Sharpening: CaptureOne 9 or 3rd Party Software

[ErikKaffehr]

Hi,

Aliasing occurs when the lens provides detail the sensor cannot resolve. In this case the sensor will produce fake detail. Bayer sensors will have different sampling points for blue, red and green so these artefacts will be colorful. Sensors like Foevon will also create artefacts, but these will be monochrome as all colours share the same sampling points and density. So, Foevon will also induce artefacts, it is just that it is not very obvious.

The only solution to this problem is increase the resolution of the sensor beyond the resolution of the lens. A more proper way to say the same thing would be to reduce MTF at the Nyquist limit to reasonably small values. In well designed systems a Low Pass (LP)  filter does that job. In optical systems that is called an optical low pass filter (OLP). OLP filters are expensive and probably even more expensive in large sizes. Mamiya ZD had an optional OLP filter, at a cost of around 3000 $US. An OLP filter will affect all frequencies, so an OLP filtered image will need more sharpening.

Stopping down to small apertures will act as a low pass filter, due to diffraction, but diffraction will probably degrade sharpness more than a properly designed OLP filter.

The best solution is really to reduce pixel size. With the best lenses we have today, like the Otus lenses from Zeiss, we probably need something like 2.5 micron pixels to eliminate aliasing.

Check this example, shot on a 3.8 micron pitch camera:

The strains of the feather are quite credible. Note that the strains are not continuous. That essentially is an indisputable indication that some detail is fake, but it is hard to tell real or fake detail apart.


This image was shot on a 6.8 micron pitch sensor, and enlarged to the same size than the previous one.


Note that the feather shows a cross hatch pattern. That pattern is obviously a sampling artefact.

Best regards
Erik

Ps. I have been told that these images are school book examples of aliasing, but I have also gotten some nearly hateful comments. I hope that some folks on LuLa have grown up to accept that there are folks on the net who don't share their views and know a few things they don't.

Thank you very very much.

on a tangent, I really only shoot non-AA equipped cameras (Ricoh GR, D810, Sigma Merrill series). That said, I'm curious about you comment "non-AA filtered input (like from Medium Format cameras), there is traditionally not that much one can safely do." Do you mean this mathematically (image needs to be blurred by AA or motion or defraction) to benefit from deconvolution or any form of sharpening in general?

[Bart_van_der_Wolf]

Thank you very very much.

on a tangent, I really only shoot non-AA equipped cameras (Ricoh GR, D810, Sigma Merrill series). That said, I'm curious about you comment "non-AA filtered input (like from Medium Format cameras), there is traditionally not that much one can safely do." Do you mean this mathematically (image needs to be blurred by AA or motion or defraction) to benefit from deconvolution or any form of sharpening in general?

Yes, (from a Digital Signal Processing (DSP) point of view) ideally we start with a properly low-pass filtered image, but that's easier said than done. Our sensels are still relatively large (so projected detail will be smaller, too small to resolve, thus leading to aliasing), and for very high resolution or large output we often need to magnify enough to easily see the limitations/artifacts. For lower resolution output (most displays), and smaller output sizes, we can often down-sample, or physically minimize, enough to hide some of the artifacts.

Cheers,
Bart

[FrankStark]

Having followed this thread  as a relative beginner,  I have a couple of more mundane questions, if I may

I use Capture One 9, and do not have PS on my system. Nor do I have LR except v 5 on one of my computers. What do you use as a host for Focus Magic? I considered installing PhotoLine for that purpose but it seems a complicated work flow.

How do you use Focus Magic for pre-sharpening? Do you sharpen with it before "ingesting" it into CO? 

I have set up Fusion Express for access from CO. What is the difference between Topaz Infocus and Detail, and why do you prefer the later.

Lots to learn at this basic level.

Thanks

F.

[N80]

I would also like to piggy-back a question here. I did not see much mention of Nik Sharper Pro 3. Of course it is a bit old, but it is free, it was well reviewed when it came out, it allows local sharpening as well as layers and is designed specifically designed for output sharpening.

I have it but have not used it.

Just wondering how it rates as a step in the CO output process........given the fact that is completely FREE?

[Bart_van_der_Wolf]

Having followed this thread  as a relative beginner,  I have a couple of more mundane questions, if I may

I use Capture One 9, and do not have PS on my system. Nor do I have LR except v 5 on one of my computers. What do you use as a host for Focus Magic? I considered installing PhotoLine for that purpose but it seems a complicated work flow.

Hi Frank,

FocusMagic is basically a Photoshop type of plugin, so it needs a host program that can use the .8bf file extension plugins. Besides Photoshop, Photoline indeed also supports the FocusMagic plugin.

How do you use Focus Magic for pre-sharpening? Do you sharpen with it before "ingesting" it into CO?

FocusMagic is primarily intended as a Capture Sharpening tool, so it works best on unsharpened input, usually TIFFs. Capture One is basically a Raw converter that outputs TIFFs and JPEGs. It is possible to send the (TIFF) output to an external program for further editing (if CO sharpening is disabled, amount 0), but it cannot be sent to FocusMagic without a host application to run that. After editing/FocusMagic sharpening, the result can be re-opened into CO if one wishes so, but that's not how I use CO.

