The Art of Panning

Now that the basics have been dealt with, lets move on to other stuff. Here's one of my favorite techniques, called panning:This technique is used to show movement by keeping the moving object sharp while blurring the background by movement, not by DoF.

First, depending on the speed of your moving object select a slow shutter speed. First try something in range 1/10 to 1/30 s, and adjust according to the results. If its day time, to properly expose, you'll need a small aperture like f/8 or something, so you don't have to worry too much about focal plane shifting while your subject moves, because the DoF will be quite deep. Use continous AF if your camera supports it/manual focus to where your subject will be/ infinity focus if your subject is far enough)

I shot the above picture from my verandah(which happens to have black grills) with a shutter speed of 1/8 seconds on a 50mm lens (ISO 100, aperture was forced to be f/22 to correctly expose).

After setting up your camera, allow you body to face the direction where your subject will pass.

While keeping you feet stationary, twist your upper body towards the subject. Put your camera up to your eye. Keep your finger on the shutter release. Then track the subject as it passes through space, with a smooth horizontal twist, trying to keep its position fixed in the viewfinder. Somewhere in the middle of this twist, press the shutter release, but continue the twist motion. Allow a large enough follow-through, even after the shutter closes. This will ensure a smooth action.

The goal of panning is not to show a crisp object and a blurred background. Its idea is to depict speed, and all you need to do is have the subject a good deal sharper than the background- but not necessarily perfectly sharp, as a still object would appear.

Panning is not one of those techniques that just comes off easily. It does require a lot of practice to execute well. Hope you guys learnt something useful from this!

Until next time. Keep shooting! :)

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ISO Speed

ISO is the sensitivity of the sensor to light. If you double the ISO, u need half the amount of light to expose correctly. Higher ISO also implies more noise(those random color specks you sometimes see in a photo).

Upto a certain amount, noise can be dealt with using noise reduction software light neat image, noise ninja, etc. When noise is too much, using noise reduction software decreases d noise, but takes away a lot of detail too.

Higher ISOs also decrease the color quality and dynamic range to some extent. I dont know what more to say about ISO actually, I dont think you dont need to know anything more about it...

UPDATE: I just thought of an interesting analogy for ISO...

Assume:

Merc ~ ISO 200

Honda~ ISO 400

Fuel~ Light

Destination~ Exposure

Ok, here it goes: A Honda(ISO 400) will consume half as much fuel(light) as the Merc(ISO200) to reach the same Destination(Exposure). However, the Merc will give you a better ride(less noise/better picture quality)

ISO 200:

ISO 1600

these are 100% crops(click on each image to see it). Notice that the ISO 1600 shot has a lot more noise compared to the ISO 200 one(negligible noise). The ISO 1600 shot is still usable because these were taken using a DSLR... on point and shoot cameras noise becomes really nasty from ISO800 onwards.

Shutter Speed

Although we call it shutter speed, its actually the duration for which the shutter remains open to let in light.
Obviously, a shutter that remains open for 1/100th seconds lets in twice as much light as a shutter that remains open for 1/200 seconds.
Shutter speed allows us to control a vital aspect of photography-> Motion.
You can use a fast shutter speed to freeze a moment in time, or use a slow one to show motion blur.(movement)
The shutter speed you choose will depend on what you are trying to show, whether blur or stillness, and also on the speed of your object. Keep experimenting with it. Its one of those things one learns best with experience.

There is a rule which says the shutter speed should be faster than 1/(35mm eq. focal length of lens) for a handheld photo, to try and prevent blur due to hand movement. But some of us are steadier than others. Try and find how for how long u can keep the camera still on a given focal length so that >70% of snaps at that shutter speed are sharp.

(On my 50mm lens, which gives ~80mm(35mm equivalent) due to the 1.6X crop factor, I can manage quite well upto 1/30s. slower than that, I do get some blur)

a few more interesting things-> Slow Sync Flash: Using a slow shutter speed like 1/10 s to let in ambient light, but the flash also fires in the beginning or end, depending on whether you've set it to front curtain or rear curtain respectively.
Rear curtain is interesting as it allows motion to flow and freezes it at the last instant.
Heres an example of slow sync with rear curtain (A pic I took in spree '10) :

There is one more aspect of using flash and shutter speed. Many cams, especially DSLRs, theres a certain shutter speed, above which the flash wont fire. On my canon 400D its 1/200s. So be careful when using fill flash outdoors, the flash will not fire if u use a shutter speed of say 1/500s., unless you use an external flash and put it to 'high speed sync'.

