Quiz Nights. You can’t beat them so we joined ‘em. Thanks to Myk Garton for putting the evening together, I know from first hand experience just how much effort goes into making it look effortless. And of course all participants showed themselves masters of their hobby. This week on the blog we will wrap up two of the three remaining questions from the Week 2 Q by looking at: What is front curtain, rear curtain and slow flash? And what is Back button focus? This week has also been the big European photographic trade show, Photokina, held in Germany, one year I will have sufficient time and money to go …..
Still, daydreaming aside, what is front curtain, rear curtain and slow synch flash? Flash, aka strobes, aka those lighty things, is an area that is both technical and often ignored by the amateur. Yet it is one of the most effective accessories we can purchase. After all most of us have one built into our cameras, even if it does get overlooked most of the time. There is more to this than we will look at here, indeed we will visit this in a future blog, but for now we will explore the question that was put concerning these three often found menu options.
For this specific question we do not have to differentiate between off camera flash (or strobes if you prefer) and on camera (that is pop-up or otherwise built in). The reason behind this is that this is a specific question of the firing order of the flash in relation to the curtain or shutter. Mostly this is done off the position of what is known as the front curtain. The majority of cameras have a two curtain (shutter) set up. This enables faster shutter speeds, the flash synch speed of your camera is actually around about the fastest speed that the whole of the sensor is exposed. Otherwise it is exposed through a slit formed by the front and the rear shutter curtains moving across the sensor plane at a fixed distance apart. The faster the shutter speed the closer the gap.
If you expose using a strobe/flash unit above the flash synchronisation speed you get a dark band of varying width according to the shutter speed as the duration of a flash is extremely short. Because the lens projects things upside down onto the sensor and the shutters move from top to bottom this band will appear from the bottom upwards. Not so much of a problem if you only need light at the top of the frame, but not actually something that is easy to fine control both because of the position of the shutter at any given time and how much darker the rest of the frame is.
So why have a front curtain flash and a rear curtain flash? It’s to do with the motion blur in the frame and where the pulse of light freezes that in time. The least subtle explanation, nonetheless one that actually holds true, is that you use front shutter curtain to freeze the action. You might use your maximum shutter synch speed (often automatically set but that depends upon make and model of your camera body) to give yourself the maximum chance of freezing the action. You use the rear shutter curtain and, usually, a lower shutter speed to freeze the foreground and retain some motion blur in the scene. And slow synch flash? Well that is an automatic camera mode that forces a slower shutter speed and synchronises the flash. You can get some very different looking results from the same scene using these variations. As ever, try it out for yourself.
Back button focusing, once you’ve tried it you will never go back. At least that is what its fans say and there is no denying that it is a very useful tool. We looked at this on the blog last August viz “Back Button Focusing (refer to your manual for the native translation in your Camera’s Brand-Speak) does exactly what it says on the incredibly expensive magnesium alloy tin, or plastic camera body as befits your pockets/needs/delusions of grandeur. It is a button on the back of your camera body that activates the camera’s focusing system in isolation from the shutter release. When you operate via the shutter release a half pressure triggers the autofocusing system (assuming you are not mounting a manual lens) and a full depress activates the shutter release. Usually the shutter will not fire until the camera processor detects all the algorithms are in place to produce a point of focus and an acceptable circle of confusion (i.e. something is in focus …). The button itself is usually marked AF or a version thereof and is normally accessible with the right thumb (I’ve never seen one on the left but then I haven’t conducted a survey in any depth). And it’s on the back of the camera.”
Yeah, that is what it is but what use is it? Well first off there is the fact that, whilst depressed, the AF button means that you hold whatever it is you have focused on. In the automatic modes focus shifts when you shift what you are looking at, which can be time consuming. In order to keep the focusing, for instance if you want to shift the main point of focus to the edge of the frame and blur the background. You might want to add to that you can use the continuous mode (AF-C or AF-Servo depending on your camera body manufacturer) of focusing on your camera when following action and use the AF button to freeze the most advantageous point (takes some practice but worth the effort with a high degree of movement in the frame). Or basically no more having to focus every time you let go of the shutter which takes time and can mean that you loose your shot. Annoying when it was already in focus the last time you half depressed the shutter.
