Photography Tips

IMGP9160

Red-eyed subject

It is good to have the eyes of the subject sharp and looking at you – but it is terrible to have them red, and if you take your pictures using your camera's built in flash, there is a good chance that the eyes will come out that way. The red is the light reflected from the back of the subject's eye ball, and when you use your camera flash the light travels straight from the flash to the eye ball and back to the lens, to be captured by the sensor.

Part of the problem is that we mostly use flash when the environment is dark, and when the environment is dark the pupil of the eye opens wide to get more light, and the wide-open pupil makes it easier for the flash light to get in and the reflected light to get out. Now, there are a couple of ways of making the pupil smaller, reducing the risk. One is to shine a bright light at it just before taking the picture, and this is what the pre-flash, or red eye reduction feature, does – it makes a quick flash just before the main flash, giving the pupil time to contract. The problem with this is that it can also cause a change in the subject's expression, and if you do a lot of it, or flashing generally, can lead to a change in the subject's temper. 

Now , if the room were brighter, the pupils would not be so dilated, so if you turn up the lights in the room there is a better chance of not cpaturing red eye. Of course, if you turn up the lights in the room, you might not need to use flash at all, particularly with the greater range of noise-free ISO levels in modern SLRs. Even without turning up the lights you may still get a reasonable, if slightly noisy, picture, by using higher ISO and no flash.

If you must use flash, use an external one rather than the built-in one on the camera. If you set the external flash on the camera hot shoe, the change in angle is such that the bounced red light will often miss the lens and so is not captured, and you can avoid any chance of it by aiming the flash away from the subject, something not possible with the built-in flash. If indirect flash doesn't give enough light, you can use a diffuser. Some people advocate keeping the flash off the hot shoe, connecting it by cable or wirelessly to the camera, but now you need to use one of your hands to hold the flash and that leaves only one to hold the camera, which is not enough. You could use some sort of bracket, but that makes things very bulky.

There will always be people who tell you not to worry about red eye, as you can fix it afterwards in your favourite photo editor. The problem with this is that the editor doesn't know what colour your subject's eyes were, and while it can satisfactorily change them from red, it has to change them to something, and often that something won't be right.

You might have noticed that there are two tips this week. This is because we have missed a few since the start of the year, and should by now be on Tip 26, so over the next couple of weeks I'll try to get back on schedule.

I visited Karl McDonagh's exhibition of old photos during Carlow Arts Festival recently, and was struck by the eyes.

Eyes

Eyes

In every one of the hundreds of pictures the eyes were sharp and looking straight at the camera. Now, those photos were photo-journalism, and mostly posed, and looking at them you can almost hear the photographer asking the people to look at the camera, and so you would expect eyes to be sharp and looking. But this is the point. Instinctively, if there are eyes in an image, whether human or animal, that is the first place we focus on, so that we can tell if they are going to attack us, or we should be attacking them, or whether we or they should be suitably submissive to avoid getting trounced. Because of our instinctive focus on the eyes, we should ensure that they are sharp, and for greater effect have them on one of the thirds of the image.

If your picture has eyes, they should be sharp.

Cap Backwards

Cap Backwards

Cap forwards

Cap forwards

Do you wear your cap peak to the front or peak to the back? If you are wearing it for decoration, it doesn't really matter, but if you are wearing it to shade your eyes from the sun, peak to the back doesn't work. Now, the nice lens manufacturers thoughtfully provided the equivalent of a peaked cap for your lens – they call it a lens hood. And just like the peaked cap, it can be fitted sticking out to the front or tucked neatly over the lens body facing backwards. And just like the peaked cap, unless you are using it just for decoration, fitting it backwards doesn't work.

So, why does your lens need shading? It needs shading because without it, as well as the light from the subject area, which goes straight through the lens elements to the sensor, light from outside the subject area will also hit the lens, at an angle, and some of it will be refracted though the lens elements and cause flare in the image. The flare may show up as faded, over-exposed patches, or it may show up as bright multi-sided spots, which are actually an image of the diagphram that controls the aperture. While sometimes – not often – the aperture spots can enhance an image, most times flare is undesirable, so you need your lens hood forwards to minimize it. Even when taking night shots or working indoors it is better to have it mounted the right way. About the only time you should remove it is when using camera-mounted flash, as then it can block some of the flash light and cause shadows.

