i use a 28mm f/1.8. I'm very new to this hobby and this is my only lens.
Initially when i bought it i took all my pics wide open...but then i realised images were a little soft.went online to read more detailed reviews of the lens to see which f-stop is sharpest etc etc. and i found that softness when wide open is a known characteristic
buy viagra of this lens. since i feel optimal f-stop is lens dependent...might be a good idea to read reviews first
i still use 1.8 in very low light cos i refuse to use flash. if 1.8 doesnt
buy levitra work as a last resort i bump up ISO to 400.Still cannot? Then i dont bother taking the pic lol. if i can afford it, i go to 2.2 (if my hands feel steady or there is some lighting i can use).
Normal outdoor daylight portraits i go with 2.8. Produces nice sharpness. This is my default f-stop in canon Av mode
If i'm taking pics in a cloudless day in the middle of the afternoon, maybe 4.0 (for my lens, there appears to be minimal improvement going from 2.8 to 4, so 4 for me is more of a 'luxury' handhold f-stop if this makes any sense)
Landscapes i would use 8.0 but only if i had a tripod or a place to rest the camera on, unless very bright daylight.
I wouldnt go any higher unless i absolutely needed the DOF. Diffraction is an issue that crops up on my lens when going above 8, apparently
Its all lens specific so i'm sure every user here can tailor their strategy to meet the lens based on the wealth of technical lens reviews available on the web
My particular most used is 2.8 (about 70% of the time) as thats where the sharpness is at, and handholding shots at that f-stop is not an issue most of the time. about 10% of the time i use 2.2, 15% 1.8, 5% 4 or 8
My note to self for future upgrades is for my next lens to have close to optimal sharpness at maximum f-stop as i realise a large portion of my shots are handheld, and at night