Quote:
Originally Posted by Domol
paul,
you siad that you need to "stopped down to around f/3", so what happens if you use the full 1.8 apature? Fuzzy?
Also what's an "L"............that's right i'm a newbie!  |
Using a lens "wide open" will make the imperfections/errors of the glass in the lens more obvious... for me and my work i always stay between 1 stop from fully open and 1 stop from fully stopped down.
so for a 50mm f1.4 i would shoot between f2 and f11, as a general rule the "mid-point" of a lens i.e f5.6-f11 gives the lenses sharpest result. this is because the lens is using the centre most bits of glass in the lens which does not have as much curvature as the outer parts of a lens would. aspheric lenses elements offset this.
if you close a lens all the way down the lens will suffer from diffraction, which is where the image is still sharp but light bounces off of the aperture blades, affecting image quality.
finally an "L" lens is Canon's pro line of lenses but unfortunately they come with a pro price as well. they feature things like weather proofing, more coatings, and various high cost elements like ED and aspherical elements.