Sharpening techniques (lizard subject)

Hello everyone,

At work I take pictures of plant diseases with a Nikon D700 installed on a tripod.
My standard setup is: ISO 200 - F9 - 2850 K (as white balance setting), white or black paper as background. As source of light I work with an Elinchrom system.
Generally I take a single shot (no focus stacking to save time…).

Today, I would like to ask for some very general suggestions to improve the sharpness of the RAW images.
Maybe someone knows some unusual trick on this matter.
I am aware there are plenty of experts on this forum :slight_smile:

Usually, I work on Windows 10 with RawTherapee and it suffices to activate its basic settings (SharpenEdge, local contrast, SharpenLocal etc) to get some very good results as far as the sharpening is concerned.

To recap: Do you have some special tricks to improve the sharpness of your images?
I am aware it is a very genaral question and there are tons of books on this subject but yet… :slight_smile:

Here is the jpeg (very compressed to post here) result of my attempts with RawTherapee:

Here is the pp3 with RawTherapee 5.6 where I have only activated some of its basic sharpening tools:

lucertola_macro.NEF.pp3.tif.out.pp3 (11.8 KB)

Most of all, here is the link to download from Dropbox the Raw file (LIZARD_SHARPENING_TEST.NEF, 9 mb):

Thanks in advance for any suggestion! :slight_smile:

In the Sharpen module, try the RL deconvolution. This is an implementation of the Richardson-Lucy sharpening algorithm, which I like quite a bit.

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Left without sharpening, right with:

Hello everyone,

@heckflosse
Wow!
Can you share your pp3 to take a look at your settings to achieve such a great result.

@paperdigits
Thanks a lot.
Didn’t know this technique.
I am an old-fashioned photographer and I don’t know very well the software part of this trade :slight_smile:
I am just checking its documentation right now:
https://rawpedia.rawtherapee.com/Sharpening

P.s:
one problem with this image is the very end of tail of the lizard which is out of focus.
The animal was still alive and I didn’t take multiples shot (to focus stacking them later on…) :slight_smile:

Sure:

LIZARD_SHARPENING-TEST.NEF.pp3 (11.9 KB)

Hello @heckflosse

First off, thanks a lot for your help!

Just diffed your previous pp3 file.
Only a question…

Why did you opt for the Method=rcdvng4?
I always work with the Amaze method…
Taking a look at rawpedia [1] it looks like your choice might be better off for images with round edges. Is that so?

[1] https://rawpedia.rawtherapee.com/Demosaicing

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Well, that’s just my preset. I almost always use one of the dual demosaicers and rcd is faster than amaze (though still vng4 being the bottleneck here).

I prefer Amaze for e.g. architecture (with long straight lines) and rcd for nature (more random lines)

@Silvio_Grosso

Being also a D700 shooter, some hints:

  1. RL deconvolution usually works very well for D700 raw files
  2. if you go past diffraction limit, you can raise the RL Amount even more without getting artifacts. e.g. try 0.85 for your F9 shots or even larger values for F11
  3. Dual demosaicers help to avoid sharpening artifacts in flat (oof) regions

Edit: see also My sharpening workflow for base ISO mages with the new features in RT (aka extreme pixel peeping)

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@Silvio_Grosso I’m also a plant pathologist, so if you can share photos of diseased leaves, maybe as a Play Raw, I’ll be on it!

Hello @heckflosse

Thanks a lot again inded for your suggestions!
I do appreciate your work on RawTherapee.
The only commercial software I am still using is Affinity photo for focus stacking tasks (tried Hugin and Enfuse but the duo is a bit too “cumbersome” for me…)

Being also a D700 shooter, some hints…

Yep. I took thousands of macro shoots with this reflex.
Never had any problem so far in 10 years of everyday very intense use.

At work we are saving money for purchasing a Nikon D850 in the near future. Luckilly, its price has dropped a bit lately. Later on, we hope to buy a new macro lens: so far I have been using a macro lens Nikkor 60 mm - f 2.8, which has served me extremely well too.

