reviews the Tiffen Variable ND Filter:
Even though he says the infamous ‘X-pattern’ doesn’t show up, in the following video review (by Video DSLR Tutorial) it does:
Here are the specs:
Available in 52, 58, 62, 67, 72 and 77mm.
Provides 2 to 8 stops of light control
Thin profile ring – 9mm
Wider outer optic to help reduce vignetting at wide angles
Comes in Tiffen Professional packaging with padded black nylon pouch
Made with high quality optical glass using Tiffen’s ColorCore™ technology
Made in the USA
Tiffen does warn users in their official specs page:
Only use your Variable ND within its recommended 2 to 8 stop range. If you go beyond the “MAX”, you may experience an uneven exposure or color shift that appears as an “X bar” in the image.
…NOTE: The small indexed dots on the filter ring between “MIN” and “MAX” density settings are intended for reference only. They are not representative of a specific density (stops).