Super-telephoto Lens Case for Backpacking

      The hard case that came with my Canon 500mm lens is fine for storage or hauling around in the trunk or back seat, but hardly the sort of thing you can drag around in the boonies without some sort of cart to carry it in. Although I modified a fishing cart for that very purpose (and it works most excellently), there are still places and situations where even the cart is impractical. Sometimes, backpacking equipment is the only solution. At first I purchased a camouflage backpack, into which I placed several pieces of thick foam for padding, and slid the 500mm lens down inside. This was a good temporary solution until I had the time to make proper padding for it. Finally I've finished a sturdy protective canister to hold the lens inside the backpack.

      I started with some 1/2 inch thick corrugated cardboard from a large cardboard crate, the kind upright freezers and refrigerators are shipped in. I got mine by asking at the hardware/appliance store. They told me when they would have some new models uncrated, so I came back and picked up one of the large boxes and hauled it home in the pickup truck.

First A Protective Shell:
      I started by making a cardboard canister as a protective shell. The dimensions will be different for different lens, but for my 500mm I measured the diameter of the leather hood and added 3/4 inch all around for padding space (hood cover diameter plus 1.5 inches). This is the inside diameter for the canister. Next I used a protractor to draw a circle of this diameter on a piece of the cardboard, and then cut this disc out with a sharp knife. This became the inside bottom of the canister. Then I cut a second disc of cardboard, this one being one inch larger diameter to allow for the 1/2 inch cardboard thickness of the cylinder. It would become the outer bottom piece. Using two discs for the base would give me more gluing surface and make the canister much stronger. Both discs are shown in the "Cardboard canister cutaway diagram" at right.

The canister's inside diameter multiplied by Pi (3.14) gives the circumferance of the canister - in my case approx. 26 inches. I cut a rectangular section of cardboard 12 inches tall (the height I wanted) and 28 inches long (a couple of inches longer than the necessary circumferance, to give some trim for fitting and overlapping the joint). This will make the "tube" part. Next I cut notches in this piece to allow for bending the thick cardboard into a tube. Otherwise, it is so thick and stiff it simply cannot be bent. DO NOT cut all the way through the cardboard, only about 1/2 way or 2/3 way through. The diagram at left shows the measurements for the notches and an example of how this will fold into a curve. The photo below the diagram clearly shows the slight angles created as you fold the notched cardboard into a cyllinder.

      Pay close attention to the "outer skin" noted in the diagram. On one end of the notched piece, cut back the corrugation for about one inch, but be careful not to cut through the outer skin of cardboard that encases the corrugated part. Leave this outer skin so that when you join the two ends you have this extra surface area of overlap for gluing. This will make the joint much stronger.

      Now, one notch at a time, bend the cardboard at each notch and curve the piece into a tube. Then wrap it around the inner sized (smaller) disc to test fit. It should come out a little too long to close in all the way on the disc. Now, on the end that is NOT notched out for the outer skin overlap, trim back the end of the "tube" a little at a time to make it come closer to fitting snuggly around the disc, while still giving a good solid butt to the overlapped end. Once this is fitted, it is time to glue.

     Be prepared. You will need to clamp this thing when you glue it. Have some wood clamps, tape, rope or whatever you can find ready to go so you can tie or clamp this thing together when you glue it. You get one chance at this. Be ready to clamp it tight until the glue sets up. You might even enlist an extra pair of hands to help you.

      Use WOOD GLUE for this job. Do NOT use white school glue, as it will not hold. Any good wood glue will hold this cardboard as well as it does wood, and make for strong joints. Run a bead of glue inside the length of each notch. Also put glue along the inside bottom edge where the disc will go. Put glue on the two butt ends of the cylinder and the overlapping cardboard flap. Also put glue on the outside edge of the disc. Now wrap the cylinder around the disc, being sure the disc is flush with the bottom of the cylinder. Butt the cylinder ends together and clamp/tie/tape everything firmly in place. Let the glue set up overnight. When dry, you will have an incredibly strong, sturdy and lightweight canister as the basis for your lens case.

      Once the glue has dried, unclamp everything. Now you can glue on the second (larger) disc to the bottom. This provides another strong glue joint around the bottom of the cylinder sides to insure it stays a cylinder. It also helps protect the bottom from puncture. The image at right shows the finished cylinder while the bottom outer disc is being glued. I used a case of soft drinks as a weight to hold the cylinder base tight against the bottom disc while the glue dried.

     Now that the cylinder is finished, the rest of the steps all involve sewing. I will not even attempt to go into details for sewing. All my plans were in my head, and everything was a cut and fit, work-it-as-you-go process. I will only outline the general steps involved, using photos to help explain the generalities of it.

Covering The Shell:
Inner Liner:
      I will begin by stating up front that I've made no attempt to make this thing a work of art, or to match thread colors, or do fancy stitching. This is meant only as a functional item (call it a prototype if you will). So long as it gets the job done, I'm happy. Furthermore, the following steps are presented in a logical and workable order, but not necessarily in the exact order I did them, since I was feeling my way through this project a little at a time, and often had to work ahead on one part to figure out how to accomplish the step I was presently working on.

     Now down to work. I cut a circular piece of material for the bottom of the inner liner. On it I put two strips of dense gray foam about 1.5 inches thick as padding for the lens to stand on. I covered the foam with pieces of cloth, sewing them to the circular piece (orange looking cloth across the bottom of the cylinder - photo at right).

     I cut a rectangular piece of cloth for the sides of the inner liner and laid it out flat. On top of it I placed dense gray foam approx. 1/2 inch thickness to cover most of the cloth. Over that I put a rectangular piece of nylon material and sewed the nylon over the foam padding, in essence making pockets for the padding on the cylinder sleeve.

