Friday, November 26, 2010

Photography Basics

Drive and disclaimer:
  • I had time for blogging and I couldn't think of anything better to blog.
  • People started bugging me with same set of questions "What is Shutter Speed?", "How big should the aperture set for a portrait photograph?", "What is the ISO I have to use on a bright day?", "What white balance setting I must use?" etc. etc.
  • I've tried to explain whatever I know and in the easiest way I can think of, if you still can't understand you are either dyslexic or you're not meant to be a photographer :) Contact me for more comprehensive explanations to help you. sachin [dot] cas [at] gmail [dot] com
  • I'm planning to use some photographs of mine to give certain examples, but this is just a plan when I started the article and I don't promise that at the end of it. (Update: No am not doing it...instead I'm stealing some informative diagrams and photographs from internet.  None of the diagrams/photographs I've used here are mine.)
  • This article is not a bible for beginners and it won't make you a good photographer, it may just make you aware of few of the techniques and terminologies and probably you'll be in a position to decide what parameters to use for a particular shot.
  • There are lots of resources on the web, few of which I'm gonna scribble at the end of the article.
  • Anyway this article is potpourri of my experiences and loads of stuff collated from various resources.
  • Remember! The best way to learn is to keep clicking more photographs and keep seeing more photographs.
  • Remember again! I am an amateur photographer and a Canonian (digital only). My knowledge about other camera systems is very nominal, the article will be biased towards Canon system.

A dangerously brief history of photography:
  • Camera Obscura: The light from the scene passing through a pin hole and reflected by the mirror is projected onto a paper where the scene is traced. 10th Century.
  • Joseph Nicéphore Niépce produced the first permanent photograph by projecting on pewter plate coated with bitumen of Judea, exposing it for 8 long hours. 1825-27.
  • Louis Daguerre invented Daguerreotype and was able develop photos with just half hour exposure and found that by immersing in salt, the permanency could be maintained. 1833-39.
  • William Henry Fox Talbot invented Calotype, where in an negatives were made and could be used for reproducing prints. 1839-40.
  • George Eastman created film. 1884.
  • Kodak invented sensor (CCD) with mega pixels for recording images. 1986.
Daguerrotype of Boulevard du Temple in Paris, 1838 by Louis Daguerre

Types of Cameras:
  • Based on type of medium: Film, Digital
  • Based on size of the medium: Large format, Medium Format, 35mm, APS-C
  • Based on mechanism: Point and shoot (P&S), Single Lens Reflex (SLR), Twin Lens Reflex (TLR), Rangefinders,
  • Miscellaneous types: Single use cameras, Lomos, Panoramic etc.
Large format cameras are the ones which uses media larger than 4x5 inches. Most of the Polaroid cameras, view cameras come under this genre. If you see a person clicking a photograph with a cloth on his head using a machine with bellows, that's a large format camera. Large format cameras are generally bulky and cumbersome to use, hence it cannot be used for sports photography or any other photography genre which requires faster foucssing/clicking. Ansel Adams' greatest black & white landscapes have been shot using large format cameras.

View cameras a.k.a Large format cameras
Medium format cameras are less bulkier than large format ones...their media size is larger than 35mm film and smaller than 4x5 inches. They're more popular than large format ones and is mainly used by landscape and fashion photographers. Hasselblad and Mamiya are known for their medium format cameras. The digital ones bear a price tag that requires you to sell your dad's house along with his car and still ending up taking loan from the bank.

Hasselblad CM system (Medium format camera)

Most SLRs and film based P&S cameras in the market are 35mm cameras. The actual size of the 35mm medium is 24x36mm. The ubiquitous film rolls that you see in the market are all 35mm ones.

Pentax 35mm film camera

If your D-SLR is not a full frame (35mm) one, then it's most likely APS-C or APS-H sized sensor. To make things easy, read APS-C or APS-H size as a size slightly smaller than 35mm. You might come across terms 1.8x crop factor...which would simply mean the size of your camera's sensor is 1.8 times smaller than that of 35mm.

Sensor size comparison

Crop factor
Point-&-Shoot, sometime back, were simple consumer cameras with fixed focus point, fixed focal length...all you need to do is point and shoot. The recent digital ones come with variable focal length (zoom), advanced focus mechanisms, adjustable ISO and host of other features which can almost be called a fixed-lens-SLR.

