USED Canon 70-300mm F4-5.6 L IS USM Lens

I'm a scientific imaging professional and I selected this lens for a travel kit along with an EOS 6D body and an EF 24-105mm 4/L IS USM lens. This lens is physically shorter than either of the L series 70-200mm telephoto zoom lenses and thus it is easier to pack. The whole rig - camera body and two lenses - fits a padded bag the size of a small lunch box. In some ways the compactness of this lens also makes it easier to manage on the camera as well. Balance on the 6D body is very good and handling feels very natural. High quality, solid mechanical design are obvious in every detail. The fact that it resists rain, dust, and other photographer's enemies means it will be trustworthy under all reasonable conditions.Concerning handling, some reviews criticize the location of the zoom ring on this lens. I find that to be an empty criticism unless perhaps you are very set in your methods and very much in a hurry. Here is what I find using this lens: The focus ring is wide so it feels just as natural to hold either focus ring or the zoom ring (which is closer to the end glass). Holding the lens farther forward (the zoom ring) improves stability, and shot composition using the zoom is then easy to tweak. Meanwhile, the fast and very accurate ultrasonic focus motor does a great job in critical focusing. If focus isn't exactly correct you could move your hand to the focus ring and get it perfect. But doing that is typically slower than re-aiming the focus sensor and refocusing automatically before taking your shot. So think about how you approach fast-action shooting and decide for yourself whether the zoom ring needs to be in the same location for every lens. For me - I get more useful material thinking about composition, using autofocus, and taking extra shots.Optically, this lens is a gem. It is extremely crisp. Details are sharp and (with the 6D body) colors have beautiful, natural saturation. I couldn't believe the minimal lens flare when the sun is in the frame! These are sophisticated optics! Still, there are always compromises. In this lens, you get a wide zoom range (70-300) in a small overall package. What you give up is long-end maximum aperture - only f5.6. While that f5.6 is a bit of a downside, here is the nominal maximum aperture (reported by the EOS 6D body) vs. zoom range - you can decide for yourself whether the working apertures are adequate. f4.0 = 70-100mm, f4.5 = 100-160mm, f5.0 = 160-220mm, f5.6 = 220-300mm. In the shooting I have done so far, any kind of daylight and you're good. In dim conditions, you will be pushing ISO (and loosing detail) or needing a steady rest or tripod. FWIW, I find I'm rarely zoomed out into the f5.6 range, plus the image stabilization has never given me a shaky image in daylight. At long reaches I get slightly sharper images when the lens aperture is stopped down at least to f8.In summary, color rendition, contrast and sharpness are the really strong points of this lens. The fact that it is relatively small and easily packed means it can be with me whenever needed. I can hardly wait to tote this little rig on a flight to some exotic spot where the beauty of nature and people is there for the taking. Update: I have now been halfway around the world with this kit (6D body and two zoom lenses), carrying it all day/every day. You do notice some weight but it is very manageable. The trade-off is there is no substitute for the L series lens quality and the results speak for themselves. Looking at the photos people comment that the places visited look incredible! That impression starts with the technical quality of the lenses and body. [Tip from experience: I find it useful to check the AF and IS switch settings each time the lens goes on the camera because they can accidentally change during handling plus it is easy to forget that you intentionally changed them.]

