To capture good photographs, quality cameras and lenses are essential and we never mind in spending some huge money in buying those. But when it comes for maintenance, we often fail. Cameras and lenses are extremely sensitive to moisture, dust and fungus in our atmosphere and it is very essential to maintain it properly.
Lenses become foggy as and when dust gets deposited over it and even growth of fungus is quite common when it is exposed to moisture. When we spend a huge amount in buying those expensive equipments, it is not necessary to spend same amount for buying materials to protect it. Instead we can create our own protective mechanism with the help of ordinary materials which we use and come across day to day life, which may cost less than Rs.100/- (Indian Currency).
If we adopt the below methodologies meticulously, we can save our quality camera and lenses which may cost several thousand rupees. 
Choose a plastic airtight container with appropriate size as given in the picture. Check the circumference of the container and ensure that it is at least 2 to 3 inches bigger when compared to the circumference of the lens, so that lens can fit in easily.
Identify a thick thermocol sheet and carve a circular piece out of it. Ensure it is marginally less in circumference when compared to the bottom of the airtight container. Place the thermocol as shown in the photograph which in turn will provide a cushioning effect to our lens.
Carve 2 more thermocol pieces with same the circumference equivalent to the lid of the air tight container. Choose a piece and carve another piece with the same circumference equivalent to the lens rear cap as shown in the picture. Now place the lens inside the thermocol and then into the container. Cover the lens edge with another thermocol.
Drop a tiny packet of silica gel inside the jar and close it completely. Now let’s see the reason behind dropping a silica gel packet.
Silica gel is a drying agent which can absorb moisture. The colour is blue initially and if it absorbs excess of moisture it will turn white or pink in colour. If it happens replace the silica gel packet with a new one and check whether we have closed the air tight container properly or not.