An SLR like Point-&-shoot camera
SLR cameras, these days, are probably the most widely used cameras by amateur and professional photographers. It's easy to use, less bulkier than view cameras and it's usability is greatly extended by interchangeable lenses. The light entering through the lens hits the mirror inside the camera body, placed at 45 degrees inclination. The mirror reflects the incoming light vertically up to a pentaprism, which throws the light out of viewfinder. That's how when you see through a viewfinder, you see the live image and not an electronically processed one like on a digital P&S. These bulleted points below which I effortlessly flicked from, very easily describes the working of an SLR (Thanks to Philip Greenspun from whom I've learnt ABCs of photography).

Suppose that the photographer has chosen an exposure of f/8 and 1/125th of a second. Here is how most SLRs work during exposure:
  • lens is kept open to maximum aperture (e.g., f/2.8) for ease of viewing and metering
  • when the user presses the shutter release, the lens aperture is stopped down to the taking aperture of f/8. On old-style camera/lens interfaces (e.g., Nikon, Hasselblad), this is accomplished by moving a lever. With camera/lens interfaces designed in the 1980s (e.g., Canon, Rollei), this is accomplished by sending an electrical signal to a solenoid in the lens.
  • the mirror is flipped up out of the way of the light (and parked flat up against the prism)
  • now that the lens is stopped down and the mirror is up, the viewfinder blacks out, the shutter opens and light begins to strike the film
  • as soon as the shutter is fully open, the camera signals an electronic flash, if attached to fire
  • when 1/125th of a second has elapsed, the shutter is closed
  • the mirror is pushed back down to viewing position
  • the lens aperture is reopened to its widest setting 
How SLR works?

Twin Lens Reflex (TLR) cameras work pretty much on the same lines of SLR but just that it'll have two lens of the same focal length, one for capturing the photograph and other for the viewfinder (waist-level viewfinder).  Since there are two separate lenses there need not be a mirror-swinging action to actually capture the photograph which reduces the shutter-lag and also it won't black out the view-finder unlike SLR.  This is particularly useful in long exposure shot wherein the photographer can keep seeing the viewfinder.  The most famous TLR in the market is the German Rolleiflex TLRs, as far as my knowledge goes there is no digital TLR yet.

Rolleiflex TLR

    Rangefinder cameras are something I've never seen or used, so I wouldn't write much about it except that they're known for their precise, tack sharp focussing systems.  Read about it on its wiki page: Rangefinder cameras.  My greatest inspiration in the field of photography, Mr. Henri Cartier Bresson used 35mm Leica rangefinder camera with 50mm lens.

    Leica's latest Rangefinder in market

    Exposure: Shutter Speed, Aperture, ISO:

    Exposure is the measure of light falling on the media, be it film or CCD. It's controlled by three factors namely shutter speed (denoted by S or Tv), aperture (denoted by A or Av) and sensitivity of the sensor (ISO). Let me try to explain each of these to a greater detail.

    Shutter Speed is the amount of time the shutter screen remains open, in other words, it is the duration for which the light hits the media. Shutter speed is the feature of the camera and not the lens. Faster the shutter speed, lesser the duration for which light hits the sensor, so lesser amount of light is captured.

    The shutter speeds range from 1/4000th of a second (1/8000 on a pro camera) to 30seconds, with a special "B" (bulb) mode wherein the shutter could be kept open as long as the photographer wishes (of course, constrained by battery).

    The shutter speed controls another most important aspect - freezing the subject in time. Simply stated, you shoot a speeding car with slow shutter speed, you tend to see the trails of the car resulting from motion blur. On the other hand you shoot the same car with higher shutter speeds, the car will appear as though its stationary. In case you're wondering what magic, the photographer has done to capture those long trail of lights, the answer is simple: he would have just kept the shutter open long enough to capture the trails.

    When you're shooting with slower shutter speeds (under 1/100th of a second) holding the camera, it is highly likely that you end up with a blurred photograph. Why? It's obvious that when you're shooting at lower speeds, even the slightest camera shake will contribute to the blurring of the photograph. Solution for this problem is to mount the camera on a tripod or try to find a platform nearby to place the camera and shoot in case you're lazy to carry a tripod.

    The answer for the question "What shutter shutter speed to use for a particular shot?" is "It entirely depends on the kind of shot and it can't be generalized".   If you're shooting birds, wildlife, sports, street shots etc. which require the moment to be captured tack sharp use high shutter speeds.  Night shots, trail capture, abstract photographs, light painting, milky waterfall photographs etc. require slow shutter speeds.