So now you know. Next meeting is Table Top photography, a practical so bring your cameras and tripods. Maybe your flashes too!
Last meeting was convened at the Grand Pier Weston Super Mare for a evening’s photography along the front covering both Weston Bike Night, the beach and the sunset across the Bristol Channel. Have to say that the clouds and the sun didn’t disappoint and the turn out wasn’t at all bad given the weather forecast and people’s work commitments. Certainly the black of the rain bearing clouds in banks and the gold of the setting sun made for interesting vistas out over the Channel to Flat Holm and Steep Holm. Of course there was also the Grand Pier itself, which is not exactly a hidden feature, Brean Down and Knightstone Island.
So this week a little on photographing motorcycles. It goes for cars too but your Blog editor is a motorcyclist, so that’s what we are mainly going with. There are not quite a half dozen of us in the club I know as motorcyclists (there are a few more former motorcyclists) and a couple of us have trekked with our cameras over the years to the National Exhibition Centre for Motorcycle Live and other venues and events. As machinery goes motorcycles are actually quite photogenic, but they are not, necessarily that easy to photograph well. In the street they are either moving among traffic – not the easiest of things to get a clear shot of – or parked on a side stand – occasionally a centre stand. Usually among other motorcycles, which doesn’t always work out favourably for photographers. In more rural settings they are generally a blur of noise and speed, or parked up as per the above.
Certainly shows and sporting events are the best way of getting chances to shoot more memorable images. Also going to and from events like the Weston Bike Nights (Thursday’s over the summer), Poole (Tuesday’s and, possibly, the biggest in the UK) and Paignton (Wednesdays) at a suitable and safe place can be good too. Static displays can be captured at wide angles but the pictures with movement in generally speak to short telephotos. This speaks to both practicality and safety for you and the riders, who, by and large, tend to be quite friendly.
The most important element, as ever, is the photographer, not the equipment, but as we are talking equipment then the statement about lenses made in the paragraph above needs to be qualified. The “best” focal length is probably short telephoto, certainly 50mm and above. The reason for this is that the shorter, wider lenses, add an element of distortion which can exaggerate the length of frames or make wheels look, well, not very round. This is fine if that is the look you are after, but accurate record (side on) shots, regardless of how creative, really need a perspective that 50mm and above create.
Apertures, more often than not, tend to favour the wide. This is because the background easily distracts and it is not unheard of for there to be gaps in the bike frames, especially on classic bikes, where in focus backgrounds can be a little diversionary. In fact one of the best pieces of advice I have been given about taking a photograph I have heard – though it can be a counsel of perfection as with any other – is start with the background first. Keep confusing strong lines and confusing strong colours that clash with the paint scheme of what you are trying to photograph out of the frame as much as possible. Of course, if you are photographing a row of motorcycles then the depth of field might well need to be deeper, but generally a moderate depth of field will allow for some background blur and sufficient depth to allow for the bits that stick out of the frame to be kept reasonably sharp. Remember here we are still talking about taking images of static bikes.
As with most forms of photography a low angle to the sun helps with illuminating the subject, so getting up early in the morning might not be avoidable, though Bike Nights cure this affliction. However, shooting from a low angle is pretty much standard. One other piece of equipment that can prove invaluable is a reflector. You can get a 5 in 1 cheaply enough from eBay (I have seen 60cms reflectors for £5 and 110cms for a shade under £10), and it is a good investment because more often than not there will be areas around the engine that are in shadow and rather than faff around in post light reflected back onto the engine and frame can eliminate the problem at source. Also very useful for other sorts of photography too.