The reason for this phenomenon is this(read if you are curious): The shutter has 2 curtains. For a shutter speed of say 1/10s, initially the first curtain opens exposing the top part of the sensor to light first. After it opens completely, the second curtain closes, blocking light from hitting the top of the sensor first and eventually covering it up completely. This lets every pixel on the sensor be exposed for the same duration of time... The same process happens upto about 1/200s. At one point int time, it became difficult for shutters to cross this 'speed barrier'. But then, camera manufacturers came up with this trick for speeds faster than 1/200s. As the first curtain reveals light, before it has completely opened, the second curtain starts closing. Its effectively like a moving slit that allows light to pass through to any given pixel only for that short duration of time. this slit moves from top to bottom.

Now consider using a flash in such circumstances. The duration of a strobe of the flash is very short (~1/10000s or less). If the flash were to fire, you'd get a brightly lit rectangle in the image with the rest of it only exposed to ambient light! To protect you from this, the camera will not allow you to choose a shutter speed >1/200~1/250(depending on your model) when the flash is on.

(High speed sync flashes actually reduce the power of the flash, but the flash lasts for a long duration of time-(via multiple short synced bursts) enough for the slit to scan over the whole sensor)

Aperture

Given a scene, there are 3 main settings you can change to control the exposure of an image: Aperture, Shutter and ISO... these 3 are generally referred to as the exposure triangle.

Before getting into the details, I would like to give a rough though not perfectly accurate analogy, just to get the feel of these 3.

Imagine you wish to fill a bucket( volume= x litres) with water, under a running tap. Your aperture control is the knob of your tap. Shutter speed(duration) is the amount of time you keep the tap open. ISO is k/x, where k is some constant. Close the tap partially(analogous to making the aperture smaller) and you have to increase the time for which the tap is kept open(shutter speed) in order to fill up the bucket.... Or you could instead use a bucket with less volume (increase the ISO).

Now coming to Aperture. It is basically the size(diameter) of the opening of the lens. The aperture size is controlled by aperture 'blades'.

On cameras, the aperture value is not stated as a diameter size in mm. Rather, it is stated as an F-number, like f/2.8 (P.S. F2.8 means the same as f/2.8, dont let notations confuse you!). The way F-number is calculated is

F-number=(Focal Length of lens)/(Diameter of Aperture)

for example, if I have a 50mm lens and the diameter of the aperture is 20mm.

50/20= 2.5

therefore the F-number is F2.5 or f/2.5

This means, the LARGER the aperture, the SMALLER the F-number.

Also note, as amount of light varies as the area of the opening, an increase in the diameter by square_root(2) times(~1.4 times) will double the area and hence double the amount of light entering.

f/1.4 lets in double the amount of light as f/2.0

similarly, f/4 lets in 1/4th the amount of light as f/2, not half!

The other important aspect associated with aperture is the Depth of Field-> the range of distance where objects are 'acceptably sharp' or perceived to be in-focus.

A large aperture(small F-number, like f/1.8) will have a very shallow depth of field compared to a small aperture (like f/8, f/16, etc )

The image examples illustrate the effect of aperture on DoF. Both images were shot with my EF 50mm f/1.8 lens(this says that the largest aperture possible on this lens is f/1.8) focussed on the grills. See the change in sharpness of the background!

So if you want to blur the background(especially useful for portraits), use a large aperture (small F number)!

Last, but not least, unless absolutely necessary, do not stop the aperture down below (i.e. don't make it smaller than) f/8 on a normal digicam, f/16 on an APS-C DSLR (entry level DSLR-> one that is not full frame). The reason is, although DoF increases, due to diffraction of light, your pictures will lose sharpness.(I could write a whole page on diffraction and the effect of the sensor size and pixel density, but it would bore almost everyone to death! :p )

Now turn your camera dial to Aperture Priority and experiment with different aperture values!

Camera Modes?

In this article, I will try to explain what the modes P,Av(A on Nikon),Tv(S on Nikon I think)& M basically do. I will NOT explain anything about scene modes(like portrait and fireworks!), because those are for people that take pictures. We on the other hand, would like to make pictures- pictures that look exactly the way we want them to.

