Marumi Macro +3 Filter DHG 55 mm

Marumi DHG Macro (Digital High Grade) Filters are used to be able to photo grave closer. They are made of extra strong tempered glass and equipped with multiple coating and moisture, scratch and dirt file. This makes it easier to clean the DHG supply filters.
With the help of a DHG front filter you can photograph closer than indicates your lens.
You run the front filter for your lens. This front filter has a dioptrie (strength) of +3. If desired, you can run 2 filters on top of each other to photograph even closer. An extension of the exposure time is not necessary. The filter is provided with a screw profile at the front to assemble any lens/filter accessories.

Explanation: DHG Macro (cross) Filter
The strength of a close-up filter is specified in dioptries, in this case +3. With the following formula you can calculate how to reduce the minimum focal length with a certain macro or close-up filter.

This formula is:
X: (D * x + 1)

Here, X is the minimum focal length of your lens in meters, and the dioptrie number on the macro / close-up lens.

Just a calculation example:
You have an objective that can focus from 55 centimeters and you use this close-up filter with a dioptrie of +3. In this case the calculation is:
0.55: (3 * 0.55 + 1) And this is the same as
0.55: (1.65 + 1) or
0.55: 2.65 = 0.21 meters, so 21 centimeters