A most compelling evening (well if you are a camera club member) had courtesy of Keynsham Photographic Centre. Simon and Neil took us through papers, sizes and types of processes KPC offer and their knowledge and enthusiasm went a long way to explaining why KPC is a destination of choice of so many serious photographers here-abouts. Around 2 in 3 of those present were already users but we all had something new to learn about the services they offer, which are quite extensive. I have always found them to be helpful and friendly and I am happy to pass on a recommendation to use them.
Why print? There is an emotional and a logical answer to this. The emotional one is that we do seem to react differently to a print than to a projected image or one on a phone or other screen. This is certainly the case with the written word. With pictures it might be an age thing, with those of us of a certain maturity having an emotional tie to what we started with, the family albums and so on, but as these are family history it is not uncertain that these emotions are passed on. It might be the way we view what is art. Even slides are, these days, often rendered digital. Prints have a longevity that digital files cannot match.
The logical one is more existential. Our photographs aren’t photographs until they are printed. They are computer files that are capable of being rendered as images given the right, seldom very cheap, equipment. To that extent they are, at best, semi permanent records. They exist not as pictures but as 1’s and 0’s and that makes them vulnerable to damage, loss and redundancy in many different ways.
One of the questions that came up in discussions was the notion of the minimum resolution (pixels per inch or PPI) as a ratio to print size that is compatible with a reasonable quality print. In order to look at this we need to look at and differentiate between two measurements that the computer file we turn into a picture holds – and which can be reset via (photo editing) software. The first is Pixels Per Inch and the second is Dots Per Inch, or as we will refer to them PPI and DPI.
There is a previous post dedicated to this and a good start if your interest is more than passing. Essentially the PPI is a measure of the resolution of the computer file when shown on a screen and the DPI a measure of the resolution that a printer will reproduce the computer file as a digital print. They are not the same thing, they are not interchangeable, the connection between them is that you cannot use DPI to overcome low resolution in the PPI. That might not seem like much of a connection but it is a common error, at least it is a common misunderstanding.
Just as one is not strictly reliant on another there is an optimum setting for both, but it is not a single magic number or formula. This is because different manufacturers of camera sensors and printers construct their wares in slightly different ways to slightly different priorities. The only rock solid constant you can apply is garbage in garbage out aka GIGO. What doesn’t help is that there are always going to be subjective elements to the ideas of output and acceptable, but we can set these aside.
A slight diversion, but one that is worth taking, is the purpose for which we are taking our images in the first place. The digital age has brought with it a number of outlets that, even 20 years ago, were pipedreams or even unimaginable to most photographers. Film cameras would enjoy their predominance for another 10 years in the “serious” and professional markets. A decent living could still be made from stock photography. These days there are far more outlets and they demand different things of the data files they publish. What remains is the fact that proper prior planning prevents poor photography. Start with the end in mind and choose formats etc accordingly.
The argument for recording images in camera RAW is that all the information is left in. The argument for JPEG is its universality and space saving compression. The fact is you can shoot in both and convert your final image from RAW to JPEG or any other format (has to be some other format as you cannot save in RAW). In your final version of the image is the information that other devices are going to use to present your image, including colour space, PPI and a whole lot else. The point here is that you are going to have to make, or let programme defaults make, these decisions to determine the look of your output (as best you can).
So, long way round to the answer we were looking for but the fact remains, that for all the reasons above, there simply is no answer to the question of a ratio of file resolution to print size because Pixels are not the same size on all cameras – 24 mega pixels on a 35mm sized sensor take up more space than 24 mega pixels on an APSC sensor. There are approximations, guidelines and above all, experience. Let’s look at rules of thumb, but first a caveat.
Pixel peaking, the urge to zoom to the maximum and suck the teeth at the lack of relative clarity, is neither helpful nor useful, outside of certain photographic publications desperate for some comparators in a world where you really have to go some to find a “bad” lens or sensor. It’s the aggregate of the pixels used that we view and a badly composed photograph is a badly composed photograph regardless of the amount of money you have spent or your equipment’s DXO rating. We are here looking at making a print of what you have got, regardless of your motive to print it.
