Sharpening
Paul Malley • 18 April 2022
SHARPENING
A few Blog entries back, I submitted a short piece of work regarding my use of 'Auto-ISO' which, I'm pleased to say, generated some interest and subsequent discussion at the Clubhouse. In a bid to keep alternative thoughts and views going, this time I'm including a section on my preferred method of Sharpening images (lights blue touch-paper and steps back...), - please note I said "my preferred method" as, not only are there a number of ways of sharpening an image, but it is one of the most 'Subjective' issues when concluding a workflow process.
Many DSLR units are fitted with an anti-aliasing filter in the sensor path, which counter affects the moiré patterning, or coloured cross parallax of some light wavelengths. Anything placed in front of the sensor, can optically reduce the efficiency of the light path so, to overcome this, a degree of sharpening of an image is required, to reinstate any corrective action. Newer DSLR and Mirrorless units do not all have this anti-aliasing filter, but sharpening is still applied within the workflow.
Sharpening works by producing a better defined line (NOT the same as contrast) at boundary edges, (in the good old wet darkroom, this was termed Acutance). The degree and method of sharpening as stated, is hugely subjective as, applied to the wrong style of image, or at the wrong focal viewpoint, or in too greater strength can be detrimental. I have seen the evolving of sharpening within 'Photoshop Elements' since about 2008, where it was issued as a simple one-click function under the 'Enhance' Tab as 'auto-sharpen'. This was a quick one-stop pass that applied sharpening via an algorithm which, although hit and miss at times, gave a somewhat credible change. In subsequent versions, it became more refined, and sliders were introduced, offering control into variable levels of overall sharpness. About 10yrs ago, a huge step-change came in whereby the edge radius and strength could be altered to suit, offering 0.1 pixel units. Nowadays, sharpening can be done on separate layers, combined with clarity, contrast and split down within different layers, even identifying selective target areas to sharpen, before they are all merged down like layers in a sandwich.
For me, in my current Affinity Photo Software, I use a 3-stage sharpening process (Please note there are differences at the final stage for presentation in Print format, or display as a PDI). I conduct each stage in isolation, and it is done as the final part of my jpeg workflow process before I save the image.
Stage 1. This is a PRE-SHARPEN action, where the minimal radius and strength factor are applied to the overall image via the strangely termed 'Unsharp Mask' (each part of the image gets the same sharpening factor in one operation).
Stage 2. This is CREATIVE or SELECTIVE Sharpening, where I can select/identify what part of the image I wish to enhance beyond Stage 1. It may be the model's eyes, a tree in a landscape, or a head-on motorcycle fairing. In this stage, using a New Layer, selecting a brush, I work round the item and check it is bounded by the infamous 'marching ants'. Once identified a second pass is given using the same as in Stage 1. Once completed, a simple deselect of the marching ants shows the added 'pop' of the detail within the selected area. I then Merge/Flatten the Layers into one.
Stage 3. The final action is termed OUTPUT Sharpening. For me, working in PDI, I resize the document to the longest 1920 x 1200 format and apply a final overall sharpen in Unsharp Mask at a low output. This third and final stage can be dramatic as it is at the output for a good projected resolution.
If all has worked well, the image should have a nice, overall sharpness courtesy of stages 1 and 3 and the main point which the viewer may concentrate or gravitate to should have that extra pop, courtesy of Stage 2.
As a small aside, I remove my Noise during RAW conversion, as you don't want to be working on a noise image, either by creating Layers and putting Noise on top of Noise, or sharpening Noise at three separate stages. Noise can also have the effect of apparent sharpness reduction, - so get rid of it early.
Be wary of over sharpening, it can lead to artefacts, jagged edges or fringing, in worse cases it can also promote haloing or banding separation. Sometimes, less is more and I usually 'back-off a bit' on my final sharpening, rather than push a sharpening boundary.
Have a try with small amounts of sharpening, on different Layers (always on a working copy file, not the original primary jpeg) and pick something out that you want the viewer to look at. I have done my 3-Stage approach on this image of the Kingfisher, with selective sharpening applied to the head and leading edge of the wing.
Louth Photographic Society
Good Morning All We had a really good week away last week in the Peak District, the good weather helped and we visited many places including Salford Quays and climbed to the top of Kinder Scout and Mam Tor. Last week at the club it looks like you were treated to some excellent coastal photography from member Tony Gaskins, Tony does a lot of long exposure photography producing stunning photographs. There is a report on our blog page with photographs from the evening. This week, Wednesday 15th April, is Derek's studio evening where we are invited to come along with our cameras, there is a £5 charge on the night to help pay towards the two models. The following week is a print competition, with the categories of "Circles" and "Open", you can send Dave Turner a list of your entries and bring your prints in next week. Today is the Foster Challenge at Nettleham village Hall, 1.30pm for 2pm, Louth has entered the competition as usual so it would be good to see a few members attending. Regards Graham
Our speaker last night was our very own member Tony Gaskins, who gave an excellent presentation "Coast 3" with some stunning visual images. Tony specialises in capturing long exposure coastal scenes, he related how beginning several years ago with a long exposure view of Whitby Pier he got the "bug" for long exposure photography. Much of his photography takes place along the Lincolnshire, and Yorkshire east coast, often arising in the early hours to catch a sunrise. Weather conditions dictate a lot of how the final image looks, and the long exposure style often creates a sense of calmness, and serenity, with pastel coloured skies, and milky seas. When the weather turns wild, the long exposure image presents a very dramatic scene with foreboding clouds. He recently travelled to Lewis & Harris island in the Outer Hebrides and took many images there, sometimes at sunny white sand beaches, and at other times moody bleak images as the weather closed in. Tony's technique requires a lot of patience, often spending hours at a location, with the camera mounted on a study tripod, and the ND filters on the camera permitting an exposure time of several minutes. Many thanks Tony for a very informative talk, well presented, and with some beautiful imagery.