Okay, so I've played around with this lens with my 60D including some at-home personal tests and I must say that this lens is an absolute excellent performer. But is it the right lens for me and is the price justified? That I can honestly say I don't know.Sharpness is excellent at all focal lengths, even the difficult 300mm long end of the zoom. I wouln't say overall its sharper than the 70-200mm F4 IS but in the same league. Contrast is excellent starting at wide aperture and the CA are well controlled which contributes to a perceived sharpness that blows your mind. The IS stabilization works much better than the one in my 15-85mm lens. I would say the 4 stops equivalent is accurate. There is a switch to go from stationary to panning IS modes.If you haven't played with a white L lens before its hard to describe the feeling you get when you shoot with one. The build quality is just superb. Everything about it makes you fall in love.This lens is the first Canon lens to feature flourene coating over the front and rear lens elements, which make it easier to clean. It is the same coating used on the AA filter over the sensor.The focus ring is behind the zoom ring (closer to the camera body) which is my preferred ideal location. This is opposite from the other 70-200 L lenses. Since this is a full-time manual focus (quick shift) lens I can hold the focus ring even while it focuses in Auto mode.Speaking of the other 70-200 L lenses, I had a very hard time deciding which one to pick. I eventually was deciding between the F4 non-IS version, the F4 IS version, and this one. All lenses show excellent sharpness so I wasn't too worried about that. The F4 non-IS looked so enticing because of the price but I've played with non-IS telephoto lens before and its difficult without stabilization. Even a fast aperture F2.8 70-200 lens, despite sharp images due to faster shutter speeds, will still have a hard time composing/framing a shot while your hand shakes. If you use the tripod a lot, I say go for the F2.8 non-IS version versus the F4 IS version. But I like to take pictures on the go, so it was the F4 IS version for me. So then, I thought..well..the 70-300 L has 100mm more reach and to get the equivalent with the 70-200 F4 I have to put a 1.4x teleconverter (actually its 280mm). To me, the added item in my camera bag and risk of more dust particles taking off the lens wasn't appealing. Besides its not a full 70-300 focal lenth, its either 70-200 or 98-280. The final kicker was that I wanted something more compact, and the 70-300 won me over.I know the F4 version is constant aperture, but when you add the 1.4x teleconverter it loses a full stop of light so essentially it was similar to the 70-300 f4.5-5.6 anyway. And both lenses are weather-sealed, despite the zoom on the 70-300.So then the pricing....*tear. At 1500 bills this thing better be on the camera body 24/7, right? It is at least 200-300 more than the F4 IS version. But equivalent in price if you add the cost of the teleconverter so I get where Canon is coming from. Still, I find myself not using this lens enough to warrant the price. There are two other 70-300 versions out there that perfom decently in absolute terms, but great with respect to their prices. So does this lens perform? OH YES. Is it worth its cost? Not so much for the kind of photos I usually take. Will I sell it? The funny thing is...probably not, because I already fell in love with it.UPDATE 8/31/11 *******************Since my initial review I thought more about the cost vs worth factor. First of all, Canon does not include a tripod mount with this lens. I don't know whats up with that since this is one of their longer focal length zoom lenses, and its a pricey L lens at that. Shame on Canon. There are 3rd party mounts out there, but they are few and of low quality. For the most part though, the IS stabilization is pretty darn good to make up for it. Another note I should point out is that if one goes for the 70-200 + 1.4x converter setup, then you get the slightly better magnification ratio of (.21x)*(1.4x) =~ .30x or 1:3.4 (both the 70-200 and 70-300 have native .21x magnification ratio). Take heed though, that the 1.4x converter comes at the cost of added chromatic aberration (color fringing) and distortions. The 70-300 is not compatible with the 1.4x converter or any Canon converters for that matter. It does take extension tubes, but at the 300mm focal length its not that effective (the larger 25mm extension tube gives .29x magnification ratio). There is a Canon 500D 72mm close-up filter with +2 diopter power that can change the 70-300 into a very nice .81x close-up photography lens. You would need a 67mm to 72mm step up ring however, and unfortunately the hood would no longer slip over the 72mm size filter. Another thing that consumers need to know, this 70-300 lens is not exactly white. Its more of a greyish white. Its hard to know that just by looking at the pictures.The performance of this lens still amazes me. The zoom barrel extends and retracts fluidly and there's no wobbling of any sort. It too is all metal and white. The focus ring is smooth like silk on a baby's bottom, and it truly makes manual focus a divine experience. The throw is not too long or short (120 degrees), with just enough sensitivity to make minute adjustments. It does help that the focus ring is closer to the body since I naturally hold the lens at the base. One thing that may be the reason for not including the tripod mount was that, with it mounted, it may get in the way of reaching the focus ring since the mounting area is just right behind it. The autofocusing speed is very fast and silent. The bokeh from out-of-focus planes are beautiful, and is still quite easy to get even with f/5.6 aperture because of the 300mm long focal length and tiny depth of field.With all this in mind, I would recommend this lens if you really want that extra 100mm zoom without the hassle. Otherwise, the 70-200 F/4 IS may work for you if you can simply walk closer to your subjects. I have no regrets owning this lens because its a marvelous lens nonetheless!