23 December 2013

PASM - Which to use? Shutter Speed Priority - A Tutorial

Shutter Speed Priority – A Beginner’s Guide

In this, the second of my beginner’s guides, I explain the principles of Shutter Speed Priority mode, marked as “S” for Shutter or sometimes “TV” for Time Value, on the camera’s mode dial. Whether you use a film camera or a digital camera, the basic principles are the same but for the purposes of this article I will presume the use of a digital camera of either the single lens reflex type or the non-reflex type.

The shutter speed is the duration of time that the light is allowed to strike the sensor, controlled in fractions of a second, each progressive setting giving half (or double) the duration of the previous setting. Here is the shutter speed progression table in one EV steps: 1/15 - 1/30 - 1/60 - 1.125 - 1/250 - 1/500 - 1/1000 - 1/2000 - 1/4000 – 1/8000 etc. The shutter duration setting may also, as has been pointed out in a reply to my previous article, also extend to whole seconds, minutes or even hours, depending on the circumstances.

The "aperture" is the "f" stop or "f" number. It is the opening in the iris diaphragm in the lens and controls the intensity of light (or the brightness of the image) passing through the lens to the sensor. Each progressive f number allows double (or half) the amount of light to pass through the lens. Here is the table of progressive f numbers:
f/0.7 - f/1.0 - f/1.4 - f2.0 - f2.8 - f/4.0 - f/5.6 - f/8 - f/11 - f/16 - f/22 - f/32 - f/45 - f/64 etc.

I had taken the train into London Town one afternoon and found myself in the vicinity of Petticoat Lane. Being a nice sunny autumn day I was equipped with my “street” kit, which is a Nikon D7000 body fitted with an AF Nikkor 35mm f1.8G prime lens. I prefer this combination for street photography because it is very lightweight, small and unobtrusive. On my APS-crop sensor camera the 35mm focal length gives the equivalent field of view of a 52.5mm lens on a full frame camera which is near enough to 50mm as to make no difference and suits my style of street photography very well.

I always keep a lookout for colorful buildings or good street graffiti and I happened to come upon a restaurant with very colorful security shutters over the windows. Being mid-afternoon, the place was not yet open for business and the shutters were still pulled down. They were painted to resemble market stalls, and each of the four was a different, vibrant, colour. Even better, the building opposite had stone stairs going up to its entrance doors which allowed me a good vantage point to photograph the restaurant window shutters. While I was contemplating the scene, I noticed that there was a cycle lane running past the restaurant along which a steady stream of cyclists passed. Most cyclists in London wear high-visibility jackets and helmets, and the strident colours of these jackets were contrasting wonderfully with the bright colours of the shutters. I wanted to use the cyclists as part of my composition and at the same time convey the movement of the cyclists across the scene.

To do so I would have to introduce a certain amount of blur or “subject movement” to the cyclists, in the direction of their travel. I would have to keep the restaurant facade and the rest of the scene pin sharp. I had no idea how fast the cyclists were actually travelling, I did not have a tripod, there was no convenient mailbox or lamp-post to rest my camera on, therefore some experimentation was in order. I set the ISO to 200, which is my personal “default” setting for colour, street shooting. I’m sure that the Nikon D7000 is capable of virtually noiseless images at higher sensitivity settings, but this was November 2011 and I had not had the camera long enough to be sure. I have one rule when out with a camera – never “presume.” I also had a nice big print in mind, and I wanted it to be as good as possible. I set the mode to “S” for Shutter Speed Priority which would enable me to select a suitably slow shutter speed to show subject movement in the bicycles. The question was, how slow a shutter speed could I set without sacrificing sharpness in the rest of the scene?

There is no VR or IS (image stabilization) feature in the Nikon 35mm f1.8G lens, nor is there in the camera body, so to give the camera some stability I sat on the steps opposite and rested my elbows on my knees. I chose a height on the steps that gave me a viewpoint parallel to the building opposite. This meant that I could keep my camera as parallel to the ground as possible resulting in minimal perspective distortion. I focussed on the facade of the building opposite and composed the image. There was a traffic sign on poles in the middle of the scene that was quite distracting, so if possible I needed to place a cyclist in front of the poles to “hide” them as much as possible. I included the doors of the restaurant on either side and a strip of the grey tarmac road in the foreground to act as a neutral foil to the bright colours of the window shutters. I quite liked the magenta traffic lane markings that matched the colour of the window second from the right. I decided to try a shutter speed of 1/60th at which speed the camera selected an aperture of f/12 with the metering set to center weighted. This wasn't going to be easy!