I have set up Fusion Express for access from CO.

Yes, that will function as a host for accessing the Topaz Plugins that are not (yet) stand-alone applications.

What is the difference between Topaz Infocus and Detail, and why do you prefer the later.

Topaz InFocus has only one purpose, Capture Sharpening of blurred input. You could consider it as the single Topaz Detail slider (also does Deconvolution sharpening), but on steroids.
Topaz Detail takes that sharpened output another step further towards output. It can be considered as a Creative Sharpening tool, and an Output Sharpening tool.

I use both FocusMagic or InFocus for Capture sharpening, but FocusMagic more often because it's less likely to create sharpening artifacts. Those artifacts can be avoided by InFocus, but that takes a lot more work. Sometimes Infocus does a better sharpening job, but that's not too often.

Cheers,
Bart

[FrankStark]

Thank you.  Since you said you sharpen at the end of your workflow, it would seem you use Focus Magic after CO, not before, and then use Detail after that.  I tried Detail and it seems very useful.

F.

[Bart_van_der_Wolf]

Thank you.  Since you said you sharpen at the end of your workflow, it would seem you use Focus Magic after CO, not before, and then use Detail after that.  I tried Detail and it seems very useful.

Yes, from CO, I export my Raw converted TIFFs without sharpening (select that option in the output recipe), and the first thing I do in Photoshop is make a sharpening layer on which FocusMagic is applied, then do other processing such as Clarity, then apply Detail.

Cheers,
Bart

[FrankStark]

Thanks again. I can see how the process is aimed at printing in Photoshop at the end (or some other use). Have been trying to avoid using Photoshop, but may have to if I want to use Focus Magic and use Photo Shops soft proofing capacities at the same time.

But one link in the chain at a time. Thanks for your response about sharpening.

F.

[alain]

FocusMagic is primarily intended as a Capture Sharpening tool, so it works best on unsharpened input, usually TIFFs. Capture One is basically a Raw converter that outputs TIFFs and JPEGs. It is possible to send the (TIFF) output to an external program for further editing (if CO sharpening is disabled, amount 0), but it cannot be sent to FocusMagic without a host application to run that. After editing/FocusMagic sharpening, the result can be re-opened into CO if one wishes so, but that's not how I use CO.

Topaz InFocus has only one purpose, Capture Sharpening of blurred input. You could consider it as the single Topaz Detail slider (also does Deconvolution sharpening), but on steroids.
Topaz Detail takes that sharpened output another step further towards output. It can be considered as a Creative Sharpening tool, and an Output Sharpening tool.

Cheers,
Bart

Bart is it possible and useful to make the output application ("photoline or other or even imagemagick") open, do the capture sharpening with default settings, save and close?
In other words to replace the CO capture sharpening with an automatic sharpening (of course for one camera).

Is it worthwhile for a D810 which has no AA filter?

Alain

[Bart_van_der_Wolf]

Bart is it possible and useful to make the output application ("photoline or other or even imagemagick") open, do the capture sharpening with default settings, save and close?
In other words to replace the CO capture sharpening with an automatic sharpening (of course for one camera).

Capture One can be setup to execute an application, such as Photoline, that acts as a host for Photoshop Plugins. I'm not aware of Photoline having a command line interface option that would allow to only run a single filter and then save, but maybe their forum has addressed such a functionality in the past?

There seems to be a xxPhotoshop (Plugin) host application, but I have no idea if that works as suggested for FocusMagic.

Alternatively you could try running a droplet that's based on a Photoshop action that runs FocusMagic. Haven't tried it myself.

ImageMagick can be run through a Batchfile that's called from CO, but I don't think it runs Photoshop plugins, so you'd have to program something yourself with an ImageMagick commands script.

And there is always an option to use Topaz InFocus which is accessible through its free host program, and can be called by CO.

Is it worthwhile for a D810 which has no AA filter?

In general, discretely sampled images that have not been pre-filtered, can cause all sorts of issues when sharpening is applied. A lot depends on image content. It would also depend on the lens used, and the settings (aperture, defocus).

Cheers,
Bart

[FrankStark]

By using PhotoLine as a dummy application, as one would use Focus Express, I find that with Edit with in C1, and then PhotoLine, then Filters, and then Focus Magic as a plugin; and if I make adjustments, let Focus Magic do its thing, then save the file, the resulting edited Tif shows up in my C1 catalogue. Since I can do the same for Topaz Detail (etc) after that, iit seems that I can so all my operations within C1 and its catalogue. I think. If this is true, having sharpened already, perhaps I don't need to check the no sharpening box in the process recipe when I process the Tiff. (or a JPEG output).

F. 

[sjprg]

For sharpening you might try Piccure+ for batching or Franzis's Sharpen for individual images. I like the results but make your own decisions.
10/7/16 Sharpen has just been updated.