Lets first talk of PPI. Smaller sized prints, say up to 10 x 8 (ish) we can get a reasonable print at 125 ppi. That is to say at arm’s length it’s going to look OK. Press your nose against it or use a magnifying glass it is going to look pretty rubbish. I have to say that such a view point rather spoils the whole point as, again you are looking at the aggregate of the pixels after all, or as I like to call it, “The picture”. This is a fall-back position only, If your default is 72ppi (i.e. it’s designed to show up on your computer or phone screen) then you are not going to get much above a 6 x 4, maybe 7 x 5 at a pinch, out of it (feel free to prove me wrong because you are only going to find out by using your combination of equipment and the printer you choose). The best lies between 200 and 300 ppi, by more or less common agreement. KPC ask for 305 PPI. Basically of you use the 300 end of the range you are likely to be close to the optimum for most commercial printers at standard sizes. Refer to your supplier for the necessary information. To change images PPI we use editing software like Lightroom, Gimp or Affinity.
But we were looking for a rule of thumb. Any minimum figure is a result of the combination of equipment particulars and specifications and materials used.
So, take the longest edge of the image (measured in pixels) and divide by the longest edge of the desired print size (measured in inches). If an image measures 3,840 x 5,760 pixels and you want an 8 x 10 inch print. 5,760 pixels ÷ 10 inches = 576 ppi. That’s more than enough resolution. If you want make a 30 x 20 inch poster out of that image, you’d have a resolution of 192 ppi (5,760 ÷ 30), which isn’t high enough for optimum, if we are looking at least at 200 PPI. This is a minimum remember, so adjust accordingly.
Alternatively, and my personal method, size the image in inches at a ratio of 1:1. So an 18 x 12 print is sized as an 18 x 12 image in my editing software (Gimp). The resolution is set at 305 by 305 dots per inch as I use KPC, and the image, in pixels, is 5490 x 4118. The down side is the file size, the upside is its going to fit without faffing around.
So http://www.keynshamphoto.co.uk/ and start printing!
Given the travails that we went through to get last meeting off the ground, loosing not one but two judges at very short notice, then Bristol traffic conspiring to wedge the prints in an immovable traffic jam on the other side of town, just when things looked like they might be going right leads one to wonder just what the universe was telling us. Absolute sterling work from the Competition Secretary, Mark O’Grady, frustrated by circumstance. Big thanks from all of us Mark, for going above and beyond. Then – and British readers of this blog will want to make sure that they are resolutely braced before taking this bit in – the tea urn went missing. Still we got somewhere in the end.
So, why does a club have competitions? There are, of course as many reasons for that as there are club members. Recognition, acclamation, ideas, feedback, discussion something to fill a hole in the calendar, are just a few of the headlines you could write a whole blog and more on each. No, don’t panic, I am not going to. When children draw they don’t have a concept of consequences, is this good or is this bad? Right colours? Does it look like it should? and so on. What they produce is intensely personal and very honest. As we grow older we learn notions of correctness and benefit and we unlearn the naiveté that made making pictures fun. Even of the abstract we come to demand technical proficiency. We corral our imagination.
In time we improve or abandon the pursuit according to circumstances and according to what we want. We buy a camera because we want to record a special occasion, a holiday or maybe our own children or children we are close to, a few of us because we are curious about pictures and want to get better at making them. Now- a-days, rather than buy a camera specifically we are much more likely to turn to our phones. The pictures we want to make are generally those we can create without the many hours and mess involved in painting, never mind the fine motor skills, which some turn into is photography art debates (Yes move on). Cameras and pictures are so much a part of society these days that picture making is pretty much second nature.
Most of those pictures being taken at this very moment are dull, boring, technically flawed and mean something only to the person who will forget they took it by tomorrow. They are constructed for different purposes. We decide to get better at this sort of thing and, suddenly, (nearly) everyone else’s pictures look better than ours. That can be a spur or it can put us off. Access to the ways of doing things is a lot easier now than it was, there are blogs and video channels aplenty as well as the more traditional routes through books and courses galore that blend all these. That, however, can make matters confusing rather than easier. So we know about the tools of odds, of thirds, of lead lines and negative space, symmetry, foreground interest and the effect of focal length, and the importance of balance and we know all about the exposure triangle. In fact we can know a lot about a lot and can still make pictures that lack impact.
