Can you please explain me what is 4.5 - 5.6G in a lense description.And how it is different from other generation of like 3.5G or 6.5.

"Nikon AF-S DX NIKKOR 55 - 300 mm f/4.5-5.6G ED VR Lens"

  • \$\begingroup\$ Some of it is covered here: photo.stackexchange.com/questions/496/… \$\endgroup\$
    – MikeW
    Jan 18, 2015 at 7:56
  • \$\begingroup\$ I'd say it's all covered there, with the possible exception of variable aperture zooms. That can be easily fixed with an edit though... \$\endgroup\$
    – Philip Kendall
    Jan 18, 2015 at 22:07

2 Answers 2


That simply refers to the Maximum Aperture of the lens.

The terms in that lens name are as follows:

  • AF-S - Auto Focus - Silent
  • DX - Designed for Nikon crop sensor bodies
  • 55-300mm - Focal length range of the lens
  • f/4.5-5.6 - Maximum aperture of the lens at min and max focal lengths
  • G - No manual aperture control on the lens, aperture must be controlled by the camera body
  • ED - Extra-Low Dispersion glass
  • VR - Vibration Reduction - basically reduces the effect of camera shake.

So generally none of that refers to the Generation of the lens, just the features and specifications of the lens. There may be a "II" on the end of some lens names indicating that it is the 2nd version of that lens.

There are other acronyms you will see from time to time, there is a good reference on the Nikon site: https://support.nikonusa.com/app/answers/detail/a_id/9919/~/glossary-of-nikkor-lens-terms

  • \$\begingroup\$ The "II" designation is applied to successive versions of the same lens where the alphabet soup and basic specs are otherwise the same. The 70-200 f/2.8 and 18-200 f/3.5-5.6 are examples of where they did this; the three versions of the 24-120 that have been released over the last 20 years are examples of where they didn't. \$\endgroup\$
    – Blrfl
    Jan 18, 2015 at 15:49

4.5-5.6 mean maximum aperture of the lens. It is variable so as you zoom it change, 4.5 at 55mm and 5.6 at 300mm.

G mean aperture is managed from the camera. You do not have aperture ring on the lens


Not the answer you're looking for? Browse other questions tagged or ask your own question.