    Shutter speed Vs Aperture

    Aperture is the feature of the lens and has nothing to do with the camera, except that the aperture values are set/controlled by the camera. As the name itself suggests, aperture is an "opening" at the rear end of lens through which the light enters the camera. Earlier days, the lens barrel had an aperture ring to set the required aperture values, but these days the aperture could be controlled by the knobs on the camera.

    The maximum and minimum value of aperture depends, as mentioned earlier, on the lens and not on the camera. You may find lens with aperture as big as f1 or f1.4 or as small as f45 or f64. I'm sure your immediate response to the stimulus is "What the 'f'???" f doesn't have too much significance, aperture is measured in terms of f-stops and hence the f. It's notated f/1.8 or f/5.6 as well. As you can see the size of the aperture is inverse to the value of f-stop, higher the f-stop smaller the aperture, smaller the f-stops bigger the aperture. So at f1.8 the light received by the medium will be more than f5.6; least light will be received at the smallest aperture say F22 of F45 or whatever your lens supports.

    Like shutter speed, aperture also controls one other aspect, apart  from the amount of light, it's called Depth of Field (DOF).  You maybe confused by amateur photographers who are fond of terms like DOF, Bokeh, Hyperfocal distance etc.  Just remember this rule of thumb & don't get lost in the jargon:  Bigger the aperture, smaller  (shallower DOF) the region of focus; smaller the aperture larger (deeper DOF) the region of focus.  You may, therefore, want to open up the aperture for a portrait shot wherein you want a  tack sharp face and blurred background & close down the aperture for a landscape shot wherein you want the entire landscape to be focused.  Also in macro shots, the amount of DOF is very critical since the available DOF is very less.  DOF is made use sometimes to give artistic effects to the photographs.

    Portraits would come out well with bigger apertures (smaller f-stops) for it makes the subject really sharp against a background of soft bokeh, Also night shots usually require bigger apertures which would allow lot of light to enter.
    Landscapes need smaller apertures (bigger f-stops) for most times it wouldn't have a specific focus point.  Smaller apertures help on a very bright day to cut-off excess light entering (of course this could be controlled by shutter speed too). 

    Aperture Sizes

    ISO is the measure of sensitivity of the media and is a camera dependent feature. ISO values are typically in the range of 100 to 3200 (on a pro camera it have extended range from  50-102400!!!)

    When the ISO is set to 100 the sensor is least sensitive, it can sense less light; when it's set to 1600 or 3200, the sensor can sense a lot more light.  Which means for a given condition if ISO 100 gives a standard exposure with F8.0 & 1/250th of a second, ISO 1600 may give a standard exposure at F8.0 & 1/1000th of a second.  As one can infer from the above, ISO comes very handy while shooting hand-held under low light conditions, it gives an advantage slightly faster shutter speeds which helps you in avoiding blur.

    An obvious question may arise to a novice, "Why  should I shoot at low ISO when higher ISO gives an advantage of faster shutter speed?"   Though ISO seems to be such a cool feature, it carries with it something very undesirable - NOISE.  Higher the ISO, higher the noise.

    Brighter the ambience smaller the ISO (unless you want grainy effect), darker the ambience higher the ISO.

    Noise comparison

    Focussing: Focal Length, Zoom/Prime, Focus Types:

    Focal Length:  is very much an attribute of lens.  Let me not become a physics lecturer here giving you the basics of optics using diagrams, instead let me try to explain it in layman terms.  Shorter the focal length wider the area you can cover, longer the focal length lesser the area you cover.  In other words, shorter the focal length smaller the objects appear and longer the focal length bigger the objects appear.   Focal length may vary from 5mm all the way upto 1200mm or more.  So as per the definition, lenses in the range 10-24mm would cover whole lot of area and hence will be used for landscape and architecture shots and are called wide-angle lenses; similarly lenses in the range 200-800mm could be used for shooting something far e.g. a dog at the end of the road or bird on the tree or cricket ball striking the bat or a cheetah pouncing on deer and are called telephoto lenses. Lenses in the range 24-135mm could be considered as mid-range lenses. 