On the move there are a different set of circumstances to be taken into account. Primarily safety. It’s very easy to get lost in that narrow field of view that is the world through a viewfinder but we have to be, legally and morally, aware outside of it. If you want movement shots at the Bike Night or other event get to know the approach roads on a map before you go. Roundabouts tend to be a favourite, the larger ones at times without too much traffic flow are generally good for getting pictures of bikes at an angle of lean. Actually any bend is good that requires more than minimal input from the rider. Lenses will depend on the situation that you are taking the pictures in, but again telephoto makes more sense, especially from the point of view of safety. Of course you won’t be the only one who has thought of that, and some people make money out of doing so – some organised events have cameras at the entrance so you can see yourself arriving – for a price. Whatever the case you are going to have to sort that out according to the location and some common sense.
If you are at a motorsport event then there are a couple of givens. The pro’s have all the best spots. You will be a longish way back from the actual action. That said there are a couple of obvious things you can do about that. Position yourself on a or as close to a bend as you can. Easier photographing a bike doing one mile a minute rather than three miles a minute. Your autofocus will thank you. Actually it will thank you for turning it off and zone focusing (pre-focusing), but more critical is slowing the action down relative to the camera position (usually head on or as close to it as is possible safe and desirable). Motordrive is an option that shouldn’t be over looked but it has to used deliberately. Spray and pray won’t get you a huge amount of useable material. Chimping is a great way to miss the action totally. Panning is an art that requires a lot of practice but if the shutter speed is low enough and the focus on the moving object good it gives a great feeling of speed (which actually can be very low, as per most supercar on road magazine shots). Go out and give it a go its actually rather fun.
N E X T W E E K
Tintern: – which means bridge tolls so lifts etc might be a good idea.
Meet in the Abbey Car Park at 7:30 pm.
Change of venue to a walk around the docks in pleasant company, always interesting thing to photograph going on as it is now a social centre for the city. It being evening and ending after dark rather suggested that we take a look at night photography, both with and without a tripod.
On the face of it, night photography is defined by two of the absolute essentials of photography. Firstly contrast, you have to go and find it. It will either be very low, which can make things muddy and ill defined or very high, which can call into question shadow and or highlight detail, losing it mainly. Then there is the whole light thing, rather the relative lack of it and the effect that has on the exposure triangle, camera shake and sensor noise.
Situation is also key. This post is going to look at the urban setting as that is where we were, which sets a very different array of questions than say, photographing the milky way in the Brecon Beacons. Urban settings have more immediate and multiple hazards, multiple opportunities too. That is not to say that you should go prancing around the countryside with anything but due care, it is a far more dangerous place than townies think.
Whereas there is a joy in wondering around looking for photo-opportunities you are far more likely to find them if you know what you are looking for (planned serendipity). Let’s start with the golden hour. The Golden Hour isn’t exactly an hour, it is short hand for, in photographic terms, a quality of light that is a function of the relationship between the angle of the sun to the earth. During that time the colour temperature of the light is around 3500 Kelvin because of the greater depth of the atmosphere it has to travel through.
Now you say, being on the ball, that makes the light bluer than the standard daylight of around 5500 Kelvin and you would be right. That soft quality of light that makes for good portraits as well as land, urban and seascapes (we will ignore sun rise for the purposes of this piece but the golden hour is that which starts around dawn) is a product of the low angle of the sun to the horizon which scatters the blue wavelengths relative to the red/yellow wavelengths which, psychologically, look warmer to us. Think instant no cost tanning. That low angle means long shadows too that are also softer than you will experience later in the day.
The time it is available is limited so there is a time pressure (though no excuse for bad technique, of course). It’s all in the preparation (a point worth repeating). Cloud cover will need to be monitored and factored in too. Knowing when today’s golden hours are, or tomorrows etc, depends upon your planning window, is fairly easy to calculate. I feel almost obliged to mention The Photographers Ephemeris at this point. It also worth persisting throughout the hour because of the speed the light changes is so rapid. ISO’s are likely to be higher and/or apertures wider and the White Balance, which will try to correct to daylight if left on auto, should be set to cloudy to preserve the warmth in the light.
