How much Silica Gel (in grams) should I put on my 4.6L airtight container? I'm making a Drybox for my film camera.
The calculator found here (https://www.silicagelproducts.co.nz/blog/How-much-Silica-Gel-is-required) indicates that you need 5g of silica gel.
That being said, even distribution will help remove moisture better than a single packet, so consider two 2.5g packets placed on both sides of the box.
You may need more or less silica based on your environment and how quickly it is reaching saturation. Living in the PacNW, I quadrupled the recommend amount for use in a non-airtight enclosed bookcase...and then put that amount on every shelf. Mostly because this item was just so cheap to acquire and easy to use (http://silicagelpackets.com/dry-packs-dehumidifier-products/dry-packs-silica-gel-dehumidifier-canisters-40-45-750-gram/dry-packs-40-gram-silica-gel-aluminum-canister.html).
Best thing that you can do is get yourself a humidity meter and get an ambient reading. Add it and the gel into your bin and monitor. If the humidity doesn't come down a level to or quickly enough to that level to leave you satisfied, add some more gel.