The resulting case is waterproof and protects the delicate camera from scratches and mild shocks (i.e. knocking over on table, banging around in your backpack/daypack). The case is lexan (polycarbonate), a pretty tough material, but still, dropping it onto a concrete floor will probably break the *internal* mechanics and glass of the camera due to momentum, even if the exterior will be largely protected.
A friend cracked the glass of the LCD screen on his camera, which would not have happened if he had it in this case.
Step 1: Buy a Witz Brand 'Keep-It' Case, Clear Style
Or, just google "Witz Keep-It Clear". If you have an REI store nearby, you can order online and have it delivered to the store for pick-up with no shipping charges.
Description of the case, from Witz' website
Size: 2.7" wide x 4.3" high x 1.3" deep
Features: Translucent color / Nylon lanyard with breakaway clip (or carabiner) / Portable size / 250% larger than See-It Safe® / 7 colors
In revision 0 of my case, I used some off-brand clone of the Witz case, which turned out to be slightly too small to hold my SD-500, but which might have held a slimmer SD-400 perfectly fine.
I used the type with a lanyard (which I later shortened to function as an extra locking strap); the carabiner style might also be useful.
Clear (colored or not) is nice, but not essential. The padding you'll put inside will obscure most of the view anyway.
Step 2: Line the Case
I used what I had laying around the house--
- some adhesive-backed self-stick velcro (the soft loop side only)
- a suede leather elbow patch
basically, any soft, non-scratching materials that have some cushioning value. If your camera is small and there is a lot of slop inside the case, you'll want thicker, cushier materials. If your camera is tight fitting, you'll need thinner materials. Note: avoid using no liner- I did this on revision 0 of my case, and the case plastic rubbing directly on the camera body left small scratches on the camer, and did nothing to protect the camera from shock (in case of dropping, for example).
Basically, choose materials for their softness yet sturdiness, with a cushion backing. Woven fabrics are probably not the best since little dirt and sand particles might get lodged easily and scratch the camera.
Loop-side velcro is great because it is easy to mount (just stick to the case). See the white materials I used.
The suede I used was harder to mount-- I used double-sided foam tape at the rim (where the case was slightly larger due to the tapering of the case. I left the bottom edge of the suede unfastened; its own rigidity, plus the slab of foam I inserted at the bottom of the case, are sufficient to hold it in place... plus the fit is smooth so there is very little friction between suede and camera anyway.
Another easily obtainable material you could use-- Moleskin (flannel, really, used to treat foot blisters). It is good because it's soft, has some thickness, is self-adhesive, and can be layered easily for thickness. And you can buy it at drugstores or maybe even REI.
Depending on the length of your camera, you may nee a small piece of soft urethane foam to stuff in the foot of the case to take up space (i.e. from an old pillow or camping pad). I also stuck, under the foam, a dessicant packet from a bottle of vitamins, to absorb any excess moisture that gets inside the case.
The camera should 'just fit' and slide in, with no slop or play that might cause vibrational damage in case of shock. It should not be tight or require force to insert or remove; you don't want pressure on the camera, especially on movable parts like sliding shutters, buttons. When fitting your lining, check your lining material for tell-tale signs of pressure points where bulgy parts of the camera (for example, the frame around the LCD, dials, and knobs) are getting extra pressure and compressing the lining material. Try to minimize these.
Note: for my camera and my case, I had to remove the wrist strap from the camera itself, for two reasons. One, there is not enough room in the top of the case, and it interferes with getting a nice fit. Two, more importantly, the strap has to be carefully bunched up in order to close the case, and that interfered with one of my goals of quick in, quick out (if this sort of protective case is not quick and convenient to use, then there is a tendency to not use it all the time, leaving the camera unprotected). A friend who built one of these with a smaller camera had plenty of space and chose to keep the strap attached.
Step 3: Trim the Lanyard
I also shortened the lanyard to fit exactly around the case, acting as a sort of 'safety' closure in case the main latch breaks or is opened accidentally.
Step 4: Add Latch Protector
So I fashioned a giant rubber band out of a cut-up old bicycle inner tube (useful material!).
A previous revision of this, I used a large broccoli band. But without a handle to pull the band away from the latch, it became annoying to use. The knot in the inner tube provides a convenient and quick handle to pull the band away from the latch, making it very quick and easy to double-lock and unlock the latch.
This case is all about protection without reducing usability or making it slow or inconvenient to access my camera.
Step 5: Protect LCD From Scratches
I bought some cut-to-size PDA screen protectors from Fellowes at a local store. The ones customized for a particular PDA may work if you can cut them down to the size needed.