It was a case of waiting for a cyclist to come by while holding the camera perfectly still and trying again and again to get the shot! If I had panned the camera (followed the cyclist) I would have had a sharp cyclist and a blurry background. I wanted the opposite, a sharp background and a blurry cyclist. After half a dozen or so attempts I decided to increase the shutter speed to 1/90th, just to compare the difference in subject movement blur, and that was when I managed to release the shutter at the “definitive moment” when one cyclist came past, dressed in hi-viz jacket, and travelling at quite a rapid rate, and I captured him perfectly in front of the traffic sign poles. The exposure was 1/90th at f9.5, ISO 200, focus mode AF-A , 3D tracking, back button focusing. I could have used manual focus, but back button focusing has the same effect, as the focus will not move once I release the button and this is my default focus method.

I had the Jpg image quality set to large Jpg normal, picture control Vivid with saturation +3 because I wanted the colours to “pop.” I downloaded into Lightroom in my usual way (see this previous post:  http://grahams-word.blogspot.co.uk/2013/09/pasm-which-to-use-tutorial.html ) I opened the Jpg image in Photoshop CS5, created and saved a master Tiff file, re-sized it to 1024 pixels across, converted the colour space to sRGB, sharpened it for the web, applied my watermark, saved it as a 96dpi Jpg file at quality setting 6 and that’s the image you see here. I did not use the RAW file as there was no need.

Shutter speed priority comes into play whenever subject motion has to be either frozen or shown as a motion blur. When photographing soccer on a bright day with a 70-300mm lens, (that’s the game where everybody runs around chasing a big round ball and tries to kick it between the opposing team’s goal posts) I set the mode to “S” for “Shutter Priority” , I set a shutter speed of 1/2000th and ISO to 400. Thus the camera selects an aperture of around f/8 which results in sufficient depth of field to get the players sharp while isolating them somewhat from the background. The shutter speed of 1/2000th is fast enough to freeze the action.

When photographing birds in flight (or BIF as I have been educated into calling it) shutter speed priority is a must in order to freeze the bird in flight. Depending on the speed of the bird, the distance and my panning ability, I set a shutter speed of between 1/500th and 1/2000th with ISO on 200 auto and plus one EV compensation if I am shooting against the bright sky. I will not go into all of the other parameters of BIF photography here.

Another subject that requires shutter priority mode is motor sport. Photographing racing motorcycles or racing cars from the track-side requires a good understanding of shutter priority mode and a practised skill in being able to pan the camera to maintain a rapidly moving subject in the correct place within the frame to make a pleasing composition. Good panning technique will “absorb” the motion of the subject to a certain degree, and the slower the shutter speed, the more the background will blur. Choosing a shutter speed that results in a nicely blurred background while keeping the subject pin sharp while you pan the camera, is a learned skill, but once learned, can result in spectacular photographs.

Remember the exposure triangle – 1) Aperture, 2) Shutter speed and 3) ISO sensitivity. To maintain equality, If you adjust any one of them, one other must be adjusted accordingly to compensate.


Shutter release mode:

Why didn't I set the camera on multi-shot, burst mode and just hold down the shutter release while a cyclist came by? Well, I could have, but what would have been the challenge in that? Besides, I’m “old school” and I resent the fact that the camera can probably out-think me at every turn. Using single shot, I had to compensate for the shutter lag (the delay between pressing the shutter release and the shutter actually firing) which is always good training.

Why did I use center weighted metering?

I could have used matrix metering, but I find that I get more consistent results using center weighted metering with the Nikon D7k. In matrix metering mode, the metering uses not only the brightness of the various parts of the scene, but also the brightness and colour of the subject identified by the auto-focus point. I used back button focusing, single point 3-D tracking, therefore, in matrix metering mode, the colour and brightness of whatever was under the center focusing point at the instant that I pressed the “focus on” button would have influenced the exposure. I personally don’t like this feature as I think that it introduces a degree of inconsistency to the matrix metering. Just my opinion.

Picture control – picture style:

Why did I use “Vivid” picture setting with additional boost of saturation? I wanted the colours of the window shutters as well as the high-vis jackets of the cyclists to really “pop” against the fairly dull background. The default “Vivid” setting on the Nikon D7k isn’t vivid enough for the result that I envisaged. I also had the RAW file to play with if I didn't get what I wanted from the Jpg. As it turned out, the Jpg file was right on the button. Incidentally, I don’t think that this image would have worked in monochrome (B&W) at all.

