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.

I recently spent a week using this lens with a z 2x TC. I had purchased it earlier but returned it because I needed a lens longer than 400mm.At 400mm, the IQ is phenomenal (the young bird shot plus the snail kite shots). With the 2x TC, IQ doesn't drop much at all (the spoonbill and osprey shots). Of course, you're limited to f/11, so you need a high ISO, but Nikon Z cameras handle high ISO just fine (I used the Z7II and Z9 for these shots). Yes, there is noise, but any quality noise reduction software cleans it up nicely.I've owned and used several other 100-X00 lenses including the Canon 100-400L II and RF 100-500L. The Nikon's IQ is clearly the best that I've tried (I haven't tried the Sony version), and the AF speed and accuracy is excellent, even with the 2x TC. My only complaint is that it gets quite pricy when you add TCs, and it does help to have good light due to the high ISO.However, if you can afford it, and need/desire the flexibility that this phenomenal zoom offers, then I cannot recommend it highly enough.

Works very well, Somewhat difficult to put on my Nikon 80-400mm Nikon zoom lens do to how very thin it is,but that's also part of it's appeal.

I shoot with a Canon 20D and before purchasing this lens, used the Canon EF 75-300mm f/4.5-5.6 III USM lens. I've always noticed the limitations of this lens when shooting amateur softball. I reviewed the lens lineup at the Canon website and decided on purchasing the Canon EF 100-400mm f/4.5-5.6L USM Lens. The 100-400mm is a great lens, but it can be a little soft. For that reason I decided to add the Canon EF 70-200mm 2.8/f IS USM telephoto zoom lens to my lens collection.As an L lens, there are numerous features and is manufactured with high quality materials and a higher level of dust and moisture resistance compared to the standard line of lenses. This pro quality lens is meant for serious photographers with high demands of their equipment. The construction is sturdy and consists of 23 elements in 18 groups. The four Super UD-glass elements largely eliminate the secondary spectrum reducing residual chromatic aberration. An improved 8-blade circular aperture offers a more pleasing out-of-focus image. The Canon EF 70-200mm lens weighs in at about 3.24 lbs/1,470 g, and a minimal focusing distance of 4.3 ft/1.3 m. The front thread accepts 77mm filters, be sure to get a 

good quality UV haze filter









to protect the front lens element. This lens is compatible with the 

1.4x II









 and 

2X II









 telephoto extenders.Being white, this lens looks out of place, but helps it stay cool when shooting out in the sun. Some people are concerned that being white, it attracts attention to criminals. From my experience, my 20D attracts attention regardless of what lens I put on it. In addition, I most likely have a camera bag and tripod/monopod with me to further attract attention. I personally doubt a thief looking for something to steal is taking the time to evaluate the cost of the item and are more concerned with the ease of taking something they can unload. I try to make things difficult for would be thieves and have my equipment insured as a back up.The dual IS system has two modes. Mode 1 is for stationary subjects while mode two is for moving subjects. It is recommended that the IS function is not used while using a tripod; however I have successfully used this feature while on my monopod. The IS helps to eliminate camera shake and helps stabilize the lens when shooting from a moving vehicle or in low light situations. While there are limitations to what the IS can do, it can give you a few extra stops. Just keep in mind, the IS attempts to eliminate camera movement, not the movement of the subject being photographed.This lens permits for auto or manual focus depending on how the switch is set. There is also a switch to shift from a 1.4m/4.6ft to infinity or 2.5m/8.2ft to infinity.Included with this lens are the tripod mount, lens hood, and storage case. The tripod mount is the best option to use when mounting to a tripod, helping to maintain balance. Mounting the camera instead creates an unbalanced set up that may topple over. The case is a 

zippered soft case (LZ1324)









 that can also be purchased separately. The 

lens hood (ET-86)









 is used to reduce lens flare and can protect the front element in certain situations. Often times, Amazon recommends purchasing the lens case and hood, however they are normally included with the lens.The Canon EF 70-200mm is such an awesome lens, it almost fails to compare to the 

Canon EF 75-300mm f/4-5.6 III USM telephoto zoom









. The 

EF 100-400mm f4.5-5.6L IS USM telephoto zoom lens









 is a well used option for me, but the clarity and sharpness of the 70-200mm IS lens is more refined. I doubt the 100-400mm lens will be replaced by this lens as a favorite. I find the push/pull focusing of the 100-400mm lens to be a benefit that the 70-200mm cannot replace. This lens can be used for portraits, landscape, sports or as a general walk about lens. The f/2.8L combined with the IS makes this lens a good option for certain low light situations. The features add creative versatility. The Canon EF 70-200mm IS lens comes at a price, but it is worth every bit of it.PROS:Incredible clarity and sharpnessQuiet and quick auto-focusFeatures add creative versatilityDual IS systemCONS:Heavy and bulky (This should be expected with these types of lenses)

This is so much easier to carry for me than the shoulder bag I was using. I fit my Nikon D70 with the Nikon 80-400mm VR lens attached to the camera body and I was able to carry three more lenses by changing the compartment configuration. Thank you to the reviewer who posted the video about changing the compartment configuration. This is what "sold" me on buying this item for myself.My mother purchased this and said that she cannot fit her Nikon D7000 with attached Nikon 80-400mm VR lens in the bag. She says her camera body is bigger than it is for my D70 -- true. She lives far away so I've not had a chance to see where the difficulty lies but if there is any doubt, perhaps this product would be better:http://www.amazon.com/AmazonBasics-Backpack-SLR-Cameras-Accessories-Black/dp/B002VPE1WK/ref=sr_1_1?ie=UTF8&qid=1363370878&sr=8-1&keywords=camera+backpack

Very sturdy. Easily supports my DSLR with a 100-400mm lens.

軽い❗一時期、EFレンズの100-400mm使っていたことがありましたが、重かった

何と言っても値段が安い！大きさも手頃(*^^*)7Dに100-400mmをつけても、収まります。