Archive for October, 2006

One light on..

Candle Ligth

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Petunias

Petunias

Petunias

Camera: Canon EOS 300X;

Lens: Sigma 70-300 APO DG (Macro)

Film: Fuji Velvia 100F (Slide)

Aperture: 5.6 (Macro mode)

Green

Rain brings out the best colors of nature. Green is one of them

Purple Delight

Camera: Panasonic LUMIX DMC FX-09, 6.0MP

Digital Crop Factor

On Digital SLR’s, when mounted with a lens of given focal length, you would have noticed a considerable change in the Field Of View, when compared to a film camera. This is nothing but the “Crop Factor”.
Let’s consider the prime 50mm lens:

When mounted on a 35mm film camera the focal length of the lens remains the same i.e. 50mm, as the lenses are designed for 35mm films/equivalent sensors.

When mounted on any Digital SLR the focal length remains the same but due to the crop factor the field of view drops considerably, as the sensor sizes of most of the mid-level D-SLR’s are smaller than 35mm.

For Canon EOS 350D the sensor size is 22.2 x 14.8 mm

For Nikon D70S the sensor size is 23.7 x 15.6 mm

So a wide angle lens loses it’s field of view when mounted on a D-SLR (of sensor size less than 35mm)

For instance when a 50mm lens is mounted on a CANON EOS 350D D-SLR, whose sensor size is 22.2 x 14.8mm, the crop factor calculates to
crop factor = 35/(sensor size)

i.e. crop = 35/22.2 = 1.6
so now the field of view, for a 50mm lens, on a D-SLR translates to:

field of view = focal length of the lens X crop factor

i.e. field of view f = 50 x 1.6 = 80mm (i.e field of view is equivalent to a 80mm lens)

wow!! it’s almost become a tele photo lens. Note that the focal length remains the same but the field of view of this lens now becomes the equivalent field of view of a 80mm lens.

If you are a D-SLR (serious amateur level) user and if you are going to buy a lens then don’t forget the crop factor otherwise you end up picking up a 16-35 L series lens for 1,500 USD and when you mount it on your D-SLR you’ll have a field of view equivalent of a 25-56mm lens. So plan your buy keeping the full frame sensor in your mind.

Invest in expensive lenses only if you are going to switch to a full frame sensor in the future.

For Nikon and Fuji D-SLR users the crop factor is approx: 1.5

For Canon D-SLR users the crop factor is approx: 1.6

Pottery

Pot Making

  • ISO: 100
  • Shutter Speed: 1/25
  • Aperture: 7.1
  • Focal length: 50mm
  • Photographer: Praveen Chamarthi

Crack of dawn

This picture has been featured on the flickr’s interestingness page a long time ago. I thought I would share with you all.

Crack of dawn

I experienced this beautiful formation during my trip to Singapore.

Anatomical 18% gray card

Any SLR user (advanced) who shoots in “M” mode must have surely come across the term “18% gray”. So what exactly is this 18% gray and how does it affect exposure?

Mostly all cameras have an in-built light meter, which are calibrated for 18% gray i.e. the reference point for a camera’s light-meter to determine exposure are the surfaces that reflect 18% of the light that if falling on them. It is similar to a thermometer: At room temperature the thermometer stay at 94-97 deg i.e. the mercury in the thermometer remains stable during these temperatures. As the temperatures rise above this point the mercury starts reacting and shoots up the meter depending on the temperature it has been subjected to. So a reference point for a thermometer are the points at which it stays stable. Depending on this you can say if a person has a fever or if there is a drop in temperature. Similarly a camera”s light-meter is calibrated for, surfaces that reflect 18% light, or in other words, surfaces with 18% reflectance. So the mid-tones in your frame are rendered as surfaces that reflect 18% gray and deflection from this point results in an over or an under-exposed picture.

For instance if you compose a picture with your SLR camera in such a way that the frame is filled with any black material, the famous example is when you shoot a black cat. Place a black cat on a leather couch which is also black in color and then compose and shoot the picture with the whole frame filled with the black cat and the background, the black couch.

The results will be surprising you will see that the camera will fail to understand the shades of black and your picture will have a noticeable layer of gray on it. This is because of the camera calibration to 18%gray. Since the light-meter cannot find any mid-tones it renders the whole picture as gray. Similarly you can try this with your frame filled with only whites and you’ll see that the results are more or less the same.

So, how do we expose correctly for black cats ūüôā or rather when your frame is filled with same colors? The answer is very simple: “Use an 18% gray card/surface to determine the exposure”.

How do I take the reading for a good exposure? You can place the 18% gray card next to the subject of interest. Zoom in with your lens (or go closer) and now focus the gray card, adjust your shutter speed such that the light meter indicates perfect exposure. Now remove the gray card, zoom out and recompose your frame with your cat or whatever it is, DO NOT CHANGE YOUR EXPOSURE SETTINGS (let the reading be the one that you took off from the gray card) and then shoot et voila you now have a better and most realistic colors and shades of the picture as opposed to the one that the stupid light-meter has decided for you.

So now where do I get a gray card?

