MOFAGE is teasing its upcoming POCO II Drop-In Filter Adapter ahead of NAB in Las Vegas. While there isn’t any official information available, it does look like you can interchange both the front and rear parts, so it won’t be tied to just using PL lenses.
I reviewed the Mofage POCO drop-in filters adapter on the site back in 2022. In case you are not familiar with the product, The MOFAGE POCO PL to E/RF/L/Z Mount Adapter combines rear filters with adapters. The POCO is compatible with most PL mount lenses, although there are certain lenses (such as rear anamorphic) that will not work due to clearance issues.
I really liked the Mofage POCO drop-in filters adapter, and I actually chose it as my favorite camera accessory of 2023.
