Concert photography is arguably one of the most difficult and challenging areas of photography to work in, for a myriad of reasons.

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1 High Pass Sharpening for low light Concert Photography A cheapskate s guide to rescuing crappy images. Concert photography is arguably one of the most difficult and challenging areas of photography to work in, for a myriad of reasons. The main challenge is the quality and quantity of available light. You are rarely afforded the luxury of using flash and even when you are allowed, it tends to kill the atmosphere of the image. Your two worst enemies are movement blur (which can sometimes be used creatively) and digital noise. This noise can consist of luminance noise (the small white dots visible when you zoom in) or colour noise (small multi coloured speckles) Zoomed out, the images have a gritty appearance. Most noise resides in the blue channel, so altering or cooling the colour balance of an image can accentuate the noise. Increasing exposure on an underexposed image, especially in the shadow areas, will also accentuate the noise. Unless you have a bunch of fast prime lenses in your bag, you will be struggling to obtain a correct exposure under difficult lighting conditions without excessive movement blur or even camera shake. The usual solution, after setting your aperture as wide as possible, and shutter speed as slow as you can get away with without suffering movement blur, is to crank up the ISO setting. The ISO setting on a digital camera electronically amplifies the exposure, and any noise present. It can also generate noise of its own. Digital photographers often have to resort to software based noise reduction techniques to reduce image noise, which used excessively can give a plastic feel to an image, destroying precious detail and giving an un natural look. I have walked away from bar gigs without a single image I would be happy to show my clients or anyone else. As in all areas of photography, the rule is to only show your best work. You have to be very tough with yourself.

2 I can often take 300+ images at a concert, whittle these down to t approximately 30 images and if I m lucky, I will have a small s handful I would be happy to show in myy portfolio. Sometimes, none will make it to my portfolio. Most photographers will be aware of thee Rule of Thirds There is a further rule known as the Rulee of Turds if its crap, its crap delete it Once in a while, there will be an image that you know you should really delete, but you captured a special moment and you just can t let it go. In this worked example, I ve used an image of Willy, lead vocalist with Doors Alive, taken at the O2 Arena at Glasgow. I was already pushing my settings to the max on a Canon 1d Mk3: ISO6400, f2.8 and shutter speed at 1/15 th with the camera resting on the edge of the stage. Willy was lying on the floor, out of the lights on the dark floor. The image was bathed in a purple wash and any attempt to adjust the colour balance accentuated the noise. Here is the starting image in Lightroom: The noise is much more visible in the fulll size version, but can still s be seenn in the foreground floor area.

3 The noise problem with this image was predominantly luminance noise. You can see the small white dots in the following zoomedd portion of the image: Adobe Lightroom 4 introduced an excellent Luminance noise reduction panel which does a great job of reducing this type of noise without destroying too much detail, but I wass really pushing my luck with this image.

4 The following two examples show s the result with Lightrooms noise n reduction applied. I pushed the slider way past my normal limit and edge detail has started too suffer:

5 Zoomed in: The above zoomed portion off the image shows thatt Lightroom has cleaned a significant amount of luminance noise, but there is still noise evident in the image. Time to get the big guns out.

6 I moved the image into Adobe Photoshop to apply further noise reductionn using the Topaz noise reduction plugin. The Topaz plugin is a very sophisticatedd and cleverr application that gives you a great degree of fine control over the end result. The following two images show the results of the Topaz noise reduction: r

7 Zoomed in: You can see from the zoomed image above that Topaz has done an excellent job of further cleaning up the noise, most apparent in the black area. No more white luminance noise dots, but the image is starting to get veryy soft.

8 Enter the secret weapon: High Pass Sharpening What is high pass sharpening? The standard weapon in most photographers arsenal is Unsharp Mask sharpening. There are more sophisticated applications and plugins, but Unsharp Mask is the one built into Photoshop. Adobe Lightroom also has a very effective sharpening panel. The problem is, any attempt to sharpen an image with noise present will accentuate and sharpen the noise along with the detail. Attempts to sharpen an image that have had noise reduction techniques applied will pull some of the noise back noise that has already been pummelled from pillar to post. Things start to look a little strange. High pass sharpening uses a specially created layer in Photoshop to accentuate the edges and ignore the noisy areas. The following pages walk you through the process.

9 High Pass Sharpening using Adobee Photoshop With your image opened in Photoshop, duplicate the layer:

10 With the new duplicate layer selected, choose High Pass from the filter menu:

11 You will notice that your image (and the layer thumbnail) has now n becomee a mediumm grey image with edge detail visible. You will be presented with a dialogue box containing a Radius slider. s The trick is to adjust the slider to pick out as much edge detail as possible without accentuating any noise in the in betweenn detail areas. The numbers will vary from image to image, the sharper the edge detail inn the original image, and the less you will have to increase the value.

12 You may notice that the grey image has some colour in the edge detail. We need to de saturate the High Pass layer from the Adjustments Menu:

13 The image above is the de saturated High Pass layer. De saturating reduces some of the halo effect on the edges. At this stage you might be thinking to yourself How am I ever going g to sell a grey cartoon like this? The next stage is the magic pixie dust that pulls it all together.

14 It isn t really magic; all we need to do is change the layer: blending mode m of the grey High Pass I usually find that the Soft Light blending mode gives the mostt pleasing results. Hard Light will make the effect erm harder. Experiment with different blending modes until you get the result you aree pleased with. The technique works with Overlay, Soft Light and Hard Light blending modes. If the applied effect looks too heavy, youu can reducee the effectt by reducing the opacity slider of the hi pass layer (to the t right of the blending modes drop down menu on the Layers palette)

15 Get your head around layer masks and you can paint the noise reduction and high pass sharpening effects in and out selectively the sky is the limit, just use a little imagination! Here is the preliminary result of the noise reduction and high pass p sharpening applied: Here is a before and after zoom: Even at this small size, you can see the improvement in detail after a noise reduction, with no discernable difference in noise levels.

16 And finally, a furtherr polishing of the image using layer masking techniques to control varying degrees of noise reduction and high pass sharpening, some localisedd colour balance adjustments and a little tidying up with the cloning tool and content aware fill Here is the start point image again for comparison:

17 Summary If you are a pixel peeper, thiss techniquee is not for you. The Rule of Turds should always be applied wherever possible, but if your client particularly wants a specific image and you fluffed it, this technique may well save your ass. At worst, you will rescue at least a web size version of a binner. Stevee Perks 2010