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//-->A PHOTOGRAPHER’SGUIDE TONever take a blurred image again with thisessential guide to capturing crystal-clear photosSharperShotsFREE WITH ISSUEShutter speed and supportUse these simple techniques and tips to beat the shakesTShutter speedand focal lengtho capture sharp shots handheld, yourcamera shutter speed needs to be fastenough, and the focal length of your lensplays a big part in determining how fast it should be.The effects of camera shake are magnified at thetelephoto end, so you’ll need faster shutter speedsat longer focal lengths.A good rule of thumb is to shoot at ‘one over’the effective focal length (EFL) of your lens; so, forexample, an EFL of 300mm requires a speed of atleast 1/300 sec. If you shoot with an APS-C sensorcamera, you’ll need to take into account the cropfactor, which is 1.5 for Nikon cameras and 1.6 forCanon. Multiply the crop factor by the lens’s focallength to calculate the EFL. So if you’re shootingat 300mm on a Canon APS-C body, for example,300 x 1.6 = 480, so a 1/500-sec shutter speedshould give shake-free shots.IUp the ISOf you’re shooting handheld in low light, or capturingaction shots of fast-moving subjects, you may findthat you can’t select a fast enough shutter speed toget sharp shots, even at wide aperture settings. Theeasiest solution is to increase the ISO. While newer SLRsoffer excellent low-light performance, you may have tocompromise a little on image quality. If you increase yourISO from 100 to 1,600 you’ll gain an extra four stops: ifyou lock your aperture, that will increase your shutterspeed from, for example, 1/15 to 1/250 sec.Image stabilisationn increasing number of lenses feature some form of imagestabilisation system, which enables you to shoot handheldat up to three or four stops slower than would be possiblewith a non-stabilised lens. Canon calls this feature IS (ImageStabilisation), while Sigma labels it OS (Optical Stabilizer) andTamron calls its system VC (Vibration Compensation). Stabilisationis a great feature to have when you’re shooting in low light or whenyou want to freeze action, as you can drop your shutter speedfrom, for example, 1/15 sec to 1/250 sec. Some lenses includea stabilisation system with two settings, to compensate for bothvertical and horizontal movement.AFrom the makers ofDigital CameraGet creative withshutter speedRules are made to be broken. You can getcreative by using slow shutter speeds toblur some or all of an image. When you’reshooting cyclists, motorsports or other fast-moving subjects, you can pan the camera tofollow a subject, and keep it sharp while blurringthe background to create the impression ofmovement. You can also create painterly effectswith a technique called camera-dragging. Set yourshutter speed to 1/30 sec to start with, then movethe camera during the exposure to turn subjectssuch as trees into abstract streaks of colour.lack and white is great for portraiture:by eliminating colour, you can hide skinblemishes and spots, and withoutcolour to distract the eye, you’re instantlydrawn to the subject’s face and expression,which in turn convey character. If there aredistracting colours in the background, a monoPractise your panning technique, andconversion will helpfully tone these downyou’ll soon be able to freeze fast-movingwhile boosting contrast in your subject.objects while blurring the backgroundBB&W can be best!You’ll find the Mirror Lockupfeature in your SLR’s CustomFunction menuss well as the camera-shake that can be introduced if youhandhold the camera at slow shutter speeds, shots takenwith SLR cameras can also be blurred by slight internalvibrations as the mirror flips up and down. If you use long telephotolenses, or shoot extreme close-ups or long exposures, the tiniest ofmovements will be magnified – and even if you use a tripod, you can’teliminate vibrations completely.The solution is to enable mirror lockup, where the mirror flips upwhen you press the shutter button; you press the button again totake the shot, after which the mirror flaps down. If you don’t have thisfeature, use Live View; the mirror is locked up while this is enabled.AMirror lockuphen you’reshootinglandscapes inlow light, and using narrowapertures to maximisedepth of field, yourshutter speeds are likelyto be too slow to shoothandheld. A tripod willhelp you get sharpershots, but simplymounting your cameraon one may noteliminate all movement;you need to make surethe tripod is as stableas it can be. Extend thetop leg sections first,as these are sturdier,avoid raising the centreon’tcolumn if you can. Don’t touch