You've got a snazzy digital camera, but you want to take it into a wet, dusty environment. Protect it with a simple zip-lock bag and a filter.
Step 1: Gather Materials
- Zipper lock bag: 1 Gallon size is fine for a DSLR and a medium zoom lens.
- Filter to fit your lens: You probably want a transparent "Skylight" or "UV" filter. I got cheap ones for this project because I expect them to take some abuse.
- Sealing tape: I used electrical tape, but duct tape might provide a superior seal. The tape will only touch the bag and the outer ring of your filter, so if it leaves gunk behind, it's no big deal.
- Marking implement: Fine-tip sharpies write well on plastic bags.
- Cutting implement: A small pair of scissors works well.
Step 2: Trace Filter
Trace the outline of your filter on the zip-lock bag. You don't have to be very precise, just get the basic shape and size down.
For short lenses you can put the filter smack in the middle of the bag. This will help to keep the zipper away from the controls. For longer lenses, you may have to arrange the camera diagonally.
Step 3: Cut Filter Hole
Cut a hole in one surface of the bag. It should be a little smaller than the filter. I found a quarter-inch margin was about right.
Step 4: Put Filter on Lens
Screw the filter onto the lens, but leave a gap between the two.
You can also do this using two filters and attach the lens later, but that means you're putting more layers of glass and air in front of your lens, so you risk more reflections and worse optical quality.
Step 5: Put Filter and Lens Into Hole
Push the lens and filter through the hole in the bag, from the inside out. Get the stretched hole to fit snugly in the gap you left between the filter and the lens. Then finish screwing the filter into the lens threads.
Step 6: Tape Around the Hole
For extra sealing, wrap tape over the joint you've just made between the filter and the bag.