    Focal length demonstration

    Zoom/Prime:  Most novices (the ones with no knowledge of SLR cameras) ask me a very typical question, "Saar what's the zoom of your camera?"  So if you're one of those who asked that question, I'll make sure you won't ask such a question next time if you read this section.

    Zoom is nothing but the ratio of minimum to maximum focal length.  E.g. Canon Powershot SD4000 comes with a 28-105mm lens, so zoom = 105/28 = 3.75x.  Nikon Coolpix P7000 has a 28-200mm, zoom = 200/28 = 7.14x.   SLR cameras won't have any zoom associated with them coz it's the lens  that you mount on the camera that determines the zoom.  So if you've loaded your camera with a 70-200/4L lens the zoom is about 3x, but it's not so significant.  SLR lens buyers don't have to bother  too much about zoom but sheer optical quality and the purpose of the lens, zoom is a factor that is more worried about while buying a point-&-shoot camera.

    Now a small question: what is the zoom if I plug a 100mm lens?

    Those kinda lens are called Prime lenses.  Prime lenses are fixed focal length lenses like 50mm/f1.8 or 100mm/f2.8 macro or 800mm super telephoto etc.  These lenses won't have any zoom ring to rotate for zooming-in or zooming-out, so if you really have to change zoom the only way out is either you or your subject has to move back/front.

    If this is the case then why do we need the prime lens at all?

    Prime lenses are very easy to construct and are optically much superior than the zoom lenses.  If you see Canon's high end lenses like 600 or 800mm L lenses, it becomes extremely difficult to construct zoom lenses at that range and they end up constructing optically very superior prime lenses which costs a fortune.  I have two prime lenses 50mm/f1.8 a dirt cheap lens which works wonders and a 100mm/f2.8 macro which gives tack sharp images, I just love shooting with these two lenses.

    Zoom demonstration

    Focus types:  You can either use automatic focussing or manual focussing, each of it has their own pros and cons which we discuss here.

    Automatic focussing is a hassle-free mechanism where-in you leave the focussing decision for the camera.  It could be in fully auto-focus mode where the camera even selects its own focus points when you half-press the shutter-release button.  Here both the auto-focussing mechanism of the camera and the lens motor plays important role, high-end cameras are equipped with better focussing mechanisms than the entry-level ones.  Auto focussing is especially useful in sports photography and wild-life photography where the subjects are moving at high speeds (though this requires predictive or artificial-intelligence focussing to be enabled).   The other form of auto focus mechanism is focus-point selection, the photographer can  choose one of the available focus points that's visible in the view-finder, this option gives better accuracy of the region of focus.

    The flip side of auto-focus is "hunting".  Sometimes when there are too many distracting elements or if the light is too low or while shooting macro, you might have observed that your lens makes lot of noise and fails to focus, this is called hunting and this happens when you let the camera to focus.  The camera gets confused due to too much or too less contrast differences as to what to focus.  Also the other problem of auto focus is the camera may not really focus the region which you intend to focus.

    Manual focussing mechanism is when you set the AF-MF switch on the lens to MF.  Once this setting is done, the camera's inbuilt auto-focus system is completely disabled and the photographer has to use the focus ring on the lens to achieve the desired focus.  This definitely gives greater control to the photographer and comes especially handy in the scenarios mentioned in the cons of auto-focussing.  I particularly use manual-focussing while I'm shooting macro.

    Cons of manual focussing is the speed.  Photographer has to see through the view finder, decide on the region of focus, turn the focus ring and click, by this time a cheetah would have completely devoured the deer and left or the best-goal would already be kicked.  Manual focussing is hard to use for elusive or high-speed photography like sports, wild-life, street etc.

    AF-MF selection switch on lens

    Metering:  This is often the most confused topic.  Depending on the camera it may support any of spot-metering, evaluative metering, partial metering, center-weighted average, 3D colour matrix, multi-zone metering etc.  I'm not gonna explain all of them, I'll explain spot metering which is the simplest of all.

    When you see the exposure meter of your camera either through the viewfinder or on LCD, you see the exposure indicator moves when you change any of the exposure parameters.  How would the camera know what exposure to set?  It would have some presets in the memory against which it compares the incoming light and sets the exposure.  Now, metering mode determines light from which part of the composed frame is used for comparing; our common sense says that each of the metering mode will result in different exposure values depending on the light emitted by the subject.

