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
Last night was a nostalgic trip down memory lane, with four of our members presenting a slide show taken before year 2000. Now we all remember sitting in a darkened living room showing your latest holiday slides to friends, and neighbours, that click and whir as the slides changed, the stuck slide, the one that was upside down, or back to front, and uncle Jim dozing on the settee! It wasn't quite like that for last night's presentation, Richard Hildred began the evening with some amazing images of railways from British Rail days, we might ride one of the preserved heritage lines, and see the gleaming clean steam engines pulling a line of carriages, Richard's images returned us to the reality of steam powered passenger and freight operations, with the dirt, the grit, and grime of daily steam running, this image captures the essence of steam hauled mixed goods traffic, Richard's slide was in colour, but renders better here in monochrome. Next up was Tony Gaskins, many of his slides featured his first trip to the Maasai Mara game reserve, and the Ngorongoro Crater, Tony also showed slides from his trip to Canada, his slides and narration made for a great presentation. This image of a mother elephant, and calf was taken in the Ngorongoro Crater. After the break, Chris Birchmore presented many images from the Lincolnshire area, some of the disused, and crumbling buildings in the images made interesting subjects for photography, I have used this image of Bolingbroke castle, and from this viewpoint the church is clearly visible in this image, compared with today where only the church tower is visible. Graham Harrison was our last presenter, last but not least, the variety of images shown was remarkable, several from Wales, and quite a few that had been entered into club competitions previously, and were of high quality, as this image of a Flamingo shows. It was a fascinating, and interesting evening, thanks to each of our presenters, and to Dave Mann for the refreshments.
Good Afternoon, All, Last week at the club we held our monthly print competition, with the categories of "Mono" and "Open", judged by Diane Seddon. It was a very good evening with Diane critiquing our prints with helpful comments on how we could improve our images as well as praise. The results are on our website but well done to David Whitehouse for best print in the mono and Dave Turner for best print in the open. This week, Wednesday 22nd October, we go back in time to before the millennium with transparency slides to be shown by Tony Gaskins, Chris Birchmore, Richard Hildred and myself. You can start sending Harry your entries for the PDI of the year, all the rules etc are on our website, but the important thing is you can enter any PDI's as long as they have never been in a PDI of the year before. There are six subjects and an overall max of six PDI's, no more than three per subject. Regards Graham
A print competition was held last night with the categories of; "Monochrome" and "Open". Diane Seddon from Cleethorpes Camera Club was the judge for the evening, Diane is very skilled, and thorough in her judging, providing useful insight, and critique of the prints. Many of her comments centered around the best cropping of an image to optimise the subject within the frame, and giving the subject "room to breathe" in the framing. Congratulations to David Whitehouse placed first in the "Monochrome" category, with his superb rendering of a face sculpture, and Dave Turner placed first in the "Open" category with his stunning print of the sunrise over Whitby Harbour. Thanks to Diane Seddon for a great evening, and as she remarked at the end of the competition all the prints were of an extremely high standard. The Competition Page has been updated with the highest placed images, but currently the score sheets for the competition are unavailable.
Good Morning All Last week Dave Bennett came to the club again, it has been a while since we have seen his photography but well worth the wait. Dave's photographs were excellent and his story telling along with AV's made it a very good night. This week, Wednesday 15th October, we are holding a print competition, with the categories of "Mono" and "Open", our judge for the evening will be Diane Seddon AFIAP CPAGB BPE3* she is well qualified to judge our prints. The following week we are going to try a retro night again, with Transparencies taken prior to the year 2000, please let me know if you want to take part and have a time slot allotted, time will depend on the numbers wanting to take part. Regards Graham
Last night Dave Bennett came to the club to show us AV's and narrate other sets of photographs on a theme. Dave started with photos along the Humber and then carried on the evening with AV's on nature, flowers and transport as well as talks and photographs showing us Grimsby docks including detailed photographs of fish smoking and engineering. Dave's photography is of a very high standard with strong colours, lot's of use of depth of field and they tell a story. A great night, thank you Dave.
Good Morning All Last week at the club we held a local PDI competition with a category of "5 Minutes From Your Home", we had some very good entries in each category with myself, and Dave Turner judging on the night. All the results are on our website, but well done to Derek for his mobile phone picture of a remembrance seat in Horncastle and Harry for his hellebores in the "Open" category. This week, Wednesday 8th October, Dave Bennett is coming to the club to show us what he has been taking lately, Dave does quite a bit of AV so as usual it will be a very good night. A reminder, send your print titles for the next print competition to Dave Turner by midnight Wednesday and bring your prints in this Wednesday night as well please. If you have any more N&EMPF Exhibition PDI entries send them to me by midnight tomorrow (Monday) please. Regards Graham
Our PDI "Local" competition was held last night, with the categories of "5 Minutes From Your Home", and "Open". Dave Turner, one of our members began the evening with judging the "Open" category, always a difficult category in my opinion because of the variety of subjects entered into the competition. Dave had previewed the images on his home computer, and had notes on each of the images, he provided excellent feedback on each image. After the break, Graham Harrison began judging the "5 Minutes From Your Home" category, this was a very unusual subject category which stretched the creative ingenuity of members, and it was particularly interesting to see what members had submitted. Graham judged the entries very fairly, and provided very good critique of the images. The standard of images submitted was high, which makes judging a competition such as this difficult, and as always is subjective, but a big thank you to both judges, it was an interesting evening. The first placed images, from each category are shown on this post, "At the Going Down of the Sun" by Derek Smith, "5 minutes from your home", and "Hellebores" by Harry Kerman in the "Open" category. The website Competition Page has been updated with the top three placed images, and the scoresheets.
Good Morning All Last week at the club member Tony Gaskins gave us an excellent presentation of his recent trip to Kenya on safari. Tony showed us the animals and birds he had encountered on his trip. It was an evening of excellent wildlife photography as well as a very informative talk, thank you Tony. There is also a report on our website blog. This week, Wednesday 1st October, we are holding a local PDI competition, with the subject categories of "5 Minutes From Your Home" and "Open", Dave Turner has kindly offered to judge the Open with myself the subject, and you have until midnight tonight to enter. Dave Turner is also asking members to send him the titles of their prints for the next print competition, the categories for this are "Mono" and "Open". Regards Graham
Our member, Tony Gaskins presented us with an illustrated talk on his visit to the Kenya game reserves last night. Tony's talk was perfectly timed, and his description of the trip held our attention throughout the evening, the images he captured were indeed stunning. The variety of wildlife he captured with his camera were amazing, all of the photos of birds were incredible, and the fact that they didn't fly off like they do here in the UK. On Lake Naivasha Tony captured a sequence of a fish eagle swooping down to catch a fish, just look at the way those deadly talons are outstretched to capture the fish. The lodge Tony stayed in at Tsavo West was beside a watering hole, look at this capture of a Kirk's Dik Dik, taken from the balcony of the lodge. Images of Hippopotamus, Lions, Impala, Ostrich, Giraffe and Zebra kept us enthralled through the evening. Thank you and well done Tony for an interesting evening.
Good Evening All A little late as just got back late this afternoon from the golfing trip, I didn't take my camera other than phone as I wouldn't have really had time but there was some interesting wildlife about including Swallowtail butterflies which was a first for me. Last week you had the monthly PDI competition, Long Exposures and Open, Derek has done a blog on our website and the competition page has all the results. Some excellent photography on show judging by the top places. This week, Wednesday 24th September, we have member Tony Gaskins entertaining us with one of his talks, Tony is well travelled so as usual it will be an excellent evening of photography. Regards Graham
