In my short few years of using a wide range of Canon cameras, I can say this about Canon system (but applies to any brand, mostly):
1. Never jump into a new system as it gets newly released.
- When EOS M first came out as their first MILC, I just got into taking photography more seriously and I bought it. It is an okay entry-level system but knowing what came after, it's really underwhelming after that.
- And when EOS R first came out into the full-frame mirrorless camera scene, it was the case too. It's only when the R5 and R6 came out that the brand became on-par with the state-of-the-art (with Sony).
2. Lenses can last a long as time, save $$ by buying second-hand.
- I bought second-hand lenses as much as I bought brand new. Unless there are damages, all you need mostly is spending a significantly small amount to service them. If you buy new, you'd service them anyway.
- Newer lenses are always better in optics and functionality but it is not the be-all-and-end-all.
3. Buy lenses based on what you need and not what you want
- I only bought a zoom lens because I was using it for event shooting
- I got one prime telephoto and one telezoom, both for birding. I got the zoom later because I wanted more reach than the prime but not spend 20k on a 600mm f/4.
- I use my prime lenses extensively and swapping them based on what I wanted to take.
- I do have lenses that I bought that I seldom use and regretted buying.
4. Megapixels is not everything and I find the MP war between brands dumb.
- Buy a Sony A7R IV or A1 and you get crazy amount of megapixels. But it is not the only reason why they are good cameras.
- I generally find it a hassle to process large MP photos and you get pretty good photos even with <18MP cameras. It's the brain behind the camera that counts most.
5. Sensor size is not everything.
- I used APS-C cameras and I'd still choose my 7D-II over a 6D-II or 5D-IV because I wanted the 10 FPS it offers. The full frame equivalent DSLR is the 1DX-II and 1DX-III, which is overkill for my level of use.
- If full frame is objectively, unambiguously better than a cropped sensor, then wouldn't medium or large format be even better? Why stop at FF?
- Side note, full frame is referring to 35mm film size (36 x 24 mm), or the 135 film and it was considered small back it the good old days of film photography.
- If like me, you crop your photos to get the best composition in birding and sports photog, then the benefits of a FF is mostly neutralised (less the benefit of the DOF and the light capture).
- Perhaps proponents of only using FF cameras are just gear envy snobs.
6. The best camera is the one you are using
- I don't always shoot with a FFMC or DSLR. I use my phone camera almost as much as my DSLR/FFMC, because I don't always carry my Canon cameras with me.
- Just because the camera isn't as good in specs doesn't mean it can't take a good photo. Like I said, it's the brain that is most important.