Graham Serretta
London 2013.

6 November 2013

The Nikon Df

A Dream Come True

I prepared the following a month ago, but haven't posted it to this blog yet.  Then yesterday, Nikon announced their Df  digital SLR camera!  It's as though they read my mind.  Here's what I wrote:

I want a camera that......

Is a "full frame" 24x36mm DSLR, with an optical mirror box viewfinder and instant return mirror, with a viewfinder image coverage of 100% and a magnification of 95% and an eyepiece relief distance that allows the user to wear glasses and still see the info bar at the bottom of the viewfinder screen.  The viewfinder should be purely mechanical i.e. it should not have a "live" LCD overlay screen as used by Canon in the 7D/5D and should be just like an Olympus OM1.    It should have interchangeable focussing screens.  There should be NO movie capability whatsoever!

I want a camera that is the size and weight of a Nikon FM3n and has the build, finish and ergonomics of a Pentax K3.  I want a camera that has NO movie capability whatsoever.   I want a camera that has the rear LCD screen of the Nikon D7100, articulated to allow high and low level viewing with automatic brightness according to the ambient light.   I want a camera that has the Canon rotating command dial on the rear with a "Set" button in the centre.   My camera should have a top LCD screen on the right, looking from the rear, and a locking, mode dial on the left, concentric with a shutter speed dial.  The mode dial should allow a choice of Av, Tv, M and with user programmable  modes P1, P2 and P3. and no more!    The shutter speed dial should allow the selection of speeds from 1/4000 down to 1 sec and B, and have a green "Auto" setting.  "Auto" mode would over-ride the mode setting and take control of all exposure settings, metering, drive mode and auto focus settings, as well as set Jpg picture capture only.   The shutter release should come from a Pentax K5 and have DOF preview combined with the on/off switch around the shutter release button.   It should have dual SD memory card slots (because the pins of CF card slots are too fragile and prone to fault).   There would be only one control dial, below the shutter release button in front.  This front dial would control the aperture setting  IN ALL MODES!  In all modes except "M" mode, the rear command dial (the big one next to the rear LCD screen) would set the exposure compensation, by default.

In an ideal world, the lens mount (and here I admit I have a quandary) should be Nikon F.   However, I would prefer the aperture actuation to be electronic and not by means of a mechanical lever and spring mechanism, which contributes to vibration, harmonics and shake at the instant of exposure.    That restricts the choice of lens mount to Canon EF as things stand at the moment.   No bad thing as the range of Canon lenses is superb, and the "L" lenses are built tough.

  I want a camera that only has (5) buttons on the left side of the LCD, as follows:

Top left, within easy reach of my left thumb - > (Display) - Pressing this once displays the last image taken.  Pressing the (i) info button (see below) repeatedly while the last image (or any image) is visible cycles through the image information display modes:  Image only, Large histogram superimposed across the bottom of the image as per the Pentax D5, EXIF and Meta data displayed alongside and below the image and multiple RGB and luminance histograms displayed alongside the image. 

ISO - pressing this will show the range of ISO sensitivities on the LCD screen.  50, 100, 200, 400, 800, 1600 and 3200.  Rotating the rear command dial will highlight each in succession and pressing the "Set" button will set the chosen ISO.  There will be no selectable  "Auto" ISO setting.  The selected ISO should be displayed in the top LCD screen, as well as in the viewfinder.

WB -(White Balance) - Pressing this should bring up a choice of white balance settings the same as a Canon 1/5/7 D.  Rotating the rear command dial should highlight each option and pressing the "Set" button will select the chosen option.   There should be a "custom" option which should only require that an image of a mostly white or grey subject be captured while this option is highlighted, to set the white balance accordingly.  An icon indication the set WB should be displayed in the viewfinder and on the top LCD.

Dr - (Drive) - Pressing this should display a list of the drive modes on the rear LCD.  These should be S (Single shot),  Cs (Continuous slow), Cf (Continuous fast) R (Remote)  RMU (Remote Mirror Up) Q (Quiet).  The option to set a delay of 2 or 10 or 30 seconds when using the remote, either IR or wired, should be available on the remote controller itself.  Drive mode should be selectable electronically, NOT mechanically by a dial a' la' some Nikon cameras, so as to allow for the drive mode to be programmable within P1, P2 or P3.

