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capture one is just an instable software

carstenw

Active member
Yeah, mathematicians expect a certain amount of logic in the world :)

I also have a bachelor of mathematics, with a minor in computer science, and after reading this discussion, I feel like pulling out my math books again and running a few formulas off on paper :)
 
O

Odry

Guest
I know that all images need to be sharpened somewhat straight out of the camera and that LR2 has default capture sharpening settings, but I am trying to understand why the default settings need to be adjusted and how capture sharpening fits into the workflow. Ive read the Kelby and Evening chapters on sharpening in LR2, and have the MR/JS series on the Fine Print. What I think I understand is that the amount of sharpening is output dependent. So unless I am creating a slide show to be viewed on my computer screen, why would I be concerned with capture sharpening? Assuming for example that my only output is prints, why wouldnt I sharpen only once during the printing process?

Thanks for your help.
 

Bob

Administrator
Staff member
There are two stages of sharpening plus there is also usage of sharpening tools for other creative purposes.

1. Input sharpening.
Digital sensors are actually an array of cells which sample the light impinging on them (lets for a moment neglect bayer and other color formation related issues). In front of the actual sensor cell there sits a number of layers, some of which are part of the sensor itself. Some of these are built into the chip, such as the color filters and oxide, and passivation layers deposited on the silicon as part of sensor manufacturing. Others are assembled as part of the unit installed in the camera, perhaps a low-pass (AA) filter, and maybe a protective glass sheet. All of these impart blur to a greater or lesser degree.
Lenses also impart blur and veiling flare. Not only glass imperfections, but internal reflections, not to mention reflections that come off the sensor, hit the rear element or some other surface where a refractive index change might occur, and are returned to the sensor.
De-bayering and noise reduction also impart blur and color smearing.
The purpose if input sharpening is to reduce the visible effects of all the above.
One component is to increase the pixel-to-pixel contrast One way to do this is through the use of unsharp mask with a low radius setting (usually less than a pixel). The other component is to combat veiling. Sometimes this is done with unsharp mask with a low percentage large radius setting. The "clarity" slider of many converters is often implemented this way.

Of course there are other techniques (such as deconvolution LOL), but these steps are all designed to produce an image that is apparently free of these blurring and veiling artifacts.

2. Output sharpening
Each step in the image reproduction process introduces some sort of edge blurring effect. Inkjet printers effectively paint the image on paper with nano-sprayguns. Printing processes, no matter what technology used so far do their bit to fuzz things up. So the purpose of output sharpening is to attempt to compensate. Output sharpening is dependent on issues such as the reproduction technology, image size, and viewing distance.
Since each time an image is printed it needs to be sharpened appropriately for the specific purpose, it is left to the end as well as other compensatory adjustments such as curves and white-point and black-point compensation.

Separating sharpening into two stages enables one to standardize the process to some degree. Each camera and lens combination (and sometimes shooting situation) might need different treatment, whereas each printer/paper/size/distance combination another. If the steps are combined, then one is faced with an experimental trial and error situation which may waste both time and materials.
-bob
 

KETCH ROSSI

New member
Ketch, C1 image temporarily blurs as it's changing adjustments, and lets you know it's done when it snaps back to focus.
Thanks Jack to clarify that for me, sure wish I could see changes on real time to better get a filling of what I was doing.

Also Ketch may want to set your previews at like 1200 in the preference panel. i found that to be a good balance between speed and quality of preview.
Thanks Guy, done that now, and do see a marginal change on effect and duration of the blur, not sure what was this setting prior to changing it to 1200, but this does help a little, very little :) I just wish all changes were real time, and for a moment was worrying it was my system.
 
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