It's not fast but I'm NOT using film with a fixed speed and my camera goes up to ISO 100k or so making the small maximum aperture only of concern if I have shots where I care about lower depth of field. It's extremely light and about twice the maximum focal length and a third of the weight of of a faster 70-210mm I also own. Given that I have a 2x converter as well the Canon 100-400mm operates for me between 100mm and 800mm. I got it very cheap due to a Canon discount and a work bonus but given the picture results I've had, it was easily worth it at the discounted price alone. Long range landscape shots like high mountain positions are excellent and either the low weight, stabilization or both make for sharp shots at long range even when hand held. With my 2x converter it completely fills the gap between a 24-105mm and an 800mm super telephoto instead of leaving the gap I have remaining with an existing 70-210mm zoom. I'm very happy with my Canon 100-400mm f5.6-8.

The product works good with my Canon mirrorless camera with Sigma Ef 18-250mm lens with all functions. But the cost of the product is only Rs.7500 in canon showroom. This product is in great demand and not in stock so they are selling at an extreme price. If you can wait just place an order with canon and get it at a lower price

After shooting with my older EF 70-200mm 1:2.8 L IS USM for years, I started to notice that my images were softer than those taken with my other (newer) Canon lenses. I had it cleaned and recalibrated and while the results were better, I realized that it was probably time to replace it with the most current version.The new Canon EF 70-200mm f/2.8L IS III USM Lens is somewhat lighter and MUCH sharper. I just returned from an out of state nature shoot where I used this lens extensively hand holding it mostly at 200mm. All the images are tack sharp with excellent colour and detail.The 70-200 has always been my 'go-to' lens for many situations... I love the flexibility to choose either lovely bokeh backgrounds or excellent depth of field depending on the situation and the results I'm trying to achieve. This is a GREAT lens and although it's a bit pricy, it has already proven to be a professional tool that does exactly what it's supposed to.I'm really loving my new Canon EF 70-200mm f/2.8L IS III USM Lens and am glad that I didn't 'cheap out' with a less expensive competitors product.

Once you get over the sticker shock of this lens you will be pleased with your purchase. I have had this lens for a few months now, replacing my Sigma 70-200 2.8 and it is a great lens! The IS really helps catch those shots that I missed before. The Sigma lens was good, but the Canon 70-200 2.8 consistantly delivers everytime.

I haven't made a dime in the last 15yrs doing anything other photography and I love this camera. It is very versatile. I have yet to shoot sports action with it yet, but output for all of the portrait work has been great. It handles familiarly like current Canon bodies. Menus , dials and button placement make sense. I have only used EF lenses with a Viltrox EF-RF adapter, but the lenses work flawlessly. (70-200 2.8 L IS, 24-70 2.8 L, 50 mm 1.4, 85 1.8 and a 16-35 2.8 L). Note: I do not shoot much video, so I have no opinion regarding video capabilities, handling or performance.

About a year ago I bought the EF 70-300mm f/4-5.6 IS USM lens. At the time, it appealed much more to me than its (more than three times the price) "big brother" - the lens did well for me but left me wanting MORE! I just got this lens, EF 70-200mm f/2.8L IS USM. It is worth every penny - those of you who have used an IS lens before will know what to expect in that regard, however if you have never owned a lens with canon's "L" glass, you are in for a treat! The color and image quality are far above the cheaper canon line. And the fixed f/2.8 is a fantastic advantage to have. I do mostly indoor concert photography and this lens has been a dream come true. (i know that sounds lame... check one out and you will see what I mean.!) If the fixed f stop isn't that big of a deal to you, im sure the f/4 is probably a good lens as well....however I can definitely say that this was a smart buy!

The Canon EF 70-200mm f/2.8L IS USM Telephoto Zoom Lens is nothing short of incredible. I'm using it on my Canon XTi. With the XTi's multiplication factor of 1.6 the effective focal length of this lens is 112mm to 320mm. The thought of a 112mm to 320mm lens which features a maximum aperture of f2.8 throughout its range and has image stabilization is hard to comprehend at first. After a couple weeks of use, I find this lens is fast, sharp, quiet, and a bit heavy. This lens is fantastic for portraits. It's also great for close-ups taken from about 5-6 feet away. It's far more versatile than I expected.

