Superb light transmission, Impeccable sharpness and clarity, Excellent image quality with unbelievable contrast at the highest magnifications. These are the main traits of the superior ED glass and in the past you would have had to pay a hefty price for that. Not anymore: the 7179 model is supremely affordable and is therefore a dream come true for long distance shooters, by virtue of its huge 5x-40x zoom power to go along with an array of truly incomparable features.