The lens hood in the forward position has a couple of added advantages. If it starts to rain, and we know it does in Ireland from timme to time, it will reduce the chances of raindrops on the front lens element. The raindrops might not harm the glass, but they can ruin a shot. And if you are inclined to bump your camera into things, better to break a relatively cheap bit of plastic than an expensive piece of glass.

Beware when taking pictures with the camera's built-in flash while wearing a peaked cap. When you bring the camera to the eye the peak can depress the flash unit enough to deactivate it, the flash won't fire, and you'll be stuck wondering why it didn't. For that circumstance, it's cap peak backwards.

Nothing to do with the tip.

Nothing to do with the tip.

It is also called, depending on your camera manufacturer, Image Stabilisation or Vibration Reduction. Irrespective of the name, the idea is the same – if you are hand-holding the camera, there will be some movement of the camera while the shutter is open, giving some amount of blur to the resulting image. SR/IS/VR attempts to compensate for this movement to give a sharper image. We do not need to consider how it does this, except to mention that in some cases the technology is built into the lens and in others it is in the camera body.

Now, if there is plenty of light, the shutter is only open for a very short time, insufficient to have any significant shake captured. Also, the shorter the lens focal length, the less any shake will be magnified, so we are really concerned with lower light and longer lens situations where the camera is being hand-held. At this stage it is worth recalling the “rule” for hand-holding – take the focal length of the lens as a fraction of a second as the limit of exposure time. For a 50mm lens, don’t hand hold for more than 1/50th of a second. For a 300mm lens, the limit would be 1/300th of a second. For those of us with APS-C size sensors the limit is increased by a half, so the 1/50th becomes 1/75th, and the 1/300th becomes 1/450th. While most times there is enough light to allow something faster than 1/75th, even quite bright days with a mid-range aperture will struggle to allow faster than 1/450th.

So, it is a dull day, you are using a 300mm lens, APS-C sensor, you want f11 to get a reasonable depth of field, and the suggested shutter speed is 1/100th. The rule says don’t hand hold. You could, indeed you should, put the camera on a tripod, but maybe, despite being an avid reader of our tips you have forgotten to bring it. You could put the camera on a convenient wall, if there is a convenient wall, and use the built-in timer, and hope that in 12 seconds the subject won’t have moved. Or you could turn on your shake reduction, which will give you about 3 stops. From 1/450th, one stop gives 1/225th, another gives 1/112th, and the third gives about 1/60th. We only need 1/100th, so SR/IS/VR saves the day!

One of the nice things about SR/IS/VR is that, most times, it does not do any harm, so rather than worrying about it, you can just leave it on all the time. However, there are a couple of situations where it should not be used. One is when the camera is on a tripod, so unless you have a recent Canon camera, turn it off when using a tripod. (Recent Canons automatically shut it off when on a tripod). The other principal case is in really low light situations, such as night shooting, but then you’ll be using a tripod anyway.

The tip, then: when you take the camera off the tripod, turn SR/IS/VR back on. When you put the camera on the tripod, turn it off. And if you use a Canon, turn it on and forget about it.

not seen in Oak Park

not seen in Oak Park

Sunday last was National Dawn Chorus day, when bird-watchers get up well before the crack of dawn to gather at various pre-determined places to listen to the wonder that is the birds’ dawn song, at its peak in the middle of May. The Carlow gathering that I attended was at Oak Park.

Since it is not a good idea to go rooting for clothes at 4 in the morning, risking the wrath of the other household member, I selected and set out my gear before going to bed. While doing so it struck me that such preparation is similar to that needed for an early-morning photo-shoot, and that it is not easy to take good photographs if you are cold or wet. It is important to dress appropriately.

One consideration is that, no matter how mild the weather, you need to dress more warmly for an extended period with little or no movement than you do when going for a brisk walk. Extremities will get cold, so wear a hat that will pull down over the ears, thick socks and boots, and gloves – if you can get them, the ones with fold-back fingertips. Several layers are better than one heavy layer, and things with zips on the front are great for quick adjustments of temperature. As the day warms up you can consign one or two layers to the backpack.

