Sharpening old files really can make a difference


(Ingo Weyrich) #1

Today I worked on some files of my old Nikon D200 and as I sharpened one of them I really was amazed what one can get out of this old raw files concerning details.

Left is unsharpened, right is sharpened. The history in left panel shows which settings I changed:


(Rick Scheibner) #2

It’s yet another reason to hang on to old RAW files.


(Stefan Chirila) #3

I have an old D200. I’mma put that bad boy to some use with my telephoto :open_mouth:


(Ingo Weyrich) #4

Be warned. The settings I used work really great for shots with my Nikkor AIS 2.8/24mm lens mounted to the D200 aperture set to 8. For different lenses/apertures on D200 you need to play with the RL denconvolution radius (mainly).


(Ingo Weyrich) #5

Btw: did anyone see the funny thing in this image? The irish crazyness?


(Sebastien Guyader) #6

Is that a “house” wit just 3 walls and no roof in the foreground?


(Ingo Weyrich) #7

Yes. The left (dark gray) has a roof but no windows, while the brighter one (right of the dark gray one) has no roof, but windows :slight_smile:


(Sebastien Guyader) #8

Maybe the one on the left is some sort of barn?


(Ingo Weyrich) #9

Yes. Same thought here. Though it still looks funny to have a house with windows but without roof.

Another funny one from an irish B&B (clean me mirror writing):


#10

Yes, looks better. As said before, I like interesting things like roofless or windowless buildings, and messages on windows. Makes life more interesting.

Actually, what bothered me were the sliders. Looking at them, the brain wobbles a bit deciding which are the main parameters. Perhaps, order them by their function, from parameters that directly relate to the sharpening algorithm first. What bothers me the most is the horizontal rule after Method; should probably be before it, as it doesn’t have anything to do with the contrast threshold or blur radius.


#11

Any advice on when to use RL deconvolution and when to use unsharp mask?


(Ingo Weyrich) #12

No, as I don’t use the unsharp mask.

For RL devonvolution the default radius of 0.75 often is a bit too high (though it fits perfectly for my Ais 2.8/24mm shots on D200). It also depends on the aperture of the shot. If you shot past diffraction limit, larger radius can get some details back without introducing artifacts.

But even when using only RL there is no general rule for the settings (though I only change radius and contrast threshold). There are files from sensors like Nikon D200 where quite large radius settings work fine, which could one let assume it’s because of the AA filter in the D200 and it’s quite low sensor resolution (10MP APS-C). On the other side the almost same settings also work fine on a modern camera even when using pixelshift. For example this screenshot shows a 100% crop from a Pentax K1 pixelshift file. Left without sharpening, right with RL deconvolution:

It also matters what you want to sharpen. I always sharpen for fine details in 100% view. Others sharpen for edges and so on…


#13

So you never use unsharp mask?


#14

I believe USM is more widely used than RL. Which one to use depends on the effect you desire. Also, different apps have different implementations, so always compare and contrast. Personally, I prefer RL. I suggest you read the following:


(Ingo Weyrich) #15

I wouldn’t say ‘never’ as I have to use it sometimes when an issue is reported where the pp3 uses an unsharp mask. For my files I never use it. But that absolutely does not mean, that unsharp mask is bad. It’s just, that I’m used to RL since some years and prefer it.


(Ingo Weyrich) #16

As RL is much slower than USM, an alternative worth to try (compared to RL radius 0.75 / 30 iterations) is USM with radius 0.43 and amount 1000…
Much faster than RL and concerning detail resolution very close


(JegMeg) #17

You made this thread some time ago.

Is it enough to use the method in this thread , or should I try to learn what was done in the other thread ?


(Ingo Weyrich) #18

The method in the thread you mentioned (My sharpening workflow) fits my sharpening workflow.
Other cameras/lenses may need a different workflow, though the basics (contrast threshold…) should not differ much


#19

According to the Wikipedia article on USM, it says that " For deconvolution to be effective, all variables in the image scene and capturing device need to be modeled, including aperture, focal length, distance to subject, lens, and media refractive indices and geometries.

Which values does RawTherapee use / need? Some of my photos are with manual lenses and can lack aperture data, and with manual zooms can even lack focal length data.


(Ingo Weyrich) #20

None, RT RL deconvolution just assumes gaussian blur.