Ps - (Picture Style) - Pressing this should display a choice of the usual Jpg picture styles i.e: Standard, Vivid, Portrait, Landscape, B&W.  Selecting B&W and pressing the "Set" button should display the options for B&W filter simulation, i.e: Yellow, Red, Orange, Geen and None, with None as the default.

Immediately above the command dial and to the right of the rear LCD screen there should be an "Info" (i) button.    Pressing this once should display a "Quick Control Screen" as per the Canon 5/7 D cameras.  This should show all of the basic exposure settings in grid layout.  Rotating the command dial would highlight each setting in sequence, pressing the "Set" button once would display a list of the options for that particular item, again, rotating the command dial would highlight each option in turn,  and pressing "Set" again would select the highlighted option.  Items in this screen should include battery condition, card slot allocation (Jpg slot 1, RAW slot 2, backup or overflow,  image number, file name, copyright data and shutter count.  There would be no menu containing reams of custom functions or any other settings.  There would be no post capture editing or effects filters.

Beneath the "Info" button would be a "LV" live view button.  This would initiate live view for image framing and critical focussing purposes.  I include this feature as I know that many macro enthusiasts use live view as well as others, although I rarely use it.  

On the top left of the prism housing, there should be a "Qual" button to select the Jpg image size, compression and RAW file recording, used in conjunction with the command dial.   Options should be displayed on both the top and the rear LCD screens. 

On the lower left of the mirror box there would be a button to set the AF mode, used in conjunction with the command dial, and incorporating a switch to disengage the auto AF.  On the back of the camera, top right and positioned to fall beneath my right thumb, there should be an "AF-On" button to initiate the auto-focus i.e. permanent back button focus.  The only time this would be disabled and auto focus initiation given to the shutter button would be when "Auto" mode was selected.   Alongside this button, and recessed to a lower level, would be an auto exposure lock button (* or AEL). 

On the top plate, in front of the top LCD screen, there should be a button to access the metering mode, used in conjunction with the rear command dial.  Modes should include Matrix, Centre weighted average and 2 degree spot.  Alongside this should be a "Green" button, Pentax style,  pressing which should set the exposure when using OEM or non-communicating lenses.  On the front, between the mirror box and the grip, would be a "RAW" button, pressing which when picture quality is set to Jpg only, would result in the capture of a RAW file.

There would be no "menus" or screen after screen of custom functions.  It would be more camera and less electrical appliance.  The shutter would have a nominal life of 200 000 actuations.

Connectivity would include a live feed for tethered viewing of live view or captured image playback on a tablet,  (with the necessary  software supplied on a CD) as well as a USB port for connection to a PC or laptop and a wired remote control 1.5mm socket.   Built in Wi-Fi connectivity as well as built in GPS data would be provided.   There would also be a "universal" 12 volt DC power supply input which would also serve to charge the battery when connected.

There would be a built-in AF assist lamp which would double as an off-camera IR flash commander and  trigger.  There would be no built-in pop-up flash.  The battery would give at least 900 exposures without using live view.  There would be a battery grip capable of taking six AA batteries or two Ni-Mh batteries shaped like the grip for the Pentax K5.  Image stabilization would be built in to the sensor, as would auto levelling and dust removal.  Image stabilization would also be available as a lens feature.  A Quick Menu Screen item would allow sensor stabilization to be deactivated.  Neck-strap attachment would be by traditional lugs, not slots.  However, there would be provision for the attachment of a hand-strap on the right side without requiring the attachment of the battery grip.

So, Mr Canon, do you have what it takes.........?

Well, Canon haven't come to the party, but Nikon certainly have.  The Nikon Df answers most of my desires, and I predict that demand will outstrip supply.  

Bravo, Nikon and Thank You!

14 September 2013

PASM - Which to use? A Tutorial

Here's my take on the various exposure methods that I use and the circumstances in which I use them.  In this first piece I'll tell you the story of how this image was taken, using "A" or "Aperture Priority" mode:

The "aperture" is the "f" stop or "f" number.  It is the opening in the iris diaphragm in the lens and controls the intensity of light (or the brightness of the image) passing through the lens to the sensor.  The term "stop" comes from the days of plate cameras when the aperture was a metal disc with a hole drilled in its centre that was dropped into a slot in the lens and thus "stopped" the light according to the size of the hole.  The "f" number is the ratio of the diameter of the aperture to the focal length of the lens.  Each progressive f number allows double (or half) the amount of light to pass through the lens.  Here is the table of progressive f numbers:

f/0.7 - f/1.0 - f/1.4 - f2.0 - f2.8 - f/4.0 - f/5.6 -  f/8 - f/11 - f/16 - f/22 - f/32 - f/45 - f/64

