SuperflyTNT Loc: Manassas VA

It doesn’t matter. The fact is I find value in separating focus from the shutter no matter what camera I’m using.

manpho789

Thanks guys, a lot to think about.

manpho789

My camera is a Nikon with AF-S, 18-140mm zoom lens. It evidently goes only up to f5.6. That’s because the iris is not independently adjustable, but is mechanically slaved to the zoom out. I would like to close up the iris more, which on bright day would give a sharper image and more DOF. Am I misunderstanding this? Is the f number independently adjustable somehow? One problem I was having with auto-focus was the focus “hunting” at times.

CHG_CANON Loc: the Windy City

You seem to be struggling with a few technical issues related to your digital camera equipment. Your NIKKOR 18-140mm DX AF-S f/3.5-5.6G ED VR lens is variable aperture in that the maximum aperture varies over the zoom range. At the wide 18mm end, the lens can achieve an f/3.5 aperture. At the long 140mm end, the lens maximum aperture available is reduced to f/5.6.

However, those values are how 'wide' the aperture can achieve. The aperture is fully adjustable to smaller values, also varying at different focal lengths, for 'small / minimum' values of f/22 to f/36.

For digital photography, although the small / narrow values are available in this f/22 - f/36 range, consider going no smaller than f/13 at any focal length. If you perform a separate google search of 'lens diffraction' you can independently research the diminishing returns in overall image sharpness as the lens aperture gets smaller and smaller on lenses mounted to varying pixel-density sensors.

You mention wanting sharper images in bright sunlight, try the range f/8 to f/11 for this lens to maximize your results.

manpho789

Thanks, I just discovered the adjustment for f number.