Distance faces never sharp/clear. Too picky?

Question

I have been using my DSLR or years, using manual from the start, though took a step back or a while. I understand ISO, shutter speed, and I thought aperture but now I am wondering if that is my issue. So far my only solution has to buy all the lenses, fall in love with them, then hate them a short time later. A calibration issue? I feel like no matter what the settings distant faces, even just 8ft away, are never sharp or clear. I am kicking myself, I feel like I should know the issue! Am I just zooming too far and being picky, or is there actually something I am missing? I feel like the picture on the top is much less defined than the closer up bottom picture. I would love clear eyes in distance photos. Both zoomed to a 1:1 and screen grabbed.

Answer 1

Maybe you are trying too hard? You say that your images are zoomed 1:1 and that you are using a DSLR and "zooming far". For that there is a rather limited amount of unsharpness at large distances. When using a DSLR, that suggests that you are working with quite narrow apertures, possibly causing diffraction.

As a rule of thumb, most lenses are sharpest 1 to 2 stops narrower than maximum aperture. Depending on what that aperture is, you might have comparatively little depth of field. It is important that you focus correctly: try using autofocus. It is also not unheard of that mirror/matte are not perfectly aligned so that perfect manual focus and perfect image focus are achieved at different settings.

Put a dime on the road at a few meters of distance, get low in order to get a solid stretch of distances, then try focusing on the dime and make a photograph. Where is the road sharp in front, where is it sharp in back, and is it indeed the dime where it is sharpest?

Answer 2

No matter how good your technique is - no matter how sharp your lens is:

You'll always have more detail of your subject when it occupies 50% (one-half) of your frame than when the same subject only occupies 4% (1/25) - one-fifth of the width and one-fifth of the height - of the frame.

This is the case whether you get much closer to the subject with the same focal length or use a longer focal length lens to magnify your subject more from the same shooting distance. Unless the lens is grossly worse at 300mm than at 50mm, the increased magnification will result in more details of your subject.

Expecting the face in the first example to show as much detail as the face in the second is unrealistic and only sets you up for disappointment.

Beyond the sheer difference in subject size to resolution ratio, there are other reasons why images can be softer at longer focal lengths and longer distances than at shorter focal lengths and distances:

• If the camera is being handheld, the narrower angle of view provided by a longer focal length lens means the same amount of camera movement will result in more blur than with a shorter focal length lens with a wider angle of view.
• Telephoto zoom lenses very often have a narrower maximum aperture at their longest focal length than at shorter focal lengths. The forces one to extend the exposure time due to the narrower aperture when shooting at longer focal lengths compared to shooting with a wider aperture at shorter focal lengths. This extra exposure time exacerbates the additional blur caused by the same amount of camera movement due to the narrower angle of view.
• Lower grade telephoto lenses tend to be softer than lower end normal and wide lenses. Telephoto zoom lenses tend to be softest at their longest focal length. So do wide angle to normal or wide angle to telephoto zoom lenses.¹
• Though we often think there is nothing between the camera and our subject that affects optical quality, the air through which the light from our subject travels to reach the camera affects the end result. Things such as moisture or dust can scatter a portion of that light and cause the angles at which light rays from a specific point fall upon the front of the lens to vary. The more air (and moisture and dust, etc.) there is between our subject and camera, the more distorted the light from our subject is by the time it reaches the camera.

_{¹ Please see Roger's Law of Wide Zoom Relativity}

Answer 3

It comes done to the size and quality of your sensor. Then the quality of your lens.

I have an Sony A6500 with a 24MP APS-C sensor and a Sony7Rii with a 42MP Full frame sensor. The difference in detail and sharpness is staggering.

On the Sony A6500, I have use a wide angle zoom 10-18mm and a 50mm prime lens. Forget the difference in lens angle here... the difference in how sharp the 50mm is again huge.

Try using at least f8 and shutter of at least 1/250, iso under 200. Use spot focus.

If you do not want to update your gear, the only option left is to use Sharpening in Lightroom or Photoshop.