Not that the setting of the sun should stop you, the urban landscape presents a myriad of possibilities, some of these we have spent some time on club outings photographing. The first thing to remember is a piece of advice from Scott Kelby and that is the last thing you do is put the camera on the tripod. Make up your mind what you are photographing, “Working the scene” to determine the most productive angles. Then fix the static element around that rather than restricting yourself the other way round. Handheld is also an option, depending on vibration reduction/how steady your hand/availability of something solid to brace yourself against or set the camera. Another tip I have found very useful is, when holding everything steady as you can, is to shoot a sequence using the motor drive that is built into virtually every camera these days. Five will get you one steady shot more often than not, though there are, of course, limits to what you can achieve. Wide angle are a lot easier to get results with this way than telephoto lenses which, with exceptions, need a tripod.
The lights in the urban environment are both static and mobile. The very wide and the very narrow are both good for picking image subjects. Cityscape panoramas provide, usually, both static and mobile elements. Shop windows, street lights vehicle light trails. Getting high up, windows, multi storey car parks with a view, bridges and alike offer vantage points. Shop windows make for a great free soft box for street portraits. Neon light always sticks out and often uses reds and yellows which are particularly striking and blues can be arresting set on a dark background. Reflections in windows or water are worth paying attention too. The light sources in the scene really are the first thing you should weigh up These are, light trails aside, entirely static. Waiting for something or someone to come along and add interest to it is really quite logical.
Exposure is always going to be tricky at night as we discussed above, because of the high dynamic range that you will be dealing with. This is one situation where it really does make more sense to shoot in RAW than in JPEG (or, if you want your cake and eat it, both) unless your camera is using a version of HDR with a high ISO and a black frame to reduce the noise, which will be a built in function and therefore not one where you have the data format option, necessarily. Noise reduction in camera will slow down the write to card times by approximately the same length of time as the exposure so if you are going longer than a second or so and/or shooting sequences with long exposures it probably makes sense to turn it off and do your noise reduction in post.
Flash has it’s uses, but not if you are trying to be discrete. Nonetheless, meter for the highlights, shoot camera RAW, accept that post production is almost inevitable in these things. Dark images are not necessarily a bad thing, you are shooting at night after all, but the mood after dark is always different. The mood of some people is also rather different so make sure you play it safe. The tripod is a good idea, of course, especially if you are looking at longer exposures, when it becomes an essential, either because of the generally low light levels or because you want to include some blur in your subjects – also useful if you are putting in some zoom blur too – or you are looking to put some light trails in, as discussed above. And we haven’t even broached the subject of light painting.
All in all a great way to extend your photographic day and pretty much what e shall be doing at WSM this Thursday, with the added incentive of it being bike night. See you there.
Off to Weston we went, aka “Super-Mud”, last meeting and though the skies were lowering the turnout was pretty good and a good time was had by everyone I talked to. What more can you ask for? Well it was Weston Bike Night, organised by the Royal British Legion Riders Branch, and runs every Thursday from May to September. So I hopped on my motorbike and made my quid (£1) donation to the RBL to park on the Marine Parade Lawn and wandered round with my camera, before meeting up with the rest of the club on the beach by the Grand Pier. They had, it turned out, been taking pictures of a convict making his way up the beach, with the express purpose of compositing them into a single photo in post production (Photoshop, Gimp). If you look back through this year’s competition galleries you will get the idea of who and what sort of thing. The sun also made a show right at the end of the day and we were presented with a salmon pink sunset against the grey of the clouds as a finale. Not too shabby.
It is often said, not least by me, that in photography, painting with light, the light is everything. So far so obvious. What we are really saying is that the contrast in any given light situation is everything, as the same subject in different lighting gets a different reaction from its viewer. We are not just talking of low light here, where we have options within the exposure triangle, and in the way the camera works in other ways, but, when the weather is as it was on Weston’s beach and the contrast is low, the temptation is to save it for another day, but we can be missing opportunities. Contrast is what determines how “flat” the light in your image looks. Possibly, most logically, we can see this in monochrome images, but it most definitely applies to colour ones too.