The problem, at least in part, is that we have all these tools and rules but they are tools and rules of thumb. Certainly they exaggerate elements of the arrangement of the objects in the frame and hold others back but we keep coming up against the idea of technically proficient but subject deficient – and other people’s photographs still look better than ours. It is self doubt that becomes, once one has learned the basics, the biggest drag on learning. Sometimes we cannot see for looking. Sure, we need a mind open to development, open to seeing other people’s work, looking at other pictures in that picture but the frame of mind has to be positive and the habit has to be always looking for the picture – even when you can’t carry a camera. The habit is the thing that enables everything else, the letting go of the half-expectation of finding something to photograph and replacing it with the opportunities to see something to photograph.
That can be where club competitions come in. Yes we want to test our metal against others, but we also need feedback. No we don’t always agree with the judge, but we need to be able to say why. Yes the judging is subjective, yes its structure does mean certain types of photography may not fare as well, but it is a structured feedback on pictures that are anonimised and it is something that you can work with if you choose. The more experienced judges should come with a wider perspective anyway and whereas they will have their likes and dislikes – some of them strong – the perspective they are showing is a start.
If we can get into the habit of the feedforward loop we will do ourselves an enormous favour. Feedforward is when we take the experience of a previous occasion and use it to improve (control) a future event. Learning from the future ” Images of adaptive future behaviour, hitherto not mastered” (Wikipedia) or in our case getting the picture we see in our head as a Jpeg by design not accident, is something we can only do as design.
Next session is a 10 by 10 (or there abouts) where members talk about their own images, what they got from them, what they would do differently (among other things). Open to all members, bring some along and join in, especially our newer members, as we are all interested in photography and this is a good opportunity to share it.
Sid Jones, a member of the Dorchester Camera Club took us through a compact history of photography last meeting, which was well received by club members. Sid’s approach was to look at the key moments through technical advances in the chemical medium from Nicéphore Niépce and his associate Louis Daguerre, Fox Talbot and the gradual increase in the speed of exposure from 8 hours to, eventually, fractions of a second. He then explored some of the key figures behind the lens before giving us a selection of his most influential Twentieth Century Photographers: Ansel Adams, Eliot Erwit, Henri Cartier-Bresson to name but three. There are of course thousands of photographs that could make it onto anyone’s shortlist. So this weeks blog is a more leisurely look at the time line of the development of photographic processing from chemical to digital mainly with the help of the George Eastman House Foundation YouTube Channel.
Photography as we know it starts with the fixing of a photograph to give it a lifespan beyond the immediate. That was Niépce’s achievement, though light had been used to paint for centuries before that. So, although our hobby as we know it is barely 150 years old, it origins go back to ancient Greece and Aristotle (384 BC to 322 BC). Dageurre, though, was the person who produced the first useable, mass production method for producing photographs. Henry Fox-Talbot produced the first paper negative and then developed the negative positive process so many of us started out with, around the same time (calotype). Photography as a sharable medium over time was born in 1839. But it wouldn’t have got far without Sir John Herschel who not only invented hypo (“fix” for the image so that it didn’t immediately start to fade) but also came up with an iron salt based system with a predominantly blue tint known as a cyanotype. You probably know it in its engineering form, the blueprint.
The Albumen print came about in 1850 and is a version of Fox Talbot’s paper based process using egg whites, the invention of Louis Désiré Blanquart-Evrard, a Lille Cloth merchant it was probably the most popular form of print in the Nineteenth Century, not least because of the rise of the “Carte de Visit” which we looked at consequent to this seasons Chair’s Evening. Fredrick Scott Archer, butcher, silversmith, sculptor, inventor and photographer is next up with the invention of the Collodion in 1851, more precisely the Wet Plate Collodion. More viable than the Dageurreotype but it necessitated a portable dark room, the wet plate being the clue here, when the photographer was out and about. It was the process Roger Fenton recorded his Crimean War images on. As the Albumen print democratised photograph so the Platinum print, invented in 1873 by Willis and Clements and perfected over the next seven years, platinum printing, or the Platinotype, was an attempt to promote photography as a fine art. Platinum has never been a cheap way to do anything.
In the last quarter of the C19th, the so called pigment processes (Carbon Print Process, Gum Bichromate) where gelatine coatings to a paper base allowed for images to be reproduced in continuous tones with the excess being washed away to create highlights and the darker, hardened gelatine that remained formed the dark areas, came to wide use among the art school photographers still burdened by the doubts cast by their painterly cousins on the artistic value of a photograph. 1864 saw the invention of the Woodburytype, remarkable for the fact that it was a relief image that covered with pigmented gelatine could yield a mould that many thousands of copies could be run from. They look like photographs but they were actually made on a press, the gelatin covering hardening in relation to the amount of light it received.