The walkaround lens. This very topic leads to a heated discussion among DSLR photographers.First, determine your budget, focal length, and aperture needs.If you frequently find yourself zooming out to get everything in a frame, you will want a wide angle lens such as this. If you frequently find yourself zooming in, this is not the lens for you. On a full frame body such as Canon EOS 5D, this lens becomes ULTRA wide angle. On an APS-C crop body such as Digital Rebel XTi (which I used for this review), it becomes MEDIUM wide angle. But thanks to 1.6x crop factor, this lens expands to more usable 35mm equivalent focal length of 27 to 64mm.Second, audition the lens if you can.By definition, a walkaround lens should be relatively portable. At 1.1 lbs., Canon's EF 17-40mm f/4L USM is neither super light nor neck breakingly heavy. In fact, it weighs almost the same as Digital Rebel XTi -- really nice balance. The lens feels very solid with supreme build quality that only L-series lenses offer. Although this lens is weather proof and therefore sealed against liquid and dust, I strongly recommend getting a 77mm filter to protect the front lens element. With it, this lens is made to last.In terms of looks and feel, it doesn't get much better. Its rubberized full-time inner focus manual ring USM focuses smoothly, quietly, and quickly. Since it's inner focus, the lens will not extend beyond its metal casing whether you zoom in or out. The focus window shows focusing distance from 0.28 meter (0.92 feet) to infinity. The focal length marker indicates 17, 20, 24, 28, 35, and 40mm. The lens exudes quality from tip to tip.You may tolerate heavier lens or may not mind lesser build quality of cheaper lenses. A walkaround lens will be used very often, so make sure you will be comfortable with it.This lens is famous for saturated color and deep contrast. Its images are simply stunning. At 17mm wide angle, barrel distortion is noticeable but relatively mild. From 24mm to 40mm, its images are distortion free and perfectly suited at capturing people.Vignetting (corner darkness) is minimal with mild chroma abberrations (color shadows). At f/4 aperture, details become noticeably softer toward the edges. The center region is very sharp and at f/5.6, edges remain fairy sharp. Thanks to 7 diaphragm blades, this lens can produce very nice bokeh at 40mm (blur effects).One of the most cited weaknesses is the f/4 aperture. In my experience, a bump in the ISO speed and steady hands are all you need to take well focused images indoor. On the other hand, if you are shooting with very little amount of light, you might wish for f/2.8 or image stabilizer. Although the difference between f/4 and f/2.8 is just 1 stop, my other lens, Canon EF 24-70mm f/2.8L USM (too heavy to be my walkaround lens) easily outperforms in such challenging situations. But by and large, I was not handicapped by the f/4 aperture.Some of the main competitions (sorted by price):- Sigma AF 17-70mm f/2.8-4.5 DC macro: Good zoom range with macro, and generally solid performance if you can get a good sample. It does suffer from a bit slow focus mechanism, soft corner, and chroma aberrations. Works only with EF-S mount.- Sigma 18-50mm f/2.8 EX DC: Very good value for f/2.8 aperture, but Tamron's 17-50mm is a bit better lens overall. Works only with EF-S mount.- Canon EF-S 17-85mm f/4-5.6 IS USM: This "traveler's lens" has a wider focal range than most wide angle lenses (widest among Canon) and is equipped with an image stabilizer. While it is a Jack of many trades, it is the master of none. Every lenses on this list will perform better at particular focal length. Then again, none of the lenses on this list has as wide focal range. It is famous for extreme barrel distortion at 17mm and chroma aberrations. Works only with EF-S mount.- Tamron SP AF 17-50mm f/2.8 Di II LD Aspherical (IF): This is the most direct competitor. It takes sharper images with faster aperture while costing less. Both the build and focus mechanism are significantly worse, but should be good enough for many. Works only with EF-S mount.- Canon EF-S 17-55mm f/2.8 IS USM: This is THE reference, if you can afford it. Its images have razor sharp details and great performance all around (minus vignetting, which is typical of EF-S lenses). The build quality is worse than L-series but still pretty good. Works only with EF-S mount. This is the best EF-S lens hands down.- Canon EF 16-35mm f/2.8L USM: One of the most expensive wide angle zoom lenses. It's larger and heavier, but has f/2.8 aperture.This is how Canon EF 17-40mm f/4 USM stacks up.Pros:- Among the very best build quality.- Excellent, buttery smooth, super fast front-focus system.- Top notch color and contrast. Very sharp center resolution.- Almost non-existent vignetting, generally low distortion, and well controlled chroma abberrations.- Ideal weight and size for walkaround purposeCons:- Edge softness at f/4 aperture.- Narrower focal length than most competing lenses.- Slower than some third party lenses.All in all, this is an excellent wide angle walkaround lens. It may not offer the most bang for the buck, but if you value full frame compatibility (EF lens mount) and excellent build quality, this is the default choice. This lens comes with a nice pouch and a lens hood. I find the hood to be somewhat ridiculously shaped and because the lens is resistant to flare, I do not use it often when shooting outdoor.