Raynox and Close Up filter Magnification Calculators

Raynox with zoom lenses or lenses set to infinity focus

Focal Length in mm of the Primary Lens
mm
Raynox filter variant
Other Close up filter diopter (Non-Raynox)

When using a Raynox adapter, the magnification of your setup depends on both the Raynox lens and your camera lens. A common formula for calculating the magnification is:

[math]\large
Magnification = \frac{Focal\,Length_{PrimaryLens}}{Focal\,Length_{Raynox}}
[/math]

When the primary lens is focused at infinity, the new working distance is approximately the focal length of the Raynox lens 

[math]\large
Working\,Distance_{Total}=Focal\,Length_{Raynox}
[/math]

For example, with the Raynox DCR-250 (which has a focal length of 125mm) and a 200mm lens, the magnification would be approximately 1.6x and a working distance of 12.5cm.

Raynox with macro lenses or lenses set to minimum focus

Focal Length in mm (Primary Lens)
mm
Raynox Variant
Other Close up filter diopter (Non-Raynox)
Magnification (Primary Lens) (2 for 2:1 lens)
Working Distance (Primary Lens) in cm
cm

When using a Raynox adapter on a macro lens, the magnification increases based on the diopter value of the Raynox adapter and the focal length of the lens. The general formula for calculating the new magnification is:

[math]\large
Magnification_{Total}= \frac{ (Magnification_{PrimaryLens}+1) * (Focal\,Length_{PrimaryLens}) }{Focal\,Length_{Total}} -1
[/math]

where,

[math]\large
Focal\,Length_{Total}= \frac{ Focal\,Length_{PrimaryLens} * Focal\,Length_{Raynox} }{Focal\,Length_{PrimaryLens}+Focal\,Length_{Raynox}}
[/math]

The new working distances are derived using the formula,

[math]\large
Working\,Distance_{Total}= \frac{ Working\,Distance_{PrimaryLens} * Focal\,Length_{Raynox} }{Working\,Distance_{PrimaryLens}+Focal\,Length_{Raynox}}
[/math]