Varis PhotoMedia Tutorials

Transcription

1 Varis PhotoMedia Tutorials 2003, Lee Varis Welcome This tutorial has been prepared for the photographer who is striving to learn digital imaging. I make an effort to supply current information about digital imaging techniques and general information about computer technology that is pertinent for today s professional photographer. This information is based on my personal experience down in the trenches at the front lines of the digital revolution that is sweeping the photographic industry. One thing is certain: all of the information contained herein will be obsolete in a fairly short time - how short, I can t say. Be forewarned that things are changing very rapidly and the only way to stay competitive is to keep learning. I devote a good percentage of my time learning new things and I am attempting to share what I learn with you but this information will go out of date so you should be flexible and not take this tutorial to be the ultimate statement on the subject. I consider the knowledge contained in any of my tutorials to be public domain but the form in which this knowledge is presented is copyrighted as are all the photographic images used as examples. Unless otherwise noted all imagery is copyrighted by Lee Varis and any use of these images without permission is forbidden. You are permitted to use this tutorial for your personal education - you are not permitted to sell or otherwise distribute this material. Please contact me for any other use. I maintain a web site where I post additional information, examples and tutorials. You are invited to browse various portfolios as well as download free material and purchase additional tutorials at: I hope you find the information contained in this tutorial helpful. Please let me know if you find any errors or omissions - I m always trying to improve these materials! You may contact me via at: varis@varis.com best regards, Lee Varis 2003

2 The Art of Sharpening Final Finesse for Maximum Image Quality and Visual Impact All digital images require some level of sharpening whether they be scans from film or direct digital captures from a digital camera. Often, some sharpening is applied automatically by the scanning software or in-camera processing. Most photographers tend to ignore sharpening or, at best, treat it as an afterthought, applied as some kind of default setting low, medium or high based on subject matter or camera model. After all, if the photographer s done his job, his images shouldn t need too much sharpening - right? Sharpening is an art in itself. Good sharpening techniques can enhance almost any image and elevate the ordinary photo to an arresting image that jumps off the page. Really sharp images have a three dimensional quality that is almost impossible to achieve without using some kind of edge enhancing technique. Sharpening techniques were employed by the old master painters of the Renaissance by placing dark lines next to light edge highlights to visually carve important detail into an image. Today we use unsharp mask, a technique pioneered by astro-photographers whereby a blurred negative was sandwiched with a positive to enhance edge details in images of distant galaxies. Although the modern version of this technique involves complex digital image processing algorithms the principle is the same. We will examine a couple of the best Photoshop sharpening techniques in the following pages. This tutorial is by no means comprehensive, merely a good introduction to the best basic techniques useful with RGB images. There are many good techniques that require the black channel of CMYK for the best effect... these will have to wait for another tutorial. A thorough understanding of the following basic techniques will get you quite far however and you may not need much more for 90% of your work. You also will not need to purchase special plug-ins or actions once you understand these techniques. Lets start getting sharp...

3 Set Up Sharpening Lets set up a basic sharpening routine... We will use Unsharp Mask rather than Sharpen, Sharpen More or Sharpen Edges because it is the only sharpen filter in Photoshop s set that has any useful adjustable parameters. Most beginners simple run the filter directly on the image. Some experts advise you to convert the image to lab and sharpen the L channel. Others say just fade to luminance ( Edit- > Fade-> Unsharp Mask, choose luminosity in the dialog) right after running the filter. The best overall approach is to run your unsharp mask filter in a duplicate layer set to luminosity. This allows for the most interactive view of your sharpening effect. Before doing all that we should zoom to the best magnification to judge our sharpening effect. Zoom to 50% Many will advise you to look at the sharpen filter at 100% view - I used to do this myself. The effect of sharpening at this magnification will look at lot more drastic than it will look at the final printed size. The tendency, for most photographers especially, is to under sharpen because of this. When you are zoomed to 50% you are looking at the size of the image at aprox pixels per inch. Most of the time you are sharpening to size at 300 pixels per inch - by sharpening at the 150 ppi size you can compensate for the lower screen resolution of 72 ppi - the best compromise to view the intensity of the effect.

