i wanted a camera bag that dont occupied too much space, otherwise I never bring it with me. and I wanted it cheap.
and you can still carry it with the camera straps.
you need: fabric, spongy materials, inner tube

Step 1: CUT PIECES

cut the fabric(X2 each pattern) and the sponge like the pattern in the picture (measure your camera)

Step 2: SEW FABRIC TO SPONGE

sew each pieces with same pattern together: a layer of fabric, a layer of sponge and a layer of fabric.

Step 3: SEW TOGETHER

sew pieces together like in the pictures

Step 4: MAKE CLOSING STRAPS

make a ring big like the circumference of your lens with a road bike innertube.
sew a piece of innertube from a side to the other of the back part of your camera bag, incorporating the ring (see photo because is difficult to explain)