The shutter speed is the duration of time that this light is allowed to strike the sensor, controlled in fractions of a second, each progressive setting giving half (or double) the duration of the previous setting.  Here is the shutter speed progression table in one EV steps:  1/15 - 1/30 - 1/60 - 1.125 - 1/250 - 1/500 - 1/1000 - 1/2000 - 1/4000

There is a little stream flowing through a stand of trees through which fields and hedgerows are visible, that I wanted to photograph.  Laden with tripod and camera bag, I managed to cross the stream without falling in.  I had been there before and had returned on a number of occasions to view the scene at different times of the day and in different seasons, to decide on the best conditions in which to capture the scene.  I didn't want the light too harsh, which would have been the case if the sun were overhead, so I chose mid morning when the sun is at an angle to the trees and penetrates into the clearing where the stream is visible.  This also meant that the trees were back-lit with the reflection from the water providing some fill light.

I set up the camera on the tripod, fitted with a 35mm equivalent lens and connect a remote shutter release.  Why a tripod?  Because I wanted maximum sharpness combined with maximum depth of field and the least noise.  Let’s take those one at a time.

Maximum sharpness means no image blur caused by camera movement and precise focusing. The tripod and the remote release will eliminate camera movement.  Maximum depth of field means that I want everything in focus from the foliage lining the bank of the stream immediately in front of me, right through to the distant hedgerows and trees on the horizon.  I will therefore need to use a small aperture or f-stop (a big f-number) such as f/16 or f/22 and I will need to set the focus distance so that the far limit of the depth of field falls on the distant horizon and not beyond it.  This will ensure that the near limit of the depth of focus falls as close to the camera as possible.  The lens will therefore have to be focussed at the "hyperfocal" distance for the aperture that I am using.  I choose to use f/16. 

I don't use f/22 because I know from researching the test results of the lens I am using that diffraction effects will reduce the sharpness of the image at apertures smaller than f/16.  I find the hyperfocal distance from a handy app on my iPhone, but I also carry a small chart that I can use.  The lens is also marked with a scale as it is a prime lens.  If you only have a zoom lens with no such markings, you should focus one third of the distance into the scene, and take at least three shots at slightly different focus settings.   Least noise means that I will have to use a low ISO sensitivity setting, as the higher the ISO, the more noise there will be in the image, especially in the shadows.  The lowest ISO that my camera can be set to is 100. 

With ISO 100 set and the camera in "A" or Aperture Priority mode with the aperture set to f/16 and the exposure meter set for spot reading, I take three readings, one of the sky above the horizon, the brightest part of the scene, one from the sun-lit grass on the far bank of the stream (the area that I want to be a mid-tone) and one from the shadow under the tree branches on the right of the scene.  Aperture priority mode locks the aperture at my chosen setting of f/16. The sky reads f1/2000th, the grass reads 1/125th and the shadows read 1/15th.

The mean aggregate reading was an exposure value of 1/125th at f/16 which is the centre of the dynamic range of the scene, which covers seven EV (Exposure Value) steps.  (1/15th to 1/2000th).   At an ISO of 100 and a aperture of f/16 a shutter speed of 1/125th would give me an exposure that would place the sky at the extreme right hand side of the histogram, or off of the toe of the density curve, resulting in some loss of highlight detail and the shadows at the left hand end, or at the peak of the density curve, provided that the camera's sensor was capable of recording the full 7 EV range, which most are.  However, in order to drag the entire brightness range down at least one EV, in order to avoid clipping of the highlights, I decided to shift the exposure to 1/250th at f/16.  This placed the highlights just inside the extreme right-hand  limit of the histogram and brought the sunlit grass to a more comfortable, slightly darker mid-tone position while blocking up the shadows, but only in the Jpg.  I knew that there would still be plenty of shadow detail available in the RAW image file that could be extracted in Lightroom.

I therefore set an exposure of 1/250th at f/16 at ISO 100 and wishing that a nice big Blue Heron would come along and land on the bank of the stream, I exposed three images, bracketed at -1EV, zero and +1EV, in RAW + Jpg.