4 Make a Luminosity Layer Now that we are zoomed in properly, duplicate the image by dragging the background layer on top of the new layer icon at the bottom of the Layers palette. Change the layer apply mode to Luminosity by selecting from the drop down just below the Layers Tab. Now we will run the Unsharp Mask filter on the new layer. By running the filter on this luminosity layer we can avoid the colored halo effect that results from running Unsharp Mask directly on an RGB image. The saturated color edges are more noticeable in the printed image and this extra care can keep the sharpen effect from overpowering the image. Choose: Filter-> Sharpen-> Unsharp Mask... to bring up the Unsharp Mask dialog...

5 Anatomy of the Unsharp Mask Dialog Unsharp Mask works by enhancing the contrast of tonal transitions - we notice this as light and dark halos around edges. The sliders in the Unsharp Mask dialog give you some level of control over the size and intensity of these halos. The threshold slider determines the value change necessary before sharpening halos will be applied. This is primarily useful with images scanned from film due to the amount of grain visible in film images. Set a high enough number in the Threshold slider so that grain is not unduly enhanced. Don t be afraid to set the amount slider to a value over 100% Toggles the sharpen preview in the main image Zooms in or out on the dialog preview Sets the intensity of the sharpen halos Sets the width of the sharpen halos Sets the value change level that is required before sharpening will be applied The whole trick with using the Unsharp Mask filter is to set the radius and amount high enough to adequately sharpen without being obvious at the desired print size. You d be surprised at how much you can get away with - I almost always sharpen more than what I think looks good on screen.

6 no sharpening Blending Back normal See the dialog for this blending move on the next page... highlight blended A uniform level of sharpening everywhere in the image often looks unnatural. We can take advantage of various layer controls to blend sharpened areas back into unsharpened areas. In the image of the Jazz Guy the sharpened highlights on the trumpet look posterized - a little too crisp! The beautiful satin highlights can be restored by using the Blending Options available from the Layer options drop down at the upper right corner of the Layers palette. Here I choose to blend into the highlights of the underlying layer. Another application of this technique is with images that have shadow noise. It is easy to avoid enhancing the noise in the shadows by using Blending Options set the Blend-If sliders for the underlying image by pulling the black point to the right until the sharp noise is no longer visible.

7 When you select Blend Options you get the Layer Style dialog. What concerns us here is the Blend If section at the bottom of the dialog. To blend into highlights move the white slider to the left. To blend into shadows move the black slider to the right. Hold down the option/alt key to split the triangle slider in two this allows you to feather the transition from sharpened to unsharpened and blend the two layers better.

8 One problem that this image exhibits is that the edges where the figure transitions to the background have a very visible dark halo. When this happens against a light background as we see here the result looks unnatural lending a sort of cut out appearance. We can fix this easily because we have all the sharpening, and thus the dark halos, in the top layer. First make a selection for the figure. You can start with a loose lasso selection around the figure. Then use the magic wand to subtract the background from the selection (hold down option/alt while you click to subtract). Once you ve subtracted all the pieces of background around the figure you are left with a selection of just the figure. We will modify this to build a mask that subtracts the thin dark edge from all around the figure. Option/alt- click with the magic wand to subtract the background and get the selection to hug the figure.

9 Now all you need to do is click on the new mask icon at the bottom of the Layers palette a new layer mask is created from the modified selection. This mask will hide the dark halo edge revealing the original unsharpend edge from the layer below. Go to: Select-> Modify-> Contract... enter 2 pixels in the Contract By field the selection contracts just inside of the edge. Now do: Select-> Feather... and enter a value of 1 to soften the edge of the selection a bit.

10 Original Full Sharpening With Edge Mask The difference between full sharpening and the edge masked sharpen might not be very visible on screen but it will make a difference in print. Eliminating the dark edges next to the white background prevents the image from looking cut out and makes the sharpening look more natural.

