The Canon EF 70-200 mm f/4 L IS USM is a high-end professional telephoto zoom lens for FF and APS-C format. It guarantees high optical, technical and ergonomic performances and was in production from 2006 to 2018. Equipped with an optical scheme composed of twenty elements in fifteen groups, one of which is fluorite and two UD (ultra-low dispersion glass), it appears to be very sharp at all focal lengths already at f4 with further improvement by closing the aperture even just a little. The latter, made of eight blades with an almost circular shape, has the advantage of making the blurring particularly pleasant. the lens can be equipped with teleconverters and many of them are also available from Canon. Another advantage of the Canon EF 70-200 mm f/4 L IS USM is the tropicalization which makes the lens resistant to dust and humidity. If we add to this that the minimum focusing distance is one meter and twenty, it is easy to understand how the product contains many features. The contained weight and dimensions (760 grams and 172 by 76 mm), the internal ultrasonic focusing (USM) and the zoom, also internal, guarantee the Canon EF 70-200 mm f/4 L IS USM good portability and convenient use. Finally, the +4 stop image stabilizer, the solidity and attention to detail typical of Canon make this lens not only extremely versatile, but also almost indispensable, both in the kit of a professional and in that of an amateur photographer.