Another consideration is, as mentioned in a previous tip, we get rain in this part of the country on around 150 days a year, so there is a good chance that it will rain, or has recently done so. Your boots of course should be waterproof, and warm waterproof trousers are also advisable, and if your top layer is not waterproof, a light waterproof windcheater should be in your backpack ready for use.

If, of course, your photoshoot destination is not dawn in the country, but midsummer midday in the city, the notion of what is appropriate will be a bit different. The sturdy boots with heavy socks can be replaced by comfortable shoes and ordinary socks, and the trousers need not be waterproof, nor the top, as if it rains you pop in to a café until it stops. Likewise the number of layers can be reduced.

Whatever the destination, consider the weather forecast, and the importance of remaining warm and dry with relatively little exercise. Comfortable photographers take better photographs.

Always take a banana on a journey

Always take a banana on a journey

The topic of this week’s tip is the humble plastic bag. Just as you should never set out on a journey without a banana, so you should never set out on a photo shoot without a plastic bag. This is Ireland, where it rains on at least 150 days every year, and even more in the West of the country, which means that there is an excellent chance that, when you go out with the camera, it will rain. So when it rains, and you are just getting the camera nicely set up on the tripod, you take out the plastic bag and cover the camera, and if it is windy put on a couple of elastic bands (you did bring them, didn’t you?) to hold it in place. Even if your camera is nominally weatherproof, covering it will help, and at least will make it less unpleasant to handle when the shower passes.

Now of course you might get lucky and be out on the day it doesn’t rain. But if it isn’t raining today it almost certainly was yesterday, and the grass is still damp, so when you go down on one knee to get that better angle, how do you stop your trousers getting wet? Why, by kneeling on the plastic bag, of course.

You’ve taken the shots. You’ve reviewed them and discarded the failures. You’ve done the post-processing. You’ve backed up your disk. What happens next?

You are taking thousands of shots a year, maybe 10,000 or more, and some of them are good. Some even are very good, and you pick out a dozen for CPS competitions, and another one for the Exposure exhibition. Who gets to see the rest? You might put a few up in the CPS gallery, or even on facebook, but it is a sad fact that most of them will lie on your hard disk until eventually the bits fall off. So print some, and show them to people. Pick out the best dozen or so from a shoot, or from a holiday, and make them into a little booklet, maybe postcard size prints or a bit bigger, and pass them around friends and acquaintances. Of course, do it too often and you soon won’t have very many friends and acquaintances, so maybe a print wall is better. Pick a picture each month, print it 7×5, frame it in a borderless glass frame and put it on a wall. Gradually of course the wall will fill, so when it has reached capacity recycle the space, removing the older ones and putting up the newer ones.

You could go for one of those electronic frames, which can store hundreds of shots and cycle through them in sequence or randomly, but people don’t look at them, whereas they will look at the ones on the wall. And if you really want to make an impression, pick one picture each year and make a large print of it, A2 size or A1 size, and make a feature of it. Most of us won’t have wall space for many this size, so take down one at the end of the year and give it to someone who as admired it during the year.

By now you are maybe wondering how this will improve your photography. It is through the discipline of picking just one picture a month, or one picture a year, out of the many thousands that you take. You will learn to become more critical of your work, and to see which shots worked and which didn’t, and this will inevitably lead to you becoming a better photographer.

My photo wall

My photo wall

after noise reduction with Noise Ninja

after noise reduction with Noise Ninja

Jervis Street Centre. ISO 5000

Jervis Street Centre. ISO 5000

In the old days, once you had chosen your film and put it in the camera, you were restricted to that sensitivity setting until the film was finished. It was possible to change film part-way through a roll, but so awkward that most never bothered. Then dawned the digital age, and the sensor’s sensitivity could be changed as easily as the aperture or the shutter time. Early digital SLRs had a fairly limited ISO setting range, and once you strayed above ISO 400 or so the noise was very noticeable. More recent cameras have a much larger range – up to 54000 and more – and the noise is quite tolerable at the higher settings. And when there is noticeable noise post-processing software can do a good job of removing it.