The real mass market, the one that stands both sides of the camera, came fully into life with the Gelatin Silver Process. A late C19th century process, it was the first that didn’t really require you to carry your darkroom with you. It dominated C20th photography, it was the motor of George Eastman’s Kodak company, “You press the button and we do the rest” (1892). Colour, as we have seen elsewhere, had a long gestation. It all really changed around 2004 when the sales of digital cameras first exceeded the sales of film cameras. The digital age was truly upon us and Kodak didn’t move with the times quick enough. In 2012 they filed for bankruptcy.
It is all about the image in the end and the stories we attach to them – more of that next meeting. For the first time in Human history a true likeness could be taken of an individual, place or thing and, given the right process mass produced. Or put on the wall and treasured. Or left in the back of a draw to be discovered. We have had several conversations on the blog about notions of truth and photography and it is a continuing and evolving argument.
N E X T M E E T I N G
Critiquing your images – Ian Gearing.
Please note that there will not be a meeting at the club next week instead we are away at Backwell for a club camera battle. Said battle commences at 19:30 hours come along and support the club. Details are as per Gerry’s flyer here>>> Backwell Battle.
We were fortunate to have to the WCPF travelling exhibition again with us at the last club meeting, these prints were the ones that didn’t make it to the final cut. It was, as ever, as instructive as it was occasionally puzzling. We also had gold silver and bronze award prints to compare these to and there was much lively discussion about the relative merits. As has been said before, beyond the basic and accepted technicalities of the exposure triangle, focus, composition and subject and competition specific rules lies the more fraught ideas of what makes a good subject and a good image. What follows are some reflections from comments made and brief discussions had on the evening.
There were a couple of things that stood out quite strongly in the negative camp: one was to do with the style of mounting and the other was the overuse of the clarity slider in post production.
Let’s take the mounting issues first. Nothing says that the print has to be bang in the middle with an even border all the way around in order for a printer to be properly presented. Indeed variation can really bring a print to life. There were, and not just in this correspondent’s view, a number of prints that used letterboxing but set them in the top third of the frame in portrait giving undue prominence to the thickness of the bottom border. The effect of this was to immediately draw attention to the frame and distract from the picture because of the depth of the bottom part of the mount. Never in human history has the utterance “Nice frame” been a compliment. It was a shame that the frames swamp out some rather interesting images which were otherwise of very good, certainly club level, competition standard.
The Golden Ratio again rears its head and is supposed to produce the optimum border calculation (I will save you the maths, 6.05 cms on a 40 x 50 mount, for other sizes I direct your attention to the calculator at the bottom of the link). Nothing, though, says that a border has to be the same all round, it is a question of perspective. Think of the hinges on a door. When properly hung the top and bottom hinges are set at different depths from those extremities because we generally view these things from a standing position and if evenly spaced the perspective looks wrong. The bottom hinge is actually set higher so as to create an illusion of even spacing. otherwise it looks “wrong”. The frame of a print can be a powerful statement, but shouldn’t be so powerful as to overwhelm the statement the image itself is supposed to be making.
The clarity slider is a great way to boost mid-tones, or cut them back. It is an invaluable tool. Like everything else it can be overdone. There were a couple of black and white images that had the grit in the mid-tone turned up to eleven. Clarity works by increasing contrast but with a bigger effect on both the highlights and the shadows, essentially pulling out the histogram from the centre. Texture is more refined and certainly there is a case for a higher input when it is in need of a boost, and it does seem to work more effectively in black and white. Move the slider to the left then it has a softening effect (often the chief culprit in the charges of unrealistic portraiture or death by post-production). It’s not just clarity that can be overdone of course, saturation can become garish with very little input in the right (if that is the correct word) circumstances. Vibrance is the smarter sibling of saturation. It will select the dull colours and boost them whilst leaving the vibrant ones alone. It will leave skin tones untouched. Taken as a trio these are very powerful tools but need to be handled with care.
