I've always been fascinated with technology, especially how it works. For 2 year I had my own side business of repairing & reselling digital cameras & lenses. It started with me just taking apart broken cameras that were lying around the camera store I use to work at so I could learn the parts. It helped me judge the problem with customers broken camera or lens, so I could give an estimate on repair costs.
I found this visual aid that I thought would be helpful to some and just interesting to others. The the side are a few comments I had about the corresponding number next to them. Hope it helps inform you more.
The Photographic Lens
(1) Keep that glass clean so the light doesn't bounce all around in the optics. That's how you get smudgy or hazy looking photos
(2) The coating on the front element is one of the big reasons you pay the big bucks. The pro coatings on lenses are truly remarkable. When clean you can be in direct sunlight 9 out of 10 times not see any haze.
(3,4) People don't understand the cost on lenses a lot of the times. All these elements that have been ground down and polished have to perfectly line up to maintain image quality. Being off by 1/10,000th millimeter can have notable negative effects. Remember Hubble?
Recording the Image
(1) Pretty straight forward. If you don't understand aperture go further down the page or check out my aperture articles.
(2) Until you pay close to $2k+ the shutter mechanism is plastic. This is way consumer cameras shutters have a lower life span then pro cameras with metal mechanisms.
(3) Since 2010 digital sensors hands down surpassed film in all aspects. Detail and light gathering abilities film doesn't come close now cause the best films from the old days are not made anymore.
(4) Another misconception that is common with memory card is that they determine the quality of you image. They don't, its all digital,1's & 0's only. The pro cards are just a lot faster and more reliable. But your photo looks the same on a $3 card or $500 card.