"X" cross on images is a common issue with wide angle lenses and variable ND filters. Physics limit the capabilities of variable ND filters on wide angle lenses.
When you enter the edge of the max range,the "X" issue may appear on your image. Because you are using it beyond its capability according to the laws of optical physics,which will inevitably cause this phenomenon.
For this series, front thread diameter is bigger than the back thread diameter.
Back thread diameter (attach to lens): 40.5mm
Front thread diameter (attach additional filter/other accessories): 43mm
Variable ND filter size other accessories size
It is a normal phenomenon if you want to use ND filters together or ND filter with other filter, like ND2+ND4,ND4+ND8,ND2+ND8 or ND2+4+8,ND filter+UV, the photo effect will become to light pink color, you
could set "white balance" as "AUTO" to improve it, but will not be completely disappeared.
When use the filters on telephoto lens,it has much requirements on material,manufacturing process and coating, Generally requires to use the high-grade optical glasses, twin polishing process, multi-coated
, we recommend K&F Nano-X CPL.
A polarizer is actually two pieces of glass set in a filter ring that screws onto your lens. The outer piece rotates, and as you look through the viewfinder you'll see the effect of the rotation. so when
attach it to lens please make sure you rotate with the inner gear-shaped ring instead of outer piece, or it will rotate for 360