BlogCatalog

Rain Rain Come Again, Little Johny Wants to Shoot

Rain—a word that reminds all photographers about dehumidifier chambers, dessiccants and that familiar creepy mark on their lenses. But for many Mumbai photographers like me, it is very refreshing thinking about the monsoons, notwithstanding the memories of that terrible flood in 2005. For most of them, it’s a long wait for his dear images.

The long wait for some clouds

A photographer at the busiest place in India, who likes to shoot nature, buildings and cloudscapes, is like a hornbill, waiting for the rain. No, not because it’s too hot over here. But the rain washes away all the dirt from his subjects—trees, buildings and the like—and helps the dust in the atmosphere to settle down, clearing the haze and smog. A bit of sunlight in the intermission can bring up the bright blue backdrop of the sky with white, cottonball-likeclouds floating here and there. Beautiful cloud patterns, brilliant glass windows reflecting those clouds, fresh green vegetation…

I wish there were some clouds on the glass

But till the first drop of rain comes in, most of Mumbai is covered with dust and other pollutants. The sky, most of the time, has an uninteresting hue of gray, which gets mirrorred on water bodies and glass windows too. Shooting building and trees are not options at all since all that we can spot easily are covered with dust.

Wish we had something like a ‘dust filter’ that could be screwed onto the lens like an UV filter.

Canon EOS 5D Mark II and Pentax K-m Reviewed

Last month I got the chance to review the 10-megapixel Pentax K-m (K 2000) DSLR and the 10-megapixel Ricoh R10 compact.

The two-lens kit of the Pentax K-m contained the standard DA L 18-55mm f/3.5-5.6 AL and the DA L 50-200mm f/4-5.6 ED lenses.  The camera features a built-in CCD-shift Shake Reduction feature, allowing backward compatibility with your old K-mount lenses, making them work like true VR lenses. It uses four AA-type batteries for power and an SD card for storage. The camera gives you the option of saving the RAW images as PEF as well as DNG, allowing compatibility across different platforms. 

The Ricoh R10 features a 28-200mm f/3.3-5.2 lens (35mm equivalent) and has an impressive macro mode. It also has a level indicator that warns you when the camera is not level with the ground.

Read the complete review in the February 2009 issue of Smart Photography (now on stands).

Other reviews in the issue: Canon EOS 5D Mark II, Panasonic Lumix LX-3, Canon PowerShot A590 IS.

Also in the issue: Smart Photography Awards 2009, PhotoFair 2009, Learnings—Focus Stacking, Perspective Control, Smart Sharpening, Professional Photo Retouching in Photoshop, Interview with Tarun Khiwal

f-numbers and Their Significance

All of us who are into advanced photography, would be familiar with the numbers associated with aperture of the lenses. These numbers, known as f-numbers, go on as: 1.4, 2, 2.8, 4, 5.6, 8, 11, 16, 22, 32 and so on. But ever wondered why these should be in the form of complicated fractions and not whole numbers? After all, the only significance we find in these numbers is the fact that the light becomes double when we decrease the f-number by two. So life would have been much simpler without all these fractions…right? But what is the significance of these fractions?

f-number is a measure of the ‘relative aperture’ of a lens. This is the ratio of the focal length of the lens to the diameter of lens opening (aperture).

i.e.,

f-number = focal length/iris diameter

In other words, it is the number of diameters of the lens opening present in the given focal length. Hence when the f-number is 2.8, the focal length of the lens is 2.8 times the diameter of the iris opening. This is why the number becomes smaller as the aperture grows larger. When we change the f-number to the one near it, we say that the light changes by an f-stop. The f-stops have been selected such that when we increase the aperture by one f-stop (or decrease the f-number by one unit), light intensity doubles. And since intensity of light is proportional to the square root of distance, each f-number is √2 times the one preceding it. So the numbers double for every two stops.

Hence, the f-numbers can be written as:

1, 1 x √2, 1 x √2 x √2, 1 x √2 x √2 x √2, 1 x √2 x √2 x √2 x √2, 1 x √2 x √2 x √2 x √2 x √2,…

i.e., 1, 1.4, 1.979, 2.8, 3.959, 5.6, 7.919,11.2,…

After correction to the nearest decimal point, this series becomes:

1, 1.4, 2, 2.8, 4, 5.6, 8, 11,…

Exposure

A camera is nothing but a light tight box with a medium to record images, and some mechanism to control the amount of light falling on the recording medium. The amount of light striking a particular point can be controlled by either limiting the size of the opening, or by limiting the time for which light is allowed to pass. The mechanism to reduce the opening is known as Aperture, while the one to limit the time for which the light is passed is known as shutter, which controls the Shutter Speed. Thus, the two parameters—aperture and shutter speed—control the exposure taking place on the light-sensitive medium

So for the exposure to be correct, the combination of aperture and shutter speed should be correct. If the image appears  darker than the scene (i.e. the light striking the medium is less than optimal), the image is said to be under exposed. On the contrary, if the image is lighter (i.e. the light striking the medium is more) than than required, the image is said to be over exposed.

White Balance

Perhaps all digital camera users are aware of this setting, but I can safely bet that not more that 20% of them know what this really means, and what it does to your images. Let me attempt to demystify this term. First of all, let me take you back to the most hated place you have ever been to, where someone used to preach all about the sunlight, dispersion, diffraction and stuff like that.

Normal daylight is made up of component colours like Violet, Indigo, Blue, Green, Yellow, Orange and Red. The light from different sources differs in the intensity of each colour. Since daylight is the most dominant in our lives, we consider it as ‘neutral’ light (because we are more used to seeing the world in this light than any other light). ‘Tungsten’ light sources are composed of more warm tones (towards red) of light than daylight, while fluorescent is more cooler (towards blue) than daylight. So if we take photographs under these light sources, we are likely to get different colour casts in the photographs and hence we need to ‘educate’ the camera what source of light we are using. What the camera does is that, if we set the white balance to Tungsten, it will add a blue cast to the image so that it cancels the warm cast. Similarly, if you shoot with Fluorescent white balance, the camera will introduce a warm tone so that it cancels out the cooler cast. In simple words, with white balance, we instruct the camera what compensation it needs to make in order to make a pure white paper appear pure white under a particular lighting condition.

Experimenting with different white balance settings can give interesting effects to otherwise ordinary-looking images. For example, in the images below, the first image was taken with Daylight white balance, while the second one was shot with Tungsten white balance.