Hi all,

Just got a Canon 550D and have been reading / viewing a bunch of stuff on the net about photography in general, and DSLRs specifically. It always helps me to start at the very beginning and don't mind spending some time on fundamentals as it usually pays off later on, and I'm sure many of you learn the same way.

I note that a lot of the stuff for beginners to DSLRs avoid the underlying optics and try to put things in plain english, which is great for a general overview, but not so good if you want to know the 'why' behind the simplifications, and sometimes taking the time to go through more precise language / terminology ends up giving you a much better understanding.

The photonotes.org site mentioned in the 'The one, only and most mighty photo resource thread' sticky is a great site, and especially so for Canon owners, but again glossing over of underlying principles, (which again, is totally understandable as most people just want an overview) is a bit frustrating if links to more detailed explanations aren't given.

For example on focal length, "The easiest way to think of it is that it’s a numeric value, expressed in millimetres, which represents how much of a given scene (the coverage area) a lens can take in." It goes on later to give the technical definition: "The technical description of focal lengths is rooted in the mathematics of optics - it’s the distance between the focal plane and the rear nodal point of the lens, given infinity focus."

What I'm looking for are websites that would relate exactly how these lens optics applies to digital photography (i.e. not a purely optics related site). If anyone knows of a good site like that, I'd appreciate it. From my mostly repressed memories of high-school physics, I'm guessing ray diagrams are going to feature heavily.

To give you an idea of what I'm after here is a great page on F stops: http://www.uscoles.com/fstop.htm A lot longer and more precise than most beginner explanations of f stops, but for me once you go through it, it sticks in your head and makes sense much more than reading a whole bunch of shorter explanations. Is there a similar site that goes through the optical basis and explanation of the different types of lenses and their practical applications to photography?

What are you actually looking to gain?
Or is it simply for a nerdy understand of the behind the scenes? (which is fine, and I too like)

Understanding f/stops is important, sure, and that website ticks the boxes.
For your focal length example though, I don't personally see what's to learn other than "You want to see further, get a longer lens!"

Tried googling to be helpful, but with little success.

Just one of those annoying people who has to know the "why" behind stuff, I guess.
On a practical level, I find that an understanding of the principles means you can retain a lot more information, rather than if you just rote learn lists or relationships between things without really knowing why.