long length, you should expect to be cranking the ISO up to 200 - 400 to keep your subject sharp in anything but bright daylight. I was not able to recreate the full four stops in testing, but I did get a solid three out of it - not bad at all for a lens south of the $300 border.
Overall, I feel like the old adage rings true for this lens - you get what you pay for. Is it a great alternative for those who are shooting in the wild and drooling over the 70-200mm f/4 or f/2.8 IS? In a word, no. But that’s just it - it’s not purporting to be that lens.
What it is is a great value for people who need a lens that covers that focal range without having to be great at it. It’s a terrific buy if you normally shoot wide but just need a tele for those one-off shots. I think that in this respect, the lens represents a great value for the money - it does just what it says on the tin and it does it well.
With that in mind, I’d give it a wholehearted recommendation to the right people…landscape-oriented amateurs will delight in this as a functional and comfortable safety net to catch something that they can’t get too close to. However, people who look to shoot moving wildlife or in lower light will find that they’re better suited saving their pennies for that L-series glass. It’ll sting, but it’s money well spent.
Before I leave you to it, I figured I’d post a couple more shots of the lens in action:
Topics: Equipment, Photo Shoot | No Comments »
The Tamron 17-50mm f/2.8 - In Depth
17 April, 2008
So, I’m a bit late with my post this week - there’s perfectly good reason for that, I think. April 15th is my day of unending torture due to the wonders of the Infernal Revenue Service. But, it’s done and I’ve moved on.
I promised a better look at my two lens acquisitions this week, and so I’m starting with what I think is the better of the two - the Tamron 17-50mm f/2.8.
To be perfectly honest, I was nervous about spending a bit over $400 on a third-party lens, even if it was “free” money (I had earned about $600 in Amazon Gift Certificates from my bank). However, everywhere that I looked on the web turned out to be a favorable opinion of the lens.
Now I see why.
Let’s start with the build quality. The lens feels heavy for its size, and you’ll definitely find yourself supporting the camera correctly (by the lens) if you hadn’t done so while using the kit lens. It has a metal mount and a sturdy feel to it - it’s not like holding weatherproofed L-series lenses, but it will definitely stand up to the knocks and bumps that any amateur is likely to throw at it.
Also on the mechanical quality, one needs to be aware that this is not a USM lens - autofocus is a touch on the noisy side. However, this is not too obtrusive and it’s not really any louder than other non-USM lenses. In addition, the focus ring on the lens is not decoupled from the AF motor, so the ring moves in AF mode. The lens does not support Full-time Manual focusing, which is a pity, but a very minor complaint - flip the switch from AF to MF and get on with your life.
Even with these minor niggles, the lens is superb. Optical quality is spot on, with an incredibly crisp center and very nice corners as well. Surprisingly, despite the lens being made only for crop-body cameras, vignetting is pretty well non-existent. And chromatic aberrations? Nada. You will see a very tiny amount at 17mm @ f/2.8, but I feel this would be irrelevant in actual field usage.
There is one thing worth noting on the optical quality, and that’s a bit of a “bent” focal plane. I’ll try to take a picture that illustrates this clearly, but the field of focus is actually curved. This is natural for any lens, but there are tricks to work around it in the lens mechanic. On my copy, this is not too apparent, but you may notice that at low apertures (f/2.8, f/4) your subject is in focus in the center but something that’s actually behind your subject is in focus at the edges. Expect it to happen most when you’re close to your subject with a very shallow Depth of Field. This phenomenon disappears at about f/4.5 and above or when focused out far distances.
As odd as it is, it’s actually a godsend when shooting such wide apertures for portrait work and the like. Most lenses at f/2.8 can focus on the nose and eyes, for example, but the ear will then be out of focus. This curved focal plane fixes that problem, allowing the focus to “wrap around” the subject. So, just because it does something you wouldn’t expect doesn’t mean it does something bad - it’s just a little quirk to get used to.
So, is the lens worth its salt? In a couple words, “Hell yes.” At the price this lens costs, it’s an affordable trade for the kit lens. The build quality is great for the cost (far better than other Canon zooms in this price bracket) and the optical quality is superb. The extremely wide aperture makes for a very, very versatile lens that you’ll find sits on your camera a majority of the time. All of this for under $450 will leave you wondering why every lens can’t offer this much bang for the buck.
I’ve got a couple shots of the lens in action that I’m uploading right now, so you can see it in a few of its more useful moments - portraiture and landscape. To top that off, you can expect a full write-up on Friday about the Canon 55-250IS lens. Who said good things don’t come free?
Topics: Equipment, Photo Shoot | No Comments »
« Previous Entries