     Next I sewed the flat padded inner liner ends together to make a cylinder, and sewed the round bottom piece with padding onto the cylinder I just made. Now I have an inner liner to slide down into the cardboard canister. The last step for the inner liner is to attach it to the canister so it will not pull out. To do this, I poked small holes through the bottom of the liner and the bottom cardboard of the canister with a finishing nail. Then I slipped fine wires shaped in a "U" through these sets of holes from the inside, and twisted the wire together outside on the bottom, much like the annoying way toys are often "wired" into their retail packaging with twisted wire loops. I bent the twisted ends over and flattened them, and covered them with pieces of tape (I used duct tape). This will later be covered with a piece of foam.

Outer Liner:
     I essentially repeated the above process for the outer liner, but without any padding. This is just a simple cloth cylinder that fits snuggly over the outside of the canister (light gray-green material in this photo).

Outer padding and covering:
      To make the outer covering I first cut an oversized piece of camouflage material that would wrap around the canister with room to spare (it doesn't need to be camouflaged - it's just what I had available). The piece extended about four inches above the top of the canister. It also hung a good 7-8 inches below the bottom edge so the excess would lap over and fold across the canister base to fully cover it and the piece of foam for the bottom that I just mentioned above. It was also large enough in circumferance to cover the foam pads that will be on the outside of the canister.

     With the outer liner slipped on the canister, I next stood three pieces of foam against the canister (each about 6x8x1.5 inches thick), evenly spaced around three sides. The back side of the canister would not need added padding since it would be against my back in the backpack, and there was already some padding there. I wrapped the material loosely around the canister so that it covered the foam padding pieces. Then I pinned the outer material to the outer liner between the foam pieces, and pinned the ends of the covering material together and to the outer liner to form a snug outer cloth cylinder.

     Next I pulled the three foam pieces out, then slipped the pinned assembly off the canister and sewed the outer material to the liner where it was pinned. This attached the cover in place to the outer liner and formed three vertical pockets for the padding.

      The cover and liner were slipped back onto the canister. I hand stitched the top edge of the inner liner and outer liner (NOT the camo material) together at the top edge of the canister. This sealed the cardboard canister inside the liners. Next I trimmed and shaped the top of the outer camouflage material to form three tabs where straps would later be attached. I folded over these edges and pinned them, then neatly hemmed them. Finally, I stitched the top edge of the outer camo material (only the sections between the tabs) onto the canister's top edge where I had just stitched the inner and outer liners together. This tied the outer covering to the canister. Next I turned the canister upside down and stuffed the three pieces of foam into the pockets formed in the outer covering. With the canister still upside down I placed the round piece of 3/4 - 1 inch foam padding on the bottom. Then I folded the bottom of the outer material over the foam, forming pleats and folds, and trimming where necessary to cover the bottom. I pinned this together and hand stitched it. That finished off the canister. The completed canister and the telephoto lens it will hold is shown in the photo at left. On the right is the canister with the 500mm lens snuggly resting inside, shown from two angles.

Padded Canister Lid:
     This was probably the more tedious part - trying to figure out how to go about making the padded lid. I started out by setting the lens in place inside the finished canister. Next I cut a thin cardboard template that would fit around the lens barrel and tripod foot, and slide down a couple of inches inside the canister. This gave the shape I needed for the padding that would fill the void between the canister and lens barrel. The template came out looking something like a fat horseshoe. With this template I then cut four pieces of 3/4 - 1 inch thick foam to stack around the lens barrel to achieve enough height to come above the tripod foot (see photo one). Now that I was above the tripod foot, I cut one donut shaped piece to fit over that (see photo two), and finally one round piece of foam above that for the cap, which required only a "scoop" of foam cut out of the center on one side to finish up over the lens back cap (see photo three). The three photos below show this progression of stacking foam padding to shape the lid.

      I took the stack of foam padding out, then draped a piece of the nylon material over and around the lens. I let it drape over and outside the canister edge to form a "bowl" inside the canister around the lens. I then stuffed the shaped pieces of foam down inside the "bowl" and stacked them up again. A bit of pinning and stitching finally formed the inner lining for the lid. Again, the nylon material was used for this because it slides easily over the lens. Next I cut a piece of camo material for the outer cover and wrapped it around and over the foam. I pinned it in place to the nylon liner around the bottom next to the canister top edge, and then trimmed off the excess. I took the lid off the canister and hand stitched the outer material to the inner lid liner. Then I folded and pleated the camo material over top of the lid foam and stitched it up to finish off the top of the lid. Now the lid was fully covered and the foam layers were held in place.

     Last of all I sewed on straps made from black nylon webbing and put a snap buckle on it. This goes over the lid and insures the lens will not accidently slide out of the canister. These photos at right show the finished canister with the lid off, and with the lid strapped into place.

Inserting Into Backpack:
     Now all that was left to do was stuff the finished canister into the backpack, which is an open top drawstring style. This canister also works fine in my zipper-style backpack.

      Here are three more photos of the canister with the backpack: (1) partially inserted into the backpack, (2) with it fully inserted and drawstring open, and (3) inserted with drawstring closed.

     All that's left to do is fold over the backpack lid, snap the lid straps, and I'm ready to safely pack this lens off to those remote spots where the birds are.

     WIth this "canister" I can either use the whole backpack, or just the canister without the backpack, and seatbelt it into the front passenger seat of my truck. It provides a safe and handy way to carry the lens where I can reach it quickly. The hard case that came with the lens was far too large and cumbersome to use this way, and I was afraid it would bang up the interior of my nice new truck. This cloth-covered, padded canister case is much more friendly.