I am a bit worried about the size of the Raw files produced by the Nikon D850 and I do hope RawTherapee is going to handle them gracefully (together with a beefy computer of course…).
Luckilly, I alwasy shoot my plants diseases subjects with a tripod otherwise I would be also in trouble with such a big sensor as regards the sharpness side:-)

If you don’t need AF, go for a Apo-Rodagon lens. They almost have no CA. Have a look at this one I took with my D700 using an Apo-Rodagon 4.0/105 mm lens:
http://rawtherapee.com/shared/test_images/yellow_poppy.nef

I shoot a D850, and with a decent computer, you’ll be fine. If you get a new computer for it, look at the AMD Threadripper… All those cores!

Hello @heckflosse,

If you don’t need AF, go for a Apo-Rodagon lens.

Thanks. Never used the AF so far with my macro plants subjects :slight_smile:
As a plant pathologist, I mostly take pictures of fungi and bacteria samples.
When are savings are enough, I suppose I am going to opt for a macro lens in the 50-60 mm range. It is not necessary to have it internally stabilized because I always shoot with a tripod in our laboratory.

Hello @sguyader

I’m also a plant pathologist, so if you can share photos of diseased leaves, maybe as a Play Raw, I’ll be on it!

It would be fun indeed but I do fear we are going to “scare” the photographers of this forum with our pictures of very diseased leaves :slight_smile:

Joking aside, here is a picture of a bacterium, on Pepper leaves, quite common in Northern Italy, that is Xanthomonas vesicatoria (leaves + gyca and csga petri dishes with the bacterium at 2 days of growth) :

Here is the NEF raw file in case you are interested:

Thanks! I’m more mycologist and virologist than a bacteriologist.
What is the white stuff in the right petri dish? Paper?

How do you cope with changes in environmental light in your photo setup? Do you fix aperture/shutter speed/ISO?

I am a scientist myself and work with images mainly in high-resolution microscopy.
If I don’t photograph professionally, I do so only from the “artistic” aspect, the accuracy of the reproduction plays hardly any role for me.
The possibilities of post-processing in digital photography make it very difficult for me to find the boundary between necessary improvement and unwanted change of “reality”.
Nevertheless, I would like to show a technique that I sometimes use to “sharpen” and make fine details more visible.
However, this use of tone mapping is not really suitable for scientific photography.

Only one color cuvre in darktable plus (right) and minus (left) tone mapping.


LIZARD_SHARPENING-TEST.NEF.xmp (2.4 KB)

@Silvio_Grosso It depends on what the objective is for sharpening and what you expect from it. E.g., you have noted that

Are you intending to sharpen the unfocused areas so that they are more alike the more focused ones?

Taking @heckflosse processing as a base (really impressive in itself) , maybe you can further improve the look of your subject with wavelets:



LIZARD_SHARPENING-dc wv.png.out.pp3 (11.2 KB)

And you can always control the final sharpening with the global wavelets strength (if it looks oversharpened).

About the end of the tail, I’m afraid there’s no way to recover really unfocused areas, sorry.

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Hello @afre

Are you intending to sharpen the unfocused areas so that they are more alike the more focused ones?

Nope, my note about the tail not being completely in focus was just a casual remark.
Actually, I took many pictures of this lizard and one of them it appears most suited to make some experiment about sharpening.

Here it is (jpeg very compressed to post here):

Here is the NEF file (Nikon D700) in case you are interested:

BTW, let me ask you a question since you are extremely knowledgeable about G’MIC :slight_smile:
Can you suggest some unusual G’MIC filter in this domain to try in order to sharpen these pictures of mine?
At present, there are tons of them for this particular purpose, with little documentation, shipped with G’MIC and I am a bit lost…

@Silvio_Grosso, Here is a bright version. Tried to make the paper white and the lizard less dark. Are the colours right? Cropped to make it photographically interesting (for me, of course).
LIZARD_SHARPENING-TEST.jpg.out.pp3 (11.9 KB)