the camera or tripod during theexposure: use a remote release or the self-timer to fire theshutter, and enable Mirror Lockup or use Live View. On windydays, hang your kit bag from the centre column (there’s a hookfor this on some models) to weigh down the tripod.WTripod setupFrom the makers ofDigital CameraAperture, focal length and your lens all affect what’s in focus in shotsF/5.6 AT 100MMIt’s not just aperture that affects depth offield: a longer focal length means that thedepth of field is shallowerMaster depth of fieldF/5.6 AT 24MMIAperture anddepth of fieldn simple terms, the smaller theaperture is, the greater the depthof field is. So if you’re shooting alandscape and want to maximise thedepth of field to ensure the whole ofthe scene is sharp, for example, you’dselect a narrow aperture, ideallybetween f/16 and f/22. Tocompensate for the smaller aperture,which won’t allow as much light toreach the sensor, you’ll need a longershutter speed to capture a goodexposure, so in low light you’ll needa tripod to support your camera.If you want the background to beout of focus – to make a portraitsubject stand out, for example – you’dselect a wide aperture, such as f/2.8or f/4. As well as portraiture, thisaperture range is ideal for wildlifephotography, or any situation whereyou want to lift your subject out oftheir background. The larger apertureopening allows more light to reachthe sensor, so you won’t have tocompromise on shutter speeds,enabling you to shoot handheld evenin low light conditions.DDepth of fieldand focal lengthepth of field is also affected by focallength. If you shoot with a wide-anglelens, you’ll capture a broader depth offield, which keeps the scene sharp from frontto back. For example, at f/5.6 on a wide-angle 24mm lens, you’ll get a broader depthof field than at f/5.6 on a 100mm telephotolens. This is why wide-angle lenses are greatfor landscapes, while the shallower depth offield of telephotos enables you to isolate asubject you’ve zoomed in on, making themideal for wildlife.Zoom vs primehe quality of your lens canalso have a big impact onthe sharpness of yourshots. Prime (fixed-focal-length)lenses are optically superb, butthey’re relatively expensive and can be limiting interms of flexibility; zoom lenses generally offergreater versatility at lower prices, but at the costof some image quality.It’s best to avoid the extreme focal lengths ofa zoom lens, as optical performance tends to bepoorer at the wide and long ends. Another factorto consider is the maximum aperture available atdifferent focal lengths. For example, a 70-300mmf/4-5.6 lens runs from f/4 at the 70mm settingthrough to f/5.6 at the 300mm setting. As theaperture decreases, the shutter speed needs tobe slower to maintain the same exposure, whichincreases the risk of camera-shake.Prime lenses often have very wide maximumapertures, so as well as being ‘fast’ lenses – whichenable you to use faster shutter speeds in lowlight – they also have fewer lens elements, makingthem lighter and optically more precise. Thedrawback is that you may need to carry morelenses to cater for a range of shooting situations.TNARROW APERTUREWIDE APERTUREDDepth of field andwhere to focusepth of field decreases the closeryou are to a subject, so accuratefocusing is vital to ensure that yoursubjects are sharp. This is why you needto use narrow apertures in macrophotography. Even then, if you’re shootingextreme close-ups the depth of field mayonly be a matter of millimetres.As a rule of thumb, there’s roughlydouble the amount of depth of fieldbehind a focal point than there is infront of it. So, for example, ifyou were to shoot a landscapewith a narrow aperture andfocus at infinity(A)you’d lose alot of depth of field; by focusingabout a third of the way into theA - FRONT SOFTscene(B)you’ll get optimumsharpness throughout the frame.ABB - FRONT SHARPTFind the sweet spothe ‘sweet spot’ of a lens refers to the aperturethat will deliver the maximum sharpness acrossthe frame. A lens doesn’t produce the samelevel of sharpness throughout its aperture range, soby determining its sweet spot youcan ensure you capture the sharpest shots possible.The sweet spot is usually in the mid-range aperturesettings of f/8 to f/11, with sharpness tending to dropoff at the minimum and maximum apertures. So yourchoice of aperture not only affects depth of field; itplays a part in ensuring sharp shots. It’s best to usethe sweet spot for landscapes, and other situationswhen you want corner-to-corner sharpness.Use the optimumaperture for yourlens when capturingevery detail counts [ Pobierz całość w formacie PDF ]