Lens Tech Specs
Focal Length & Maximum Aperture:
|17 - 40mm; f/4|
| Lens Construction:
||12 elements in 9 groups|
|Diagonal Angle of View:||104° - 57° 30'|
|Focus Adjustment:||Inner focusing system with USM|
|Closest Focusing Distance:||0.28m / 0.9 ft.|
|Zoom System:||Rotating type fully inclosed, non-extending zoom.|
|Max. Diameter x Length, Weight||3.3" x 3.8", 1.1 lb. / 83.5 x 96.8mm, 500g|
The Canon EF 17-40mm f/4L USM lens was released in 2003 and it has become one of the only semi-inexpensive Canon L-Series lenses in the retail world. The Canon EF 17-40mm f/4L USM lens offers high quality images at a slightly above mid-range price.
The lens is an EF mount which means you can use it on 35mm bodies which have smaller sensors (like the Canon 30D and Canon 20D, XTi) as well as full frame sensor 35mm bodies (like the Canon 5D and Canon 1Ds Mark II, III). The 17-40mm lens is fairly wide, but on most common digital bodies like the Canon 350D, 20D and 30D bearing the 1.6x crop this lens is more of a 27-64mm which is still very wide for a 1.6x crop body and definitely a must for tight quarters.
The Canon EF 17-40mm f/4L USM lens can easily be compared to the Canon EF 16-35mm f/2.8L lens, which is a full stop faster than this lens and about double the price. I guess at double the price you able to get twice as much light, which for some that is an absolute must.
The Canon 17-40mm f/4L lens weighs in at a very reasonable 475g and is slightly smaller than the Canon 16-35mm f/2.8L lens. The 17-40mm is also sealed for harsh conditions, so you don’t have to worry too much about the weather making it’s way inside. The build quality is superb, which is to be expected, as it is a Canon L-Series lens. The zoom and controls are just about as smooth as can be, in-fact it is almost perfect.
The lens is also equipped with full-time manual focusing, which allows you to focus manually even when the auto focus mode is turned on. You simply set the camera to ONE SHOT AF mode and then press the shutter button down halfway. While you have the shutter button down halfway you may turn the focus ring to focus manually. This function is standard on all the Canon L-series lenses, which prevents the user from stripping his focus rings while trying to focus manually in the AF (auto focus) mode.
The subject distance scale comes standard on the Canon EF 17-40mm f/4L USM lens, which I wish was present on every Canon lens. This allows you to gauge (to a degree) how close you are to the subject you are shooting.
You might consider purchasing a better lens hood for the Canon 17-40 though The lens hood that it comes standard with is a pedal shaped hood, specifically the EW-83E and it is often times not sufficient for certain situations. You might look into purchasing the Canon EW-83D, which will fit the Canon 17-40mm lens just fine and give you a bit more cover from the unwanted light.
The lens comes standard with the powerful ring type USM (Ultrasonic Motor) drive which enables you to have lightning fast focusing, with a silent motor so you don’t scare away the wildlife or in this case the landscapes (which doesn’t make any sense). It also helps to be able to focus quickly and accurately when you don’t think conditions will permit.
Canon 16-35mm f/2.8L versus the Canon 17-40mm f/4L
I suppose you want to know how the Canon EF 17-40mm f/4L USM lens compares to the Canon EF 16-35mm f/2.8L USM lens as far as image quality and sharpness are concerned. The 17-40mm lens image sharpness is exactly the same as its competitors the 16-35mm lens. In-fact I found that for the most part the 17-40mm won out over the 16-35mm, but that was before they came out with version II, so we will see how good the improvements actually were. The only hugely noticeable difference between the Canon 17-40mm and the Canon 16-35mm is that the 16-35mm lets in twice as much light for twice the price. The level of distortion on both lenses on the super wide could have been a bit better, but then again you are not going to get too much of an improvement by going prime in my opinion. All in all the Canon EF 17-40mm f/4L USM lens is an amazing lens for a relatively affordable price, and with the shots I take I never leave home without it. I think you will be more than happy with this addition to your lens collection.
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