11 High Pass Sharpen Layer This next technique is an alternative layer sharpen method that doesn t use Unsharp Mask! While not exactly identical to the results from running the unsharp mask filter it does have some subtle controls for adjusting the intensity of light and dark edge halos independently of each other. We start the same way zoom in to 50%, make a duplicate layer of the background. Don t change the Layer apply mode just yet though... Click to Final Version

12 First, de-saturate the new top layer: Image-> Adjustments-> Hue/ Saturation... drag the saturation slider all the way to the left. This will turn the image into a monochrome gray. We are eventually going to change the layer apply mode to Overlay but for the moment leave the apply drop down alone. Instead go to: Filter-> Other-> High Pass.. Enter a value of 1.5 (this will end up looking like a radius 1.5 in the Unsharp Mask dialog). The image will fade to a medium gray with subtle detail visible only in areas of fast tonal transition - anywhere the transition occurs in less than 1.5 pixels. Run this on a film scan and you might only be able to see the grain adjust the radius until you can see image edge details.

13 We can emphasize these details by using curves to build contrast into the gray image. Select: Image-> Adjustments-> Curves... Click on the center point in the straight line before shaping the curve. This curve will control how light or dark the halos around the edges are. In this image I d like to emphasize the dark halos more. Make the curve much steeper on the shadow side of the mid point. The highlight side should ramp more gradually as it gets lighter. This will make the dark details in the High Pass image darker than the light details. Once you ve adjusted the contrast of the High Pass layer change the apply drop down from Normal to Overlay...

14 As soon as you change the apply mode to Overlay you will see the sharpen effect. This works because anything that is medium gray in the Overlay layer will have no affect on the underlying image. The dark details in the Overlay layer will make thew underlying image darker - this creates the crisp dark edges in the eye lashes and hair! Unfortunately it is also over emphasizing the texture of her skin. It will be hard to protect the skin enough with a Blending Options adjustment so we will use another approach. Click to Original Version Click to Final Version With the overlay layer still selected, hold down the option/alt key and click on the new layer icon at the bottom of the Layers palette. This will create a black layer mask hiding all of the High Pass sharpen layer. The next step is to Paint in the sharpening by apply white with a brush into the black layer mask...

15 Paint into areas that you wish to sharpen: eyes, eyebrows, lips and hair. This selective sharpening is most effective with portraits of women where we definitely don t want to sharpen skin and wrinkles. Paint with a low opacity to gradually build up sharpening in areas that do not require the heaviest effect. For extra intense sharpening you can duplicate the Overlay sharpen layer to give the image a double hit. You can also change the way you shape the contrast curve to emphasize highlights instead of shadows. Use a large radius in the initial High Pass filter to create a subtle embossed look or run a blur after you do the contrast move to soften halos there are many possible variations... Toggle to Original Version

16 Octave Sharpening The next technique outlined here allows for a more intense sharpening with less obvious halos. It involves applying varying levels of sharpening at different radius settings to gradually ramp the sharpen halos so that they don t have a uniform intensity as they approach an edge. It is easier to see this in action than it is to explain in so many words. My sample image here is from a session I did with swing dancers. Even though I was lighting with fast studio flash lighting there is some movement blur we ll try to overcome this using octave sharpening. We will start the same way we have will all the other examples. Zoom in to 50% to evaluate our sharpening. Next make a duplicate layer and change the apply mode to luminosity. Now we will make 3 additional duplicate layers... Click to final

17 The idea here is to apply progressively wider radius sharpening in successive layers with decreasing opacity. Wide radius sharpens get low layer opacity and as the sharpen halos get tighter opacity increases until the tightest halo is at 100%. This technique is particularly effective with digital camera files because they have very little noise. Low radius sharpen will normally intensify film grain so it is necessary to use a higher threshold setting when using this on film scans. Digital camera files can be sharpened much heavier without problems. We will start with the first duplicate layer and the tightest halo. Turn off the other duplicates above this layer by clicking on the eye icon to the left of the layer thumbnail. Make sure the apply mode is set to Luminosity and call up the Unsharp Mask filter. Set the amount to 500%, radius to 0.5, threshold to 0. This makes for a very small but intense halo which will increase sharpen but be almost imperceptible at print size. We will leave the opacity slider for this layer at 100%... We will apply wider radius sharpens to the other layers starting with the next layer up...