Essentially, contrast comes in two flavours. Thinking of the black and white image and we can imagine the more obvious of these expressed as a tonal range, which we have touched on before. The tonal range is that between (theoretical) absolute black to (theoretical) absolute white which we would affect in post production editing programmes through levels and curves. The second flavour is colour contrast which is about the predominance of a colour in relation to the colours around it.
When we are producing black and white photographs we are really talking producing images constructed of the shades of grey (no tittering at the back). Soft images record little range in those shades, it is all middle and very little of the absolute ends, whereas hard looks stark because we have a band of hard blacks and a band of hard whites and very little in the middle. This is not the same as low key (mostly darker shades of grey surrounded by blacks) and high key images (mostly lighter shades of grey surrounded by whites). The emotional tone that low key images give out tends towards the sombre whereas high keys have a lighter mood, but tonal contrast isn’t just limited to black and white.
Colour, as we have explored before, tends to overwhelm tone when provoking emotion in a viewer, but good tone is a major element in the construction of a colour image too. Because there is more variation in colour, more information to play with, then the possible outcomes are multiplied accordingly. Broadly the more saturated a colour is in relation to the others in the image and relative to its position on the colour wheel. The degree of saturation is also important to colour contrast and that can be affected by exposure (try bracketing a couple of shots by two thirds of a shot and look at them in comparison, warmth, feel/mood can be subtly or not so subtly effected.
Meanwhile, back on the beach at Super-Mud, we are faced with some impressive cloudscapes that are throttling the contrast out of our seascapes, aided and abetted by a distant haze shrouding the South Wales coast. Looking on the (not too) bright side we are not trying to photograph either a black cat in a coal hole or a polar bear in the Arctic). Those both represent zero contrast situations. Give up go home, assuming you survive contact with said cat and/or polar bear. As we are in neither we can do something about our rather dull scene (other than retreat to the pub). All the rules of composition still apply but we are not bereft of options. The exposure triangle was mentioned above and in pushing two of the elements in that, aperture and shutter speed, we could just make a keeper.
Exposure Value Compensation it’s called and it’s that button that allows you to adjust the average that your meter is measuring up or down, usually by up to two or three stops, depending upon what camera you are using. It does not matter whether you are in Shutter or Aperture Priority or shooting in manual (though this is a bit of overkill bearing in mind you already have control of aperture, shutter and ISO in manual mode, but it is possible to employ as another way of under or over exposing from the average). First meter as normal then apply +0.3 ev on the scale. Try again up to a stop, or in the extreme, up to 2 stops or more, basically adding dark. In manual you will possibly be moving in half stop intervals depending on the age of the lens, but most modern ones seem to move in thirds. The same basics apply. Shoot in RAW for the best post production options. What you will do here is affect the colour contrast. Yes the whole image will look progressively darker, but that is not necessarily a bad thing. On the Mini group trip to Weston, where there was a vivid orange sunset, this actually strengthened the composition by allowing the sky and certain reflections to be the focal points against an increasing rich, dark background. Essentially for this technique you are looking to set the narrowest practicable aperture matched with the highest shutter speed you can get a workable image in the light conditions.
Try it next week when we visit Portishead Marina. Dock Gates, 7 pm. See you there.
A big club thanks to Medieval Martial Arts for their visit last session, it certainly was a meeting out of the ordinary! From the postings to the club Facebook Page I see that the opportunities were well taken up. Look forward to seeing some of those on their website. Set me to thinking about action shots.
Action shots are not just sports shots. Yes sports shots are about freezing the action, but even so panning to keep the subject in focus whilst blurring the background is an important variation of the fast-lens-fast-shutter-speed-freeze-action photography that might spring to mind. But, as ever, it is NOT about the KIT, it is about the PHOTOGRAPHER. Well mostly. The equipment can help and when you are being regularly paid to get the shot, not moan about not getting the shot, then the margins, which may be small, are worth the considerable investment. Otherwise it is the case of all the gear and no idea. Not a problem if you can afford it in both the financial and the emotional senses. Big problem otherwise.