The picture shows what a typical canon DSLR dial looks like.

First of, we start with P or Program mode. This mode is the simplest of the 'creative' modes. Unlike Full Auto, this allows you to change ISO value(sensors sensitivity to light), ev (exposure value compensation), white balance(WB). It also allows you to change between 'combinations' of shutter speed and aperture. You can use it for a while after 'graduating' from Auto :p

(I will explain each of Aperture, Shutter and ISO in a later article)

Next, we have Av- Aperture Value (people call it Aperture Priority). This lets you choose the aperture value. According to the available light and your camera's metering, the camera will calculate the appropriate shutter speed. ISO, WB and ev can also be changed. It is used when the main thing you want to control in the photograph is the depth of field- the range of distance in which everything is 'acceptably sharp'(basically, how much looks 'in-focus').

Tv- Time Value (also called Shutter Priority): This is the opposite of Aperture priority. You have to choose the shutter speed and according to the light & metering, the camera will decide the appropriate aperture. ISO, WB and ev are changeable. Use it when the more important aspect you want to control is motion & motion blur. Useful for panning sometimes.

M- Manual-> gives you control over ALL settings. Use when you have time to set up or when the lighting is not predictable. You need some extra practice with manual for it to start feeling natural. Preview the picture you've taken and adjust the exposure accordingly. The camera's light meter will only guide you with your exposure, it will not make any changes to your settings.

In manual, you also have an interesting Shutter Speed. A 'B' comes in the area where a time value usually appears. This is called 'Bulb mode'. In this mode, the shutter remains open as long as you hold the shutter release down(or the time between 2 clicks of a shutter release cable). Use on a tripod unless you're trying some creative effect.

My favorite mode is Aperture Priority. I like choosing the aperture for the situation(to control DoF) and setting the ISO according to the lighting. The metering is accurate >70% of the while, and if needed I just increase/decrease the ev which effectively changes the shutter speed. The only times I use Manual are when the metering is off by a large margin (> +/- 2 stops from what I want), or when the lighting is very constantly changing and driving my meter insane! :D (Reminds me of BITS Pilani Goa auditorium- they can sometimes be so unpredictable with the lights! )

Thats all for now. Try out these modes when you can. Happy Clix!

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What is Photography?

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Well, photography is the art of taking photographs! Ha!

So what exactly is a photograph? Is it just a picture of a scene?

Hmm... to many of us, a photograph is something more than just a visual depiction of a scene. Photography, in its most true form captures life- emotions. The photograph should be able to evoke some feeling from its viewer-like joy, sorry, loneliness, hope, etc. An image which cannot do this is merely a snapshot.

Every photograph tells a story and whatever is included in the frame is part of that story.

You, as the photographer, have complete control over these elements(by changing your position, focal length, DoF, etc). Hence, as a photographer, its your job to make sure everything in the frame contributes to the story. If an element doesn't contribute to your story, it surely takes something away from it, therefore such elements should be removed.

Its not wrong to say then, that photography is as much an art of exclusion as it is of inclusion.

It is an art of creating order from chaos!

Photography is also a science. Not knowing how light behaves, can destroy your photograph.

A photographer must know the effects of changing the shutter speed, aperture, ISO, focal lenght, position in space, etc to make the most of a photograph.

A blown out sky can ruin an awesome composition. Every setting you change WILL have some effect on the photograph, so choose wisely.

Digitalization of photography allows you to experiment without spending money when u screw up! Use this to your advantage! Experiment and learn...

All in all, great photography occurs when science and art blend together; the co-ordination of the left and right hemispheres of the brain, if you may ;)

Alll this may make photography sound complicated, but don't let that scare you. For what is life without a challenge, eh?

For those who just want the picture(that says, "I was here"), by all means, change your camera to its 'Auto' setting, point at your subject and snap away. 'Spray and Pray' as they call it.

But for those that want their photographs to say something more, something like "I was here, saw this and felt like this... do you FEEL it?", then change your camera to Av/Tv/M and start learning. Over time, your photographs will improve.

P.S. I'm no pro. I'm just an amateur, learning about photography just as you probably are. Am just trying to share what I know.