Should digital photos need to be "sharpened" in post process?

[PixFixer]

I am not trying to stir up a hornets nest but at a recent photo club meeting, one of the member was showing pictures from his trip out west. In the ensuing conversations about post processing, an off-hand the comment was made, that digital photos almost always need to be sharpened in post process.

I have noticed a lack of sharpness in some of my photos but I attributed it the auto focus selecting the wrong subject and/or the aperture priority always seems to select the smallest f values, with the least amount of depth of field.

I do not know if it makes a difference in sharpness, but most of the camera club folks prefer to work in the JPG format rather than RAW.

I was curious if there was some merit to this off-hand comment?

I usually set the cameras' processor to some mid point of sharpness. Then I do the rest in post. Always. The thing I see is that all to many people don't understand how sharpness works and they end up with that 'salt and pepper' look or a white and black line at edges. Sharpening has to be applied in a very thoughtful way, but first, experiment and learn how it works. Zoom into the displayed image at the small hard edges and see what is happening. You may have to back off some.

 

[johngpt]

Looks like the subject has been very well covered with everyone's comments.
I liked Derrel's comment regarding sharpening in stages, a little at a time.
JC's comment about his Fujis rarely needing sharpening was interesting. I shoot with the Fuji X-T1, X100F and the old X100 (this one through an IR filter). I believe JC shoots through Fuji prime lenses. My X100F which is essentially a prime rarely needs sharpening. Sometimes I even need to give 0.5 to 0.8 pixels of Gaussian blur as there are times the sharpness is so good as is, the image looks unreal.
The Fujinon 55-200 lens is the one most commonly on my X-T1 and that combination often needs a bit of sharpening.

I only shoot in RAW now that I'm not shooting high school sports, and I always pull Lightroom's sharpening slider to zero as I prefer to do sharpening in Photoshop after all other editing.

For many years I sharpened in Photoshop using the high pass filter and the layer set to Overlay or Softlight blend mode.
I'd mask everything but the areas I felt needed sharpening.
A few years ago (maybe 10 now?) I learned about luminosity channels and masks, so as well as the other masking I had been doing, I'd often use a mask from the "darks" channels so that the sharpening doesn't show up in light pixels. This eliminates the lighter halo that can occur with any style of sharpening. I learned about confining sharpening to only the dark pixels when reading Tony Kuyper's tutorials on luminosity channels. Another way to eliminate light halos is in Photoshop's layer Blend If dialog, dragging the This Layer white slider to the left until the halos disappear.

Then in 2017 I dove deeply into Dan Margulis' Photoshop LAB book in which he wrote about Unsharp mask being used on only the Lightness channel through a mask created from an inverse of the Find Edges process. This confines the effect to edges. When that is combined with masking through a darks channel the effect is very refined.

Opacity of the sharpening can be dialed back depending upon the final output.
If the final output is for web, very little sharpening is usually needed. Sometimes de-sharpening is needed depending upon the quality of sensor and lens.
A couple years ago I resolved to print more and discovered that quite a bit of sharpening was needed for printing.
I'm using a Canon Pixma Pro 100.
The image on screen would look so over sharpened that I'd gag, while the print of it would come out looking marvelous.
Live and learn.

Why am I commenting after so many other folks have made excellent comments?
1) To mention different levels of sharpening are needed depending upon final output.
2) To mention a couple methods for confining/refining sharpening to prevent halos.
3) To mention a couple sources from which I learned these refinements; Tony Kuyper and Dan Margulis.

Thank you for bearing with me.

 

[stevn de lozada]

I shoot Fashion and for me garment and design details as well as how the model looks are important, so unless your intention is a blurry image for effect or you are color grading or utilizing Lightroom Presets for the continuity of a series of images there may always be some degree of sharpening as one of many tools that you may have available, but you need to use a light touch.

 

[stevn de lozada]

 

[Original katomi]

I am still trying to get my head wrapped around sharpening.
I must have in camera setting as most of my pics are sharp. I put the unsharp ones down to user error

 

[freixas]

I'm rather late (as usual) to a rather busy thread, but I might have a few interesting tidbits to add.

Back in 2010, I wrote a paper on sharpening within Photoshop CS4. It decodes, in detail, how the PS unsharp mask tool works and may provide the only correct explanation of how the threshold setting works. Not even the Photoshop CS4 manual had it right! I start with a math-free overview and then provide the supporting math and the reverse engineering I performed. Citations in the first section lead to supporting details in the second.

Most people will class the document as TL;DR, but there are some interesting tid-bits for those who persevere.

One possible source of image blurriness not mentioned so far is that having mosaic filters on the sensor means that every pixel has two color channels that are guesses based on adjacent values. I know little about the demosaicing algorithms, but I can speculate that some might interpolate the missing values in ways that create a sharper image--if so, your RAW processor might be performing some default sharpening and a switch to a different RAW processor might generate different results.

The choice of radius in an unsharp mask depends on the pixel size and viewing distance. A radius of 1.2 for a 300 PPI print and a radius of 0.4 at 100 PPI might yield the same sharpening effect if viewed from the same distance. We never have control over viewing distance (and displays these days can have wide-ranging pixel densities), so "perfect" sharpening is not achievable; still we can make some reasonable assumptions and get decent results.

Some people have explored arying sharpness based on luminosity (e.g. shadows vs. highlights). It might be better to vary it depending on a frequency analysis of the image. Low frequency areas might need little sharpening. In high-frequency areas, sharpening can often make he image noisy. So perhaps applying the most sharpening in the mid-range frequencies might be best; I don't know if anyone has experimented with this.

In the end, there is also no perfect sharpening solution because sharpening is an artistic decision. There are approaches that work for most images most of the time.

 

[johngpt]

Back in 2010, I wrote a paper on sharpening within Photoshop CS4. .

Tony, I'm looking forward to reading that paper. I'm still using Ps CS4 but mostly it's because the nerd part of me is really interested.

 

[johngpt]

I've read through your paper a couple times. It's interesting. I had trouble with understanding the subtracting of layers and probably need to see you actually do that in Ps and then also be shown from where values are taken and plugged into the various variables. Thank you for sharing this info.

I'm not sure if it will change the methods I use for sharpening, but I like attempting to have an understanding of the underlying processes of anything I do.

I think that's enough for now as anything further might be hijacking the original poster's thread.

 

[weepete]

Well, there's definatley an extra level of sharpness that can be gained in post if you want it. I normally apply some level of sharpening to all of my raw files.

What I tend to do is apply a global level of sharpening, then quite heavily use the mask a lot out before finalising my tweeking then very last step I'll redo the shapening settings to the final image with the masking applied. This seems to give me the best final result.

I'm a lot lighter touch than I used to be, but I've had a few of my recent shots (heavy crops of BIF) ended up under sharpened and definatley showed in the final reult. I ended up going back through them and re-doing the sharpening 3 times before I was happy.