For all that these things are a matter of taste and therefore personal. Judging – and these were the entries that just fell short in the judges view – is as subject to fashion as anything else. HDR, partial colour remain controversial, not least because they are difficult to do subtly. That said, how dull would it be if every photograph was conducted purely to competition standard? I, for one, am glad of the variation.
A N N O U N C E M E N T S.
Next Meeting at Backwell Camera Club
Station Road BACKWELL
Bristol BS48 3QW. Starts 19:30 (7:30 pm).
Matthew Lord adjudicated round 3 of the 2014-2015, and the number of entries this year are well up on last in both print and digital categories. Quality is at the very least as good and I think this shows growing confidence within the club which itself is growing at a steady rate. If you haven’t put anything in yet, give it a go, you have nothing to lose and some feedback to gain to give you a start to think differently about your images. A club thanks to Matthew for his lively feedback and congratulations to those commended and placed.
Matthew talked about the way we look at a picture instinctively, though I would say culturally instinctively, because not all cultures have the same relation to space and the expectations of the artistic placement of objects within it, though most human’s seem to start top right when looking at an image. The brain discriminates (and tells you blatant lies, but that’s for another day), the camera cannot. The human eye/brain is not the same as the lens/sensor combination. Henri Poincare pointed out that the notion of space must be understood as a function of objects and all their relations, in photographic terms you can’t have an image without objects set in relation to each other. It’s often been reported here that our judges and speakers say that the photograph should have only one story to tell. The simpler the shot the more impact it is likely to have.
Yes there are composition rules, we have frequently referred to the thirds, fifths, sevenths and the “Golden ratio”, but composition (long video but very good and well worth putting time aside to watch), the punctum and the studium, isn’t restricted to this. Nor do they rule out simplicity. Simplicity comes with the fewest elements required to tell the story. Backgrounds can be problematic. They can give context, depth, even a certain tone. They can also provide too much information, confusing the subject with what it is set in, providing unfortunate growths like telegraph poles or trees. It isn’t always possible to pull the subject from the background, for example when using a long telephoto focused at infinity at a foreground subject which is far enough away to register the rest of the foreground sharp. Nonetheless, as a general guide and something Matthew picked up on more than once, your image rarely suffers from it and the tighter you crop the more impact your main subject will have.
Colour blocks can also make effective compositional statements. True individual tastes, perceptions and experiences affect the particular effect any given hue has on a person, but large blocks of solid colour in an image will almost certainly have an impact on the viewer. Blocks of complimentary colours can also have a powerful effect, think of the colour wheel and how colours interact. Again framing is an important factor in boosting impact.
Even if cropping the final image square, a personal favourite, the middle should be avoided, usually. This is because it is easy to unbalance a picture by making it static for the eye. The eye needs to move around the image for the brain to engage. By creating an off centre interest the eye will be drawn into space as a secondary motion. A fore middle and background is much stronger than a one or two element image. The eye looks for sign posts for direction and interest and will move long the former to stop at the latter before moving on. Lead lines are thus a very powerful element in composition. To work, however, they must all be a part of the story, or the eye will wander and the brain become confused as to what the story is (part of the reason is because the brain has an operational necessity for lower power consumption and so pre-programming certain reactions saves time energy and processing power, a little off topic but if you’re interested see Daniel Khaneman). Of course this can be played around with. Parallel lines can be a very bold statement, especially if shooting with a wide angle lens, even more so with a bit of Dutching
All in all a fascinating evening and again, thanks to our judge Matthew Lord and to Mark O for his efforts and everyone else involved. A gallery of winners will be posted when available which we are unable to post for technical reasons.
A N N O U N C E M E N T S
Next week – Medieval Combat! http://www.medievalmartialarts.co.uk Club members Ian Coombs, Danny Thomas, and Antony Bezer are bringing their mediaeval martial arts group to the club tonight for our latest practical session.
** Bring your camera & equipment ** **IMPORTANT** If you are attending this meeting you need to be aware that there will be rules set in place for your safety. ANYONE breaking those rules will be asked to leave the meeting immediately.
When: 19:30-22:00, Thu, 2nd April.
9th April: WCPF travelling critique. A show of the entrants to the WCPF salon.
16th April: Club Battle with Backwell. This year at Backwell. See here for further details from Gerry: Backwell Battle.