Back at the coal face, I converted the RAW file to DNG and re-named it with a prefix denoting the camera type, during import into Lightroom, when both the RAW and the Jpg files are saved to primary and backup drives.  I then applied the usual preliminary adjustments such as exposure, brightness, contrast and white balance, and applied the lens profile correction tool to correct any lateral chromatic aberration or fringing before opening the image in Photoshop CS5.  I then adjusted the levels slightly, and used the “Shadows & Highlights” tool to lighten the shadows until I could just see detail in the foliage.  I also applied a small amount of highlight recovery, just to be sure that nothing was blown out in the sky.  A little colour saturation, a small amount of unsharp mask, and I saved the file as a Tiff in my “Master Files” drive, adding “Master” to the file name, again backed up on an external drive and also transferred to my cloud archive in Dropbox.  I then created a sharpened file suitable for printing an 11 x 14” print at 300 dpi complete with watermark and imbedded AdobeRGB colour space profile,  and saved this as a Tiff file with the word 11x14pr added to the filename, in my “Prints” folder.  I then reverted to the master file and created a 1024 x 756 pixel Jpg file at 96 ppi, watermarked, compression 6, sRGB colour space, sharpened, for web use which I saved in my “Web” folder as well as in the cloud, with the word “Web” appended to the file name.   This is the file you see here.  The master file was also used to create a 24 x 36 inch print file,  without watermark,  for exhibition use. 


  • Could I have hand-held the camera? 

Probably.  Even at a shutter speed as slow as 1/60th, you should have no problem taking a sharp shot provided your camera holding and your shutter release techniques are good and well practised.  I always remind myself that, in the days when cameras only had two shutter speeds, 1/60th and "B", millions of people got sharp shots by learning to hold the camera steady and release the shutter without jerking.  If you have one of the new lenses or cameras fitted with image stabilization you should have even less problems.  I often take three bracketed shots indoors, handheld, to make an HDR image, where tripods are not allowed, using a VR lens and I get sharp results.  It just takes a very steady hand!  If, however, you intend printing the image larger than 8 x 12 inches, I strongly recommend that you use a tripod.

  • Could I have used the camera's exposure meter set to matrix metering?

Probably.  A matrix meter would, in my opinion, have underexposed the scene, but you could have taken a number of shots with varying degrees of exposure compensation dialled in and viewed the histograms, until you got the exposure that you wanted.  I shot this in RAW because I knew that I could extract greater detail out of the shadows if necessary, without blocking out the highlights.  The dynamic range is just on the limit of a Jpg file's capability unless you are adept at adjusting the in-camera picture control settings (contrast, sharpening and saturation).

  • Could I have used a polarising filter?

Absolutely yes!  I didn't use one simply because I forgot to bring one along, but if I had used a CPL, I could have deepened the blue of the sky nicely and improved the surface of the water at the same time by eliminating some of the reflection.  Note that a polarising filter would absorb 2 EV of light and I would therefore have had to expose the above image at a shutter speed of 1/30th, making a tripod mandatory.

  • What about the white balance?

I left the WB set on "Auto" for this shot, but to some, it is a little cold as it came from the camera.  However, if I tweak the RAW file's WB to be ever so slightly warmer by setting it to "shade", I lose the saturation of the greens in the grass, which also affects the grass in the sunlight (my mid-tone).

  • Could I use my kit zoom lens?

Yes, set at a focal length equivalent to 35mm on a full-frame camera.  That means around 24mm on an APS sensor sized camera.  The label "Kit lens" has resulted in the image quality of these lenses being regarded as inferior.  This is not always true as the camera manufacturers would not supply their latest high-tech camera with a lens that would not impress the purchaser with the quality of the images.

There are a number of so called kit lenses that have superb image quality, two of my favourites being the ubiquitous Nikon AFS Nikkor 18-55mm f3.5-5.6 VR II DX and the Canon AF-S 15-85mm f3.5-5.6 IS USM.    How do I set the focus distance if I don't have any markings on the lens - can I use the preview button?  The Depth of Field preview button will close the lens aperture to the aperture set for taking the image.  This results in a darkening of the image on the focusing screen in the viewfinder making it very hard, if not impossible to judge the sharpness of the different parts of the scene.  If you have live view, you should use that instead, and use the magnify button to check sharpness.  You can also use the rear LCD screen to preview a test image, and use the zoom function to zoom into the image and check for sharp focus at various places in the scene.

Next time I'll give an example of using "S" or "Shutter Priority" mode.

Remember, it's all in the light!

Graham Serretta
London 2013