Astro-Photography Filter R640 ( 52mm )

KANI Astro-Photography Filter R640 ( 52mm )

SKU Number : K14016

PRODUCT DESCRIPTION

- The filter is Astro-Photography Filter R640 .

- The filter diameter is 52mm Circular type.

- The filter glass is made by B270 glass of German SCOTT

- The filter both sides are ultra-precisely polished to maintain a high filter flatness accuracy.

- The filter is water-proof, oil-proof and dust-proof with Premium Coating System.

This filter was developed under the supervision of Dr. Akio Nakanishi in response to requests from Astrophotography fans.
Because this type of filter, which has been discontinued by major manufacturers due to low sales volume, has been commercialized because it is a filter that nebular photographers want.
The glass thickness is only 1.1mm to reduce the effect on image formation performance. (Normally 2-2.5mm). Good surface accuracy and multilayer coating differentiate this filter from conventional products. 

The exposure multiplier of the R-640 filter is approximately 5 to 6 times for models with high sensitivity to Hα rays, such as the manufacturer's genuine astro models and modified models, and 10 times or more in areas with light pollution due to its extremely effective light pollution reduction.