Everyone has their own method of learning.. I'll just explain how I got over the hump quickly... When I started asking questions wanting to learn manual mode... the answers would be: it's a balancing act learn your triangle.. slower shutter speed more light... but oops for slow blur... F stop brings more light too.. but oops half the person is out of focus... ISO brings more light too but oops now you have noise... Practice until you find the combination to that safe to break into lol I come from a music teaching background.. If anyone has ever studied sheet music there is a formula for Every Girl Does right on the sheet music lines.. and the spaces spell out dude.. So to simplify things for me I took this approach... Shutter speed freezes time.. I'm no longer thinking of it as a light source... I'm 100% deciding how fast that shutter needs to be to freeze time... to catch a bird, a basketball game, ect... plus faster shutter less movement blurry from shaky hands or someone running, People will capture sharp water droplets with fast shutter... Hhmmm should work on anything I point to take sharp photos So I personally look at F/Stop as my decoration setting.. How much blur I want in the background vs. how much detail.. now I'm decorating my image... Now I have ISO to compensate for the difference in lost light... (oh but now you have too much noise) the fear of ISO noise comes from film days where you really had to be afraid of it.. I don't fear ISO at all First ISO doesn't cause noise... lack of light causes noise... this fear of ISO noise would force me to go back and give up my fast shutter to capture action.. and go back to changing my decoration F/stop loved getting rid of the noise 🤦🏻 ♂️ I would rather keep my fast shutter and my decoration... leaving me only one problem to solve (noise) with today's software like Lightroom, the denoise button does a great job of solving this problem for me When I shoot my brain now thinks of Shutter (freeze action for sharpness) F/Stop (my decor) ISO (my required light) It is very very rare that I am at ISO 100 even in broad daylight... I can be at ISO 1600 in broad daylight and see zero noise in the image.. due to an extremely fast shutter (freeze time) a high F/Stop for lots of background detail (decoration) And the end results (tack sharp photo) 🤗 I am just stating what had worked well for me to overcome the unclear answers about a triangle balancing act.. not saying this is the only way or knocking anyone else's method 🤗 This added photo I took with a used $50 I think 20 year old canon rebel.. and a 50mm lens using this method.. so if I can do this with budget gear.. it can be done with better gear 🤗 I'm just sharing my thoughts.. not saying this is the only way at all 🙏🏼