[John Hollenberg]

Topaz Detail takes that sharpened output another step further towards output. It can be considered as a Creative Sharpening tool, and an Output Sharpening tool.

Bart,

After using LR for a number of years I have developed a renewed interest in Capture One.  I have 9.3 and Focus Magic already which I can use in Photoshop.  I downloaded the trial of Topaz Detail and am impressed after an initial look.  My question: how do you determine how much sharpening to use for output sharpening?  Do you resize the image first (I have a Canon ipf6300 which does better with 600 PPI input)?  I am used to just selecting sharpen for print in LR and getting (fairly) good results, looking for some general guidelines on the use of Topaz Detail.

Thanks.

[uptownguydenver]

Thank you very much for the tip. Will be vey useful.

[ErikKaffehr]

Hi,

As long as the lens outresolves the sensor, or to be more correct, has significant MTF at Nyquist the sampling will create artefacts, that is fake detail.

One way to see it, the high frequency detail that the sensor cannot be resolved will be shown as lower frequency artefacts. For some reason, these artefacts are not very obvious as long as they are monochrome.

The OLP filter is intended to reduce fine detail contrast at the pixel level to say 15%, that is not enough to suppress aliasing fully, but it reduces colour aliasing significantly.

Bart has some fine sense of sharpening. Personally, I have found that exporting with no sharpening and applying FocusMagic at default settings gives near optimal sharpening.

CO delivers cleaner image from demosaic than Lightroom, so that can be an advantage.

Sharpening should not be overdone...

Best regards
Erik

Thank you very very much.

on a tangent, I really only shoot non-AA equipped cameras (Ricoh GR, D810, Sigma Merrill series). That said, I'm curious about you comment "non-AA filtered input (like from Medium Format cameras), there is traditionally not that much one can safely do." Do you mean this mathematically (image needs to be blurred by AA or motion or defraction) to benefit from deconvolution or any form of sharpening in general?

[Bart_van_der_Wolf]

Bart,

After using LR for a number of years I have developed a renewed interest in Capture One.  I have 9.3 and Focus Magic already which I can use in Photoshop.  I downloaded the trial of Topaz Detail and am impressed after an initial look.  My question: how do you determine how much sharpening to use for output sharpening?

Hi John,

Sorry for not answering sooner, this message got swamped by other work.

It's difficult to say 'how much' sharpening to use, but it helps to start with a 'proper' amount. Proper meaning that no visible artifacts should be introduced. Then, depending out output conditions, one can add a bit more if it won't hurt the image at the intended viewing distance.

The difficulty with Topaz Detail is, that there are hardly any artifacts, so it's more up to the subject matter and taste of the photographer. One would e.g. usually not over-emphasize detail on a portrait of a baby or most women, but a macro shot of a flower or insect may need a boost to unveil tiny detail.

Thr Deblur control of 'Detail' is basically a much simplified version of Topaz Focus at a small radius. It applies Deconvolution sharpening, which may produce ringing artifacts if the radius becomes too large. So I tend to use that at the milder settings. Zooming in on the best focused parts of the image helps to see the artifacts, and stop just short of them developing, and use som artifact suppression to find a balance.

But the other controls have much more overall visual impact, so that's where the personal taste gets in.

I tend to use a trick to see which specific detail is affected most to achieve my previsualized goal. Just put all three levels of detail at their minimum (see attached tip 1), and then only play with a single one of them in turn (see attached tip 2a) to isolate the parts of the image that are affected. If those are the parts that help the image to improve, then that's what to focus on. Again, the 'amount' is a matter of taste, but subtle always works. If the 'Small Details' control produces too much detail in smooth gradients or emphasizes noise in the sky, just use a bit of negative boost (see attached tip 2b), or use masking.

Do you resize the image first (I have a Canon ipf6300 which does better with 600 PPI input)?  I am used to just selecting sharpen for print in LR and getting (fairly) good results, looking for some general guidelines on the use of Topaz Detail.

I do two things. At the native image size, I do the normal 'Creative sharpening' with 'Detail' (the Deblur control could be used as Capture sharpening, although I prefer FocusMagic if I have additional postprocessing to do). After upsampling to 600 PPI you basically only need to tackle some of the upsampling blur, and the Deblur control does a good job there. You can add an amount of Small Detail if the output medium loses too much punch due to ink diffusion, or if it could use some help in providing a more tactile aspect to image detail.

Minor artifacts that develop at 600 PPI will be virtually invisible at normal viewing distances. Because large format output at 600 PPI is probably upsampled, the Small Details control will be more effective in squeezing out every last bit of detail, and it will help in maintaining a good micro-contrast when people move in closer for inspection (the image remains more consistently sharp regardless of viewing distance).

So 'Deblur' and 'Small Details' are very useful for upsampled output sharpening.

Hope that helps.

Cheers,
Bart

[John Hollenberg]

Bart,

Thanks for the detailed reply.  Should be very helpful.

John