“Just do it and let others sort out their problems with it”, was Justin Quinnell‘s advice to the club on Thursday night. Apparently the pinhole camera, admittedly a minority interest, is rather divisive. To artists it is science. To scientists it is art. By this division, apparently irreconcilable, a fascinating and deceptively simple technique for creating long term expressions of the passage of time and not a little mystery is largely disregarded. Links nicely with David Southwell’s definition of photography quoted in last week’s blog ,”An art supported by science”, which seems to square that circle, and, while we are on the topic, a conclusion from the blog before that, that we use tools as a means of controlling what we can in order to look for the art in the rest. Problems of the world solved we move on with this fascinating perspective.
The effect is not new, that is to say, our knowledge of the effect is not new, though its use is contested. Aristotle (384-322 BC) knew of the pinhole effect. Justin has christened it “Aristotle’s Hole” and pointed out that it’s an effect in nature traceable over 5,000,000 years, possibly more. That isn’t an argument for Intelligent Design, at least not one I recognise, but it does show that as a species we seem to be constantly trying to catch up with the rest of nature. Justin had his audience hooked from the off and a gallop through the history of the pinhole, taking in pretty much everything from nature, a sieve and leaves (Aristotle’s implements of choice), mirrors, the camera obscura, ancient Greece, the Renaissance and modern times, certainly added to the evening. Did you know that there are pinhole glasses as well as pinhole cameras? You won’t be getting them on prescription any time soon though.
So, just what is a pinhole camera? Well it’s an enclosed, dark space with a single, small, hole in it positioned so that light can enter through the hole. Light, as we know from previous blogs and those lessons in school science that we paid attention too, travels in straight lines. When it meets a surface it turns an angle and continues in straight lines. If there is a light sensitive material for those straight lines to bounce back off then an image can be fixed. If that material is translucent then it can, as long as a modicum of shade is preserved be used as a screen to view the live image on. Pretty straight forward (though you can make things as difficult for yourself as you wish). Use a mirror and you can project onto another surface, such as paper where you can trace over the image (as long as the light holds). This is a technique that has a long history, though the question of whether that is an honourable history is a provocation itself and goes to the very heart of the question of what should be called art, which I think rather nicely brings us back to where we started this post.
Justin introduced us to some major practitioners, (of whom he is one), my favourite being where whole rooms have been turned into camera obscura’s and the results captured on video or stills photography. One day, maybe. The fact is the physical limits are well known and, as usual, the most limiting factor is the imagination of the photographer. Certainly his own projects have shown that thinking unconventionally doesn’t have to mean great expense. Maybe it’s simplicity works against it. At its’ most unadorned it requires the cooperation of others, a beer can or similar container, some gaffer tape, something with a point on to make a small hole, tin opener and a photographic medium. The idea’s of short and long exposures has to be adjusted. We are talking seconds/minutes not fractions of seconds for short exposures and months (if not years) for long ones. Interestingly – though I suppose quite obviously – there is no development involved. This is because it will go completely dark when you develop the image, or try to, if the fix hasn’t washed the image away. Instead digital comes to the rescue, either using a scanner or a camera – you could probably use your camera phone – and then the reverse option in an image editing application. The truly amazing thing is the latitude the paper negative yields, meaning that the image burning out is rarely, if ever, a problem. Justine was at a loss to explain why, but that does not prevent him from exploiting the phenomenon.
All in all a fascinating evening and one which, maybe, the club could follow up with some practical work?
N E X T M E E T I N G
12th March – Tonight we’ll be answering many of the questions you submitted about photography back in January. The topics will cover all the more commonly asked questions as well as a few unusual ones. Join in the discussion afterwards. Entries for 3rd round of the Reflex Open Competition now due. Final submission for Banwell Photobattle, co-ordinate with Alison.
19th March – an evening in honour of St Patrick, see this PDF prepared by our own Mr Gerry Painter RCC_notice_Ian
A N N O U N C E M E N T S
Firstly a very special Reflex congratulations to Ruth on her Ruby Wedding Anniversary celebrated last Saturday with family and friends at the Pomphrey Hill Pavillion, home of the Carsons & Mangotsfield Cricket Club. I admit I was ignorant of Ruth’s passion for the game until someone passed me this photo from her wedding day of Ruth appealing for an LBW.
Secondly, well there is no secondly, how could you possibly follow that?
