Extension Tubes

In addition to adapters, there are also extension tubes, used for macro photography. All of the following are native Z-mount extension tubes (e.g. you mount a Z-mount lens on them, and the tube mounts on a Z-mount camera):

  • Fotodiox — NKZ30 (35mm extension tube)
  • JJC — AET-NKZII (11 and 16mm extension tubes)
  • KenkoDG (10 and 16mm extension tubes)
  • Meike — MK-Z-AF1 (11 and 18mm extension tubes)
  • Viltrox — DG-Z set (12 and 24mm extension tubes)
  • Vello — EXT-NZ set (12 and 20mm extension tube)

How do extension tubes change things? Here's a simple example using 70mm on the 24-70mm f/4 lens used at f/5.6:

  • no tube provides 1:3.3 ratio
  • 11mm tube provides ~1:2 
  • 12mm tube provides 1:2
  • 18mm tube provides 1:1.7
  • 20mm tube provides ~1:1.6
  • 24mm tube provides 1:1.5
  • 35mm tube provides 1:1.1

If you’re trying to calculate how a specific tube works with a specific lens, you can use the following formula:

    LensMagnification + (Extension / FocalLength)

LensMagnification should be the way Nikon expresses it (e.g. .39x for the 24-120mm f/4 S lens at 120mm). Thus, for a 20mm tube:

    .39 + (20/120)
    .39 + .17
 = .56x

To get the 1:x ratio, divide the result into 1:

    1 / .56 = 1.8, so the combo is 1:1.8

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