Good Morning All Last week at the club we held a Local Nature and Open PDI competition, members Dave Turner and Steve Chapman kindly offered to judge the competition, thank you to you both, it was a good night and the entries were of a high standard giving you both quite a task. The results are on our website, but the two winners on the night were, Local Nature Tony Gaskins and Open Harry Kerman. This week, Wednesday 8th April, Tony Gaskins, one of our members is showing us Coast 3, a PDI presentation. Tony is an excellent photographer and spends many hours photographing our coastline. Aprils Print competition, Circles and Open is fast approaching, you can send your titles to Dave Turner when your ready and bring your prints in the week before the competition. Regards Graham
It was no April fools, when we held our PDI (Projected Digital Image) competition last night. The images submitted into this competition were off the highest quality. Dave Turner judged the Open category, which I think is always one of the hardest categories to judge, pitting landscapes, against nature, and still life, but Dave did a magnificent job, offering well founded critique of the images submitted. After the break, Steve Chapman judged the Local Nature category, (nature images taken within a 25 mile radius of St. James' church, Louth) Steve "held back" 10 out of the 18 submitted images, and gave those 10 images very careful consideration until he finally arrived at the 3 highest placed images. Steve commented that the submitted images were indeed of high quality, and he took his time to evaluate the submitted images and offered useful critique on each one. The competition made for a very interesting evening, and all members deserve praise for the quality of the submitted images. The website Competition page has been updated with the full results, and the top three images from each category. On this post is 1st placed Sedge Warbler, Cleethorpes by Tony Gaskins, in the Local Nature category, and 1st placed Hudson Bay Wolf, (Lincoln Zoo) by Harry Kerman, in the Open category.
Good Morning, All, Last week at the club member Chris Birchmore gave a presentation on MPP cameras which included some of Chris's collection of cameras and prints taken. There is a report on the evening on our blog page. Thank you Chris for an interesting evening. This week, Wednesday 1st April, we are holding a local and open PDI competition the local subject being nature, please if you haven't already, send your entries to Harry before midnight tonight. Members Steve Chapman and Dave Turner have volunteered to judge. Also on the Wednesday 1st April our Louth Photographic Society 70th anniversary exhibition will be open to view at the Louth Museum. Regards Graham
Chris Birchmore gave an informative, and interesting talk and demonstration of his medium format film cameras. at the beginning of the evening Chris gave a potted history of the origins of the MPP cameras he was showing us. The cameras take a 5 x 4" film stock, and looking at the cameras it seems incredible that photographers in the recent past could take excellent photographs with these. The MPP cameras were often used by the British Armed Forcies during the Second World War, and throughout the 1950s, and 60s, and some of these medium format were still being manufactured in the 1970s. The prints that Chris showed taken with these cameras were of excellent quality, with an amazing depth of field. Many thanks Chris for a fascinating evening.
Good Morning All Last week at the club we held a committee meeting, which was very productive, we made the final arrangements for the exhibition, charity night, and studio evening as well as other items on the agenda. We are holding an Exhibition opening night at Louth Museum on Friday 17th April celebrating 70 years of Louth Photographic Society. There will be a small buffet and cold drinks available, if any member would like to donate a bottle of wine to the occasion please hand it to Harry at one of our club nights. This week, Wednesday 25th March, member Chris Birchmore will be giving us a presentation. The following week is a local competition, with the categoriess of "Local Nature" (up to 25 miles radius from St James church) and "Open" (unlimited mileage) please send your entries to Harry before midnight, Sunday 29th March. Members Steve Chapman will judge the Nature category, and Dave Turner the Open category. Regards Graham
Good Morning All Last week at the club we held our monthly PDI competition judged by Martyn Wrigg, the standard of entries was very high and well done to Tony Gaskins for a first in the Architectural Detail and Derek Smith for his first place in the Open. All the results are on our website under competitions. This week, Wednesday 18th March we will be holding a Committee meeting, just committee members for this one. The following week Chris Birchmore is the speaker for the night. Harry is now accepting entries for the PDI local competition, with the categories of "Local Nature" and "Open". We judge this competition in house so if you would like to judge one of the subjects please let me know. Regards Graham
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A PDI (Projected Digital Image) competition was held last night with the categories of "Architectural Detail", and "Open". Martyn Wrigg was our judge for the evening, and he competently judged the submitted images, although he diid surprise with some of his choices of placing, but that's a judges perogative. Martyn complemented members on the quality of the images presented, which had made some of his decisions difficult. First placed was "It's a Fixer Upper" in the Architectural Detail section, and "Dervish Musician" in the Open section. Congratulations to Robin Begley, who as one of our newest members submitted some impressive images, achieving a 3rd place in "Architectural Details", and 2nd in the "Open" category. All the results are now posted to our website Competition page.