    Metering modes explained

    Coming to spot metering, imagine a scenario wherein you're clicking a full moon on clear cloudless night with, say, a 200mm lens.  Since the overall scene is predominantly dark except for the moon, if you use multi-zone metering and shoot the moon will get over-exposed.  Because the camera picks up light from the entire frame and the light entering is very less and it tries to set an exposure to compensate for the darkness which washes out the moon.  To overcome this problem, set your metering mode to "spot-metering", usually denoted by a frame with a dark spot in the center.  What this would do is, it measures the amount of light entering only through the central circle of the viewfinder.  So place the moon at the dead center of your composition, underexpose by a couple of steps and shoot, you see all the details of the moon.  That's because the camera would now consider the light coming only from moon and ignore the darker sources and meter it aptly.

    Canon Viewfinder

    Resolution - Mega pixel (MP), Size: 

    Time to get our fundas correct first.  Lets take an example of my camera, 20D.  It's an 8.2MP camera, what does it mean?

    1MP = 1 million pixels

    The biggest image size it produces is 3504 x 2336 pixels.
    So multiplying these two you get 3504 * 2336 = 8185344 pixels ≈ 8.2MP

    You might have heard of the term DPI in printing jargon, DPI stands for Dots Per Inch and 300DPI is the minimum required for photo printing on magazines/books.

    To get the dimension of the print size:

    3504/300 = 11.68 inches
    2336/300 = 7.78 inches

    So with my camera I can get the biggest print of 11 x 8 inches.

    If we want bigger prints and ready to lose out on quality (still decent enough to frame and hang) we just need to reduce DPI.  For example,
    3504/200 = 17.52 inches
    2336/200 = 11.68 inches

    With a little reduction in quality you can get a photo as big as 18x12 inches.  Mind you: further reduction in DPI will pixelate the image, stop at 200DPI.  300DPI is true photo-quality prints.

    Now to drool over a bit, lets take the case of Hasselblad H4D-60 medium format:

    8956 pixels x 6708 pixels = 60MP
    8956/300 = 29.8 inches
    6708/300 = 22.36 inches

    So you get a photo of size 30 x 24 inches for shelling out about 20 lakhs!!!

    Megapixel chart (Figures in box indicate DPI)

    White Balance, Colour temperature: 

    Have you ever come across a situation in which you've felt that your camera is not actually capturing the colours the way you're seeing, especially when you shoot under a florescent lamp or with a flash or on a overcast day?  White balance is creating problem here.  Lets try to see what's it and what's gone wrong!

    Let's start off by seeing what's colour temperature, wikipedia says "The color temperature of a light source is the temperature of an ideal black-body radiator that radiates light of comparable hue to that light source. The temperature is conventionally stated in units of absolute temperature, kelvin [K]. Color temperature is related to Planck's law and to Wien's displacement law."

    Kinda intimidating isn't it?  I know! That's why don't go by theoretical definitions of stuff.  Let me put the above statement in laymen terms - "Bluer your image cooler it is, browner your image warmer it is".  So if you shoot your photograph under florescent lamp it's gonna be cooler, if you shoot it during sunset it's gonna be warmer.  The camera usually gives multiple WB options viz. tungsten, fluorescent, cloudy, flash etc. but most times AWB (Automatic White Balance) setting works perfectly well, but at times the camera may fail to capture the right temperature.  The only way to fix this is by post-processing.

    My Tip: Shooting raw particularly helps in playing around with WB settings.

    Colour temperatures

    A bit about lens and filters:
    All of us agree that the lens play a major role in photography - it is the eye that actually sees the subject!

    Lenses could be classified by various parameters:
    Focussing types:  Auto focus & manual focus (already discussed)
    Aperture: Slow lens, fast lens (aperture bigger than f/2.8)
    Focal length: Ultra wide angle, wide angle, mid-range, telephoto, super-telephoto
    Motion compensation: IS, non-IS  (IS: Image stabilization or VR: Vibration Reduction, a technology in which the lens contains a motion sensor that compensates for slight camera shakes)
    Others: Macro (special lens used for extreme close up), tilt-shift (special lens used for architecture photographs), fish-eye (extreme wide angle lens resulting in hemispherical image)

    Depending on what you shoot, you choose your lenses, it's always better to have one mid-range (E.g.24-105mm) that comes very handy during travels.  Longer the focal length, bulkier the lens gets, complicated the construction becomes, higher the cost goes. Parameters to look for are optical quality, build quality, focussing speeds, low light performance and portability.  Also one has to really decide if he wants a fast lens or he can make do with a slow lens, the reason is, Canon 70-200/4L  costs about $400+ while 70-200/2.8L costs a whopping $1200+.