18 The next layer up gets an unsharp mask radius of 1 pixel but we reduce the opacity of the layer to 50%

19 The next layer gets a radius of 2 pixels with an opacity of 25%

20 The last layer gets an unsharp mask radius of 4 pixels but we reduce the opacity of the layer to 12.5% At this point we would normally be done but this particular image suffers from the same problem that the Jazz guy does. The dark edge halos are exposed against the white background lending a cut out appearance to the figures. We will need to use our layer mask trick (page 8 & 9) to trim off the edge. The problem is that now we have 4 layers to mask. There is a solution, however. We can use one mask to control all 4 layers if we put these layers into a Layer Set! Click to see trimmed edges

21 Start by linking all the sharpened layers click in the little well next to the eye icon for each layer. This results in a chain icon showing that this layer is linked to the selected layer. The screenshot below shows the Layers palette with layers 2.0, 1.0 & 0.5 linked to layer 4.0. clicking on any one of these layers will show the other layers linked to it. Once this is done select: New Set From Linked from the layer options menu at the upper right corner of the Layers palette. Name the new set sharpen, leave the Mode at Pass Through and the opacity at 100%. All the linked layers are now contained in a folder in the Layers palette. This sharpen folder can be treated like an individual layer by adding a layer mask to it. Before we do that follow the selection routine we used for the Jazz Guy on page 8 make a loose selection around the figures (or simply cmd/ctrl-a to select all) and subtract the white background from the selection with the magic wand tool (by option/alt-clicking).

22 As before, shrink the selection by going to the Select menu: Select-> Modify-> Contract... enter 2 pixels in the Contract By field the selection contracts just inside of the edge. Now do: Select-> Feather... and enter a value of 1 to soften the edge of the selection a bit. Once the new selection is in place, click on the layer mask icon at the bottom of the layers palette the selection is placed into a layer mask for the Sharpen set and the dark edges against the white background are trimmed back. Click to compare dark edges

23 Final Sharpen To really appreciate the effect of our sharpening you should print the images! It is often quite amazing how even a small amount of sharpening can enhance an image. Octave sharpening can really make an image pop off the page! Play with different radius settings sometimes extremely large radius settings can be used to give an image subtle 3-D shading. You can also get some interesting effects by combining sharpening with blur layers. Click to original

24 Split Sharpening Sometimes when we sharpen an image it is desirable to treat lighten halos differently that darken halos. Such is the case with this example. Aside from the skin tones, the majority of the tones are of a low value. We can put quite a bit of sparkle into this image by sharpening it but, ideally, we don t want to add too much darkening anywhere. The solution lies in creating two sharpen layers one for lighten halos and one for darken halos. Start by making two duplicate layers drag the background layer to the new layer icon at the bottom of the layers palette... change the apply mode for the new layers to Luminosity for now we will change this again later... Click to final

25 The idea here is to get most of the sharpening effect with lighten halos and only use darken halos to put back some contrast into dark edges. I want to use low radius/high amount sharpening for the light halos and high radius/ low amount for the dark halos. Turn off visibility for the top layer (click off the eye icon) and select the 2nd layer rename this Lighten. We are going to run the unsharp mask filter on this layer at a low radius/high amount.

26 The sharpen settings shown here put a lot of sparkle into the image. Again, the normal strategy for evaluating the effect of sharpening is to view the image at 50% magnification! We are using the threshold setting here to prevent too much speckling from showing up in the skin. At the moment we are looking at regular unsharp mask with Luminosity layer apply mode. To make this work properly we need to change the layer apply mode to lighten but we still need our sharpening to affect luminosity only! So... here s the trick... Immediately after running the unsharp mask filter select: Edit-> Fade Unsharp Mask... and change the Mode: drop down to Luminosity in the resulting Fade dialog. This accomplishes the same result as using the layer apply mode but it allows us to use a different apply mode in the layer...