Colour space and gamut. Sounds like a poor man’s crime fighting duo, but as Rich Price showed us it is a surprisingly powerful way to subtly (or not so) expand the presentation of colour in an image. Concentrating on derivatives of RGB, Red, Green, Blue, from which all other colours can be made and moving towards white, there are a number of different models – the basic physics of how we end up seeing the rendering – all existing to do the same job: Turn 1’s and 0’s into recognisable colours on screen or in print ( the model is the printer’s map, the image the contour lines). CMYK mixes cyan, magenta, yellow and black (the K stands for Key ), on the page and is popular with magazines and similar publications, and works by subtracting light from white as the start point. Then things start to get complicated with other models, such as CIELAB and CIE XYZ that approximate human vision in constructing colours and are used converting RGB images to CMYK. In itself all fascinating but not something that we need particularly concern ourselves with in depth. It gets very technical but is interesting.
So much for the models but we were concentrating on the work spaces. There are a number of them: sRGB – the most common found in display screens and cameras, PhotoRGB, the aforementioned CIELAB and Adobe RGB are a few. Rich concentrated on sRGB, and Adobe with a brief excursion through ProPhoto which Adobe use between LightroomTM and PhotoshopTM. Prophoto has a very large gamut, in fact 15% of it cannot be seen with the human eye. More is not always better, as with everything else, more is only useful when you have a need for it. If your image is looking muddy it is far, far more likely that you are viewing the narrower sRGB profile in an image that was modelled in the more defined Adobe RBG than the straight forward “fault” of the more limited spectrum. Most people cannot tell the difference most of the time. The gamut of any two profiles will have colours in common but when comparing sRGB and Adobe RBG the number of shades that can be represented between two points of saturation. What the smaller gamut will produce is an approximation of the colour defined in the larger one and necessarily, it will be different. The basis is in the degree of colour gradation that can be shown, that is the number of steps (shades) you can produce in the transition between two (complimentary) colours on the colour wheel. Just for the record the “small” sRGB colour space has 16,777,216 (256 for each of the RGB channels) colours in it.
The most likely time you will see the difference is when you print a digital image. Printer manufacturers have their own profiles and these are usually pretty easy to get hold of – unlike the Linux version of Adobe which seems to have disappeared from their website. These can then be loaded into your editor, the internet will show you how for your programme if you don’t know. Paper manufacturers also have different profiles for their papers and the respective manufacturers web sites are the best places to start with this. What this means is that if you are sending off your treasured image to be printed then you get a heads up on what the final thing will look like through your editing programme. It can change quite a bit, for example, an early morning mist shot I took yesterday, an almost golden light, when reviewed via a Fuji printer ICC profile downloaded from the print shop, showed some of the shadows moving from an almost dark chocolate to cyan – the valley opposite had oxidised! It also saves you time and money when printing at home, and quality inkjet ink is not cheap and cheap inkjet ink can quite often look it, especially on a quality photo paper.
Rich, when he started his presentation, stated that there is an important factor to be taken into consideration when we are talking about colour space, which can easily be overlooked and comes to us from the familiar colour wheel. Colour space is three dimensional, whereas the colour wheel as most of us remember it is two dimensional. The three dimensions are hue, saturation and lightness aka HSL aka HSV (v – value) and they form the backbone of all image editing software. What we are doing when we edit is navigating our way around this space, forwards, backwards, side to side and up and down and in a combination of these three. That gives us a clue that there are work flow questions to be answered here. Work flow in itself is a whole separate blog and we will return to that sometime in the future, but essentially it is all the production, administration and physical actions it takes to complete a process. There are many different forms of workflow, probably as many as there are photographers practising, but, when it comes to colour space there are some basics worth heeding – not least the effect your monitor is having on the images you are viewing and the accuracy and compatibility of colours when your image meets other devices. The club has a device for calibrating monitors which is available to borrow to club members. Ask about it at a meeting if you want to know more.
The second half of the meeting was a practical and members were busily engaged in the delights of LightroomTM and PhotoshopTM and there were more than a few “Aha!” moments. So, our thanks to Rich for his time and energy in putting this together. Next meeting is our own Adrian Cooke who will be talking us through a selection of his images.
Next meeting is also the deadline for Deadline for “Dear Reflex…” questions “Dear Reflex…” is a question and answer session where club members can ask any photography-related questions of the club. These will later be presented to members who will have the opportunity to volunteer to answer them, and given time to present their answer.
See you Thursday!