    Filters are of various types:
    • Neutral Density (ND) filters are the dark glasses which cuts the light entering the lens.  You may shoot back, "I can anyway control the light by 3 exposure parameters that you've already talked about, why do I need a ND filter?"  Think of a situation where you want to capture a beautiful waterfall with a nice milky fall effect on a bright day - with aperture closed down to F/45 and ISO at 50 it may still give you a shutter speed of 1/60 which is not enough to get the desired effect, you would need 1/5th of 1/2 a second of shutter speed and if you shoot with that setting it washes out the waterfall.  So under such situations one has to artificially cut down the light and ND filters come very handy.
    ND Filter

    • Graduated Neutral Density (GND) filters are partially darkened and are useful in sunset/sunrise shots wherein the sky needs to be underexposed and land needs to be overexposed. 
    GND filters

    • Color filters are mainly used in B&W photography to enhance the contrast.  For example, a blue filter makes the blue sky brighter, a red filter darkens the sky and brightens skin tones.
    Colour filters

      • IR filters are the special filters sensitive only to IR light.  IR photographs look very surreal and snowy.
      How an IR photograph looks

      • Polarizing filters are used in colour photography mainly for two reasons.  Primarily it cuts down harsh reflections and secondly it makes the color pleasantly warm and saturated.  It does exactly the same what a polarizing sun-glass does to your eyes.

      Reducing reflections


      • UV filters serves the purpose of reducing the haze and protecting the lens from harmful UV rays.

      My equipment:
      Canon EOS 20D
      Canon 17-40/4L for landscapes
      Canon 70-200/4L for street and not-so-far subjects
      Canon 100mm/f2.8 macro for macros and portraits
      Canon 50mm/f1.8 for portraits
      Canon Speedlite 430EX II flash

      I post-process all my RAWs (usually colour-&-contrast corrections, cropping, vignetting, noise reduction, sharpness) using Apple Aperture 3.1 on MacBookPro running Mac OS X 10.6

      This one's nothing but a collection of my bookmarks which I had collected over many years, some tutorials, some galleries, some forums etc.

      Mother of all photography websites with loads of resources -
      Reliable lens reviews:
      My inspiration, Henri Cartier-Bresson: 
      EOS Beginner's FAQ -
      Loads of f-number arithmetic stuff could be found here -
      Some good articles here -
      DOF calculator:
      Camera archive at pbase:
      George Steinmetz:
      Best of Photojournalism:
      Paul Liebhardt:
      Lovely landscapes by Lidka and Marcin:
      Miscellaneous photography resources:
      Ansel Adams:
      Parc Photography:
      Landscapes by Elizabeth Carmel:
      Vincent Laforet:
      Joel Sartore:
      Steve Winter:
      Steve McCurry:
      James Nachtwey:
      Bob Atkin's Canon resources:
      Kalyan Varma photography:

      Tuesday, November 16, 2010

      With eyes wide open

      Today is his second day and as though he heard my gripe in my previous blog that he didn't give me an opportunity to click with his eyes open, he did open and posed for the camera today.

      Monday, November 15, 2010

      Birth of the Prince

      On 15th November 2010, exactly at 0515hrs a prince is born at Panacea Hospital, Bangalore.  He weighed 3.5kg and came into this world in the most natural way without paining his mother too much.  Don't blame me for not taking any photos with his eyes open for he never gave me that opportunity today.

      Saturday, November 13, 2010

      Diwali 2010

      Last year's Diwali photographs could be found here.
      This was the first Diwali for me after wedding and traditionally I should have been in my in-laws place getting pampered, hogging sweets they prepare and firing crackers.  Since firing crackers is banned in Shanghai, I decided to spend my Diwali here at my place and my wife was pampered, fed with sweets, made to fire crackers and she felt very festive for the first time here.   She prepared lanterns and lit lamps and enjoyed her first Diwali in India (the previous was in China some five years ago, read about it here). I, as usual did some clicks and the results are below.  The most challenging part of shooting was the unpredictability of the explosions in the sky.   All photographs were shot hand-held, all explosives shots were shot with 70-200/4L on 20D, touched using Aperture 3.1.