27 Now we can change the layer apply mode to lighten. The effect is subtle but the skin texture is better and the dress is a little lighter. This lighten sharpen has a bit of a glow that needs to be controlled just a little bit. That s where a darken layer will come in...

28 Start by turning off visibility for the Lighten layer, then select the top layer, rename it Darken and run the unsharp mask filter. We ll leave the amount at 500% we will reduce the opacity for this layer to control the final amount, right now we want to be able to see the halos clearly. Aim for wide halos, push the threshold up to minimize the effect on texture, limiting it to major edge transitions...

29 Right after running the unsharp mask filter, select Fade Unsharp Mask... and change the mode to Luminosity. Now we can change the layer apply mode to darken...

30 Reduce the opacity of the layer...

31 Finally, turn on the visibility of the Lighten layer and evaluate the result. By separating the lighten halos from the darken halos we can combine different radius and amount settings and create more subtle sharpening effects. The wide darken halos here are used to put back a little contrast into dark areas that were lightened too much by the light halos from the Lighten layer. Almost all of the sharpening is provided by the Lighten layer. This keeps the dark image from getting darker overall.

32 Finished Image This split sharpening approach can be used in many different ways. Some images may require stronger Darken sharpening or different radius settings to achieve the best result. Don t forget to experiment with blending options as an additional level of control and take advantage of layer masks to isolate sharpening to specific areas that need it. Click to original

33 Conclusion Sharpening digital images is more of an art than a science. Almost any simple sharpening can help an image especially in print but true creative sharpening can put a final polish on a 2-D image that makes it seem more dimensional. Sharp images jump off the page. The methods outlined here are intended to give you a platform to take off from they are by no means a complete compendium of available techniques. That being said, the techniques outlined here should take care of 90% of the digital photographer s sharpening needs. The last 10% involves more complicated, trick techniques and other approaches more appropriate for prepress output. There are numerous third party products that automate some aspects of sharpening and may be helpful for convenience or productivity but for the most part you can get by without these extra applications and plug-ins. The one exception I might suggest, if you are so inclined, is the set of Photoshop Automate plug-ins from Pixel Genius called PhotoKit Sharpener this set of plug-ins represents a sophisticated sharpening workflow that encompasses capture, creative and output sharpening needs. You can find this excellent software at: The sharpening routines developed by the Pixel Genius team provide special benefits for those photographers still shooting film and its worth investigating just for this reason. BTW, I am not affiliated with Pixel Genius other than being a beta tester for their products. I get no compensation for recommending them I just feel that PhotoKit Sharpener is a worthwhile product

34 Download Sample Files Sample files for this tutorial are available for download. All images are copyrighted 2003 by Lee Varis unless otherwise noted. Use of these files is restricted to personal education in this tutorial - no other use is permited. By clicking the download button below you are agreeing to these terms. Download Files These files are compressed in a Binhex archive. To use these files you must first extract them from the archive using a file compression utility. You can download the excellent free Stuffit Expander utility from Aladin Software by clicking below: Stuffit Expander Choose your platform from the buttons at the top of the web page - Mac, Windows and Unix

35 Varis PhotoMedia Tutorials 2003, Lee Varis Thank you I hope you enjoyed this tutorial. The techniques outlined here represent just the tip of the iceberg. Photoshop is a very deep application - a person could spend years studying it and there will always be more to learn. If all this seems a little overwhelming, take a break, do what you feel comfortable doing in Photoshop and return to this tutorial again later on. Often, it takes several weeks for a particular technique to sink in so give it time. I have other tutorials available online (navigate to the methods section), some are free and some are available for a modest charge. See tutorials and some examples of my work at: There are many learning resourses available on the web - here are a few other sites with good information: main.html These last two links are typical of the majority of Photoshop tutorial sites - they are focused on cool graphics effects not photography. You might want to look over this material anyway - sometimes you can learn a lot about basic functions in Photoshop. I m always trying to improve these materials and I m always open to your feedback. You may contatct me via at: varis@varis.com best regards, Lee Varis 2003