Having a wide range of useable ISO, selectable shot-by-shot, extends the possibilities in low-light conditions. Instead of varying aperture and shutter time to get the exposure we can now juggle with sensitivity as well without being afraid of noise. Where previously you would have had to use flash, or a tripod if the subject was static, now you can quite happily boost the ISO and still have a reasonable depth of field (aperture) and exposure time. Indoor photography has never been the same.

Camera manufacturers have long offered equipment with the semi-automatic modes Tv and Av. Tv lets you set the desired shutter time and the camera will choose a matching aperture, while Av lets you set the aperture and have the camera select the shutter. Now there is a new semi-automatic mode TAv, where you can set both the aperture and shutter time and the camera will vary the ISO to match. This is ideal in, for example, street photography, where the light conditions are constantly varying as differently-dressed people pass through your target area but you want to keep the speed and depth of field under control. It is also great indoors, in the theatre or places such as museums where flash is just not an option. My Pentax allows ISO up to 54000, and can give quite useable pictures up to about 30000. Where previously I most often used the Av setting, nowadays my preferred setting is TAv.

Variable sensitivity extends your photographic options – take advantage of it.

Moiré Pattern

Moiré Pattern

If you look through something with a fine pattern on it, at something with a fine pattern on it, the two patterns may interfere and show a moiré pattern. Take, for example, some muslin cloth and a brick wall and try it for yourself. But the sensor of your digital camera is a fine pattern of light-capturing cells, and if you use it to capture something with a fine pattern there is a danger that the resulting image will show the moiré pattern that isn’t really there.

Now, the nice folk that design digital cameras really don’t want them making pictures with things in them that aren’t really there, so in front of the sensor they put a device called an anti-aliasing filter. This filter scatters – blurs – slightly the light, enough to stop moiré being captured in most cases. This is good, as it is very difficult to properly remove moiré in post-processing. But it is also bad, as it means your digital images will never be quite as sharp as film images of the same scene.

This is why you should ALWAYS sharpen your photos before letting anyone see them, as the sharpening process makes them look more like film, though it can’t restore the fine detail that is lost in the blurring process.

You may have noticed that some camera manufacturers have introduced versions of their high-end cameras with the anti-aliasing filter removed – and of course are charging more for the privilege. What is happening is that as the pixel count is going up, and the pixel spacing is decreasing, so the cases where the image source will interfere with the sensor to produce moiré are fewer. They are most likely to occur in fashion or architectural photography – things with fine patterns in them – so the manufacturers are offering a choice of cameras without the filters for those that work in landscape, nature etc. In practice, of course, unless your lenses (and technique) are really top of the range you may not see the difference.

Shirt photo from http://canoncanada.custhelp.com/app/answers/detail/a_id/2269/~/the-moire-effect

Centre weighting, exposure locked with focus

Centre weighting, exposure locked with focus

What exposure setting do you use? Most SLRs offer a choice of at least three – matrix, centre weighting, and spot. Often the matrix setting will give satisfactory results, though if the background is brighter than the subject it can leave the subject over-exposed unless you use fill flash, but fill flash is a different topic. With a bright background I prefer to use centre weighting or spot, and now we have the problem that both of those evaluate on the centre of the scene, and often our subject is not at the centre of the scene.

But just as last week we saw that we can lock the focus on the subject, then reframe before taking the shot, we can also lock the exposure. One way is to point the camera at area that we want optimally exposed and press the exposure lock button. The exposure settings will then remain unchanged until the next time the shutter is released. I generally use this when taking a bird on a branch. The bird will be relatively small in the frame, and seen against the sky, so even with spot exposure it is likely to be under-exposed, so I point at the trunk of the tree, lock the exposure, and reframe to take the bird. Of course, most times the bird will have flown by then, but sometimes you get lucky.

The other way is more useful if your subject is relatively large – a person, for example – and off-centre, as they probably should be. Since you will be using focus lock on the subject, you set your camera to lock the exposure automatically when it locks the focus, so that both are locked on the subject before reframing to take the shot. You may need to use the custom settings in your camera’s menus to tie the aperture lock and focus lock together, but you will be pleased with the results.