Pinhole cap with interchangeable pinhole inserts for Pentax 645 cameras. Focal length is 68.5mm. F stop is 196 with 0.35mm pinhole insert. Pinhole was made from brass shim stock 0.001" or 0.0254mm thick. Pictured camera not included. Pinhole inserts shown for illustration purposes. Number of inserts included is as outlined bellow. Recommended pinhole size for Pentax 645 bodies is 0.35mm. Pinhole cap available in following sets: Set #1 - Pinhole cap, 0.35mm pinhole insert Set #2 - Pinhole cap, 0.25mm, 0,35mm and 0.45mm pinhole inserts Set #3 - Pinhole cap, 0.30mm, 0,35mm and 0.40mm pinhole inserts Set #4 - Pinhole cap, 0.25mm, 0.30mm, 0.35mm, 0.40mm and 0.45mm pinhole inserts Lens cap - no pinhole - This is option to purchase Lens cap only without pinhole with M22 thread. Perfect choice if you have one of other Medium format or Large format sets from our other listings. Since this shim stock is extremely thin, it's possible to have some wrinkles/curvature due to temperature variations. It's normal and it doesn't affect image quality. Pinhole cap and inserts are 3D printed from ABS for durability. Inserts thread size is M22. Focal length can be varied with extension tube or macro bellows. There are several online calculators and phone apps that can be used to calculate optimal pinhole size for specific focal length and corresponding F stops. Lens caps also available in our other listings for following cameras: Hasselblad V mount, Mamiya 645, Mamiya RB 67, Pentax 67, Large format in Copal and Compur 0, Copal and Compur 1 and Copal and Compur 3. You can acquire full set of pinhole sizes and use with with any of these adapters. For Sinar and Speed Graphic there is a lens board available with M22 threaded hole to use insert directly without adapters. Combined shipping available for any products. Actual shipping fees charged. Products will be shipped within 3 business days. Customer responsible for all taxes and duties on import. We are not able to change declared value of the product.