Scott Kelby reckons that there are, essentially, four identifiable elements to action photography (sports, specifically but the terms are interchangeable for our purposes): Isolation; Getting in close; Good technique for all likely environmental situations met; Equipment (see above). It is important to note that the last does not stop you taking action (specifically sports) photographs, that technique can help, but there are physical limits and those met on a regular basis might be the reason to buy – if used regularly – or hire – if not. The two things they all do is action and emotion. Hard to get the emotion when dressed head to toe in protective gear including visor, but hey, you have to look for it in the raise of an arm, the tilt of the head, in other words in the body language. The one thing that helps more than anything is knowing what is going to happen next. My contribution to the Medieval night was, admittedly of very little artistic merit, to try and show some of the flow of the action, so shot with animated Gifs in mind so as to show form, predominantly. It was a spur of the moment thing as I can’t use the clubs flash triggers with my Sony. The results show thinking is required and it is because I don’t know the activity I ended up using an ultra wide lens and high ISO and the motor drive in an effort to follow the action. The ones that worked best were the ones where I had an idea of which way the action was going, that is the ones that didn’t show the characteristics of a drive-by point and hold the trigger till the buffer gives out. A certain amount of anticipation was required as at 10 fps the buffer soon fills (tip, change from RAW to medium JPEG, you get a lot more bang for your buck).
More often than not the results were so so, but the few sequences that worked better were towards the end of the session when I had a better idea. I also tried a 50 fps video which worked better than I thought but action photographed at 1/100th of a second isn’t going to produce great stills, before you consider that 1080p produces only 2.1 mega-pixel images (fine for a web pages maybe?) NB: You can use faster shutter speeds, each frame is a separate image but the shutter speed is usually calculated at (a minimum of) twice the frame rate – as a rough guide. The 2 x frame rate shutter speed gives the sort of motion blur our eyes are used to. Go too far and the action looks jerky, rather like an animated gif, which is where I started. The exposure triangle still applies.
Not all, however, action shots are strictly sports, of course. Nature photography also is a major contributor to capturing movement. Birds in flight are a pretty good test of the four elements Kelby outlines for sport. One technique that stands out for both is rear or back button focus, where a button on the rear of the camera does the focusing for you and leaves the shutter release purely operating the shutter. This is a function to be found on most DSLR’s and DSLT’s. (This shouldn’t be confused with back and or front focusing between lens and film/sensor plain which is where the sharp focus in your images is consistently just in front or just behind what you want to focus on and is a technical problem). The reasons for the commonalities between sports, nature, air shows, dance and the rest, though the subtleties are different and multitudinous, is the fact of movement, or as we have called it, action. That is to say the techniques are worth learning even if we only apply them occasionally, in which case we need to adapt to the equipment we have as it is generally cheaper than a divorce settlement, as Kelby points out.
None of this negates the idea of the decisive moment, and certainly there is more in the elements Kelby talks about when they come together. Mark this, however, about the equipment. Cartier-Bresson didn’t have access to a motor drive, photography, for him was an “Instrument of intuition and spontaneity”. Each frame on his Leica was a double throw of the film advance lever, by which time history had moved on. Not, given his training and philosophy, that point and squirt was likely to have formed part of his working methods. As he observed, “There are no new ideas in the world, only a rearrangement of things” and he didn’t shoot movies. Nor, the odd cyclist apart, did he shoot sports, or martial arts, come to that, and if he did he kept quiet about it so it probably didn’t turn out too well!
You can contact Medieval Martial Arts through their website, for this sort of thing or, if you pefer, in slo-mo and again thanks from us for the opportunity to think about and practice our hobby on something different.
A N N O U N C E M E N T S
Thursday 9th April 2015: The WCPF Travelling Critique. Entries to the WCPF competition which gives us an insight into the standard out there and also opportunities to do our own critique. For some guides to criticism click this link Reflex WCPF 2014 Blog or enter the terms in Google, it is the top two results, or keep scrolling down on the blog page till you come to the posts marked 10th and 24th of April 2014. WCPF for more details from Gerry.
Thursday 16th April 2015: Club Camera Battle at Backwell. F8 and be there. Backwell Battle Gerry tells you all about it.