You can pick them at any of your local store for a few dollars.

What If I don’t have one or If you forgot one at home?

Most of the camera bag manufacturers (LowePro) provide the adjustable partition strips inside the bags with gray color. you can just strip on these and use it as your gray card. Alternatively an average human palm is supposed to reflect 18% gray so you are never out of options.

Tricky situations can be encountered when you are shooting a landscape with hills, clouds, flowing water, rocks and the green valley. Obviously, one cannot walk up to the hill place your gray card, come back place it on the water and then on the greens, take readings and shoot. The solution for this is quite simple and also complex

keep reading this blog for more on exposure techniques.

Good day people!

Avoiding Camera Shake

If you are an ardent shooter using a SLR (Single Lens Reflex) camera then am sure you would have experienced some shots with camera shake, even though it’s not dark. You would experience this quite often if you shooting in “M” (manual) mode.

Well there is a reason behind this and this is often referred to as the “Camera Shake rule

The safest shutter speed you can shoot without a camera shake is when you have shutter speeds greater than one over the focal length i.e. 1/f, where f is the focal length in mm, of the lens in use.

e.g. If you are engaging a prime lens like 50mm then for shake free shots make sure you shoot with shutter speeds greater than 1/60 seconds.

As the shutter speeds get slower the probability of loosing sharpness increases greatly.

Not enough light? use a tripod (with a shutter release), engage the flash depending on the distance between the camera (you) and the subject or brace the camera against any solid object. If you are not carrying a tripod then try to place your camera on solid base like a railing or any slab of stone near you alternatively you can try leaning on to a wall, take a deep breath and release the shutter without shaking the camera.

IF you have stable hands and follow the “photographer’s stance” with discipline then you can manage some sharp shots even at slower shutter speeds.

Hope this helps.

Good day and happy clicking

Thai food

22nd Sep 2006

There isn’t much I’ve done since morning. I had an early breakfast and sat at the Internet cafe for more than an hour to update my friends and to see if my job is still there :).

I slowly checked out of my hotel (check out time is 12:noon) I walked down to the quiet and airy Baan Sabai restaurant and decided to feast on some real Thai food

Tom yam soup with river prawns

Tom yam soup with river prawns

Ham and bacon salad

Ham n Bacon salad

Phad Thai fried noodles with bean sprouts

Phad thai fried noodles

stir fried chicken with Sweet and sour sauce
Stir Fried Chicken in Sweet and Sour Sauce

Fried noodles with mince beef

Fried noodles with mince beef

Silom Village and Patpong Street

21 Sep 2006

There are numerous places to shop around in Bangkok. For the more upbeat type of stores you can visit the Siam Paragaon and for more budget oriented shopping it worth a visit to the MBK shopping center at Siam center. You can reach MBK by taking the nearest sky train to siam (pronounced as sayyam) station. From Th. Khao San take the ferry service a.k.a Chao praya river express from Th. Phra Athit to Takshin ticket: 13baht, and then take the sky train to Siam skytrain ticket: 20baht. Siam is an interchange station commuters interchange here for travelling north of Bangkok toward Mo Chit (Northern bus terminal, buses to Aranyaprathet: Closest town to Cambodian border, depart from here but beware Mo chit skytrain station and the bus terminal are NOT close by so if you intend to go to the bus terminal I suggest you hail a cab or a tuk-tuk and ask for Mo Chit mai). Mo chit is also close the Chatuchak weekend market worth a visit. Even though this is a weekend market one can still find shops during the weekdays. The market opens at 9:00am and closes by 6:00pm.

For all you techies: Even though I haven’t been there personally I’ve heard that the best bargains for all kinds of electronic goods can be found at Panthip Plaza which is also very close to Siam square.

If you are an evening shopper, like me, then head towards Silom village and then to Patpong street. Take ferry service from Th. Phra Athit to Takshin ticket: 13baht, and then take the sky train to Surasak skytrain ticket: 10baht Silom village is walking distance from here. Cheap clothes, bags, wearables, shoes, tatoo’s and other accessories and available in abundance here.

Patpong street is for the hedonists. Dingy bars, sex shows, go-go bars, pimps (both men and women), massage parlours and anything sex sells here. As I walked down the street Murray head played in my head. Honestly, I thought whoever wrote this song must have landed directly from Don Muang (Bangkok International Airport) to Patpong street and he judged Bangkok. I walked passed all of the go-go bars dodging all the pimps out of Patpong and headed towards Sala Daeng, the closest sky train station after you exit out of Patpong street. Another mark that you are in Patpong is the sky train line which runs above the whole evening market.

The clock now struck 7:30pm I climbed the not so steep stairway (as compared to the steps at Angkor) and walked to buy my ticket back to Takshin where I would catch the ferry service back to Th. Phra Athit. But to my disappointment that day Wednesday the ferry service closes at 7:00pm, strange! I saw them operate yesterday at 8:00pm huh! well I should have read those days and timings a little more carefully. Anyways I hailed a cab and it rushed through the already fading traffic and dropped me off at Th. Phra Athit for 63 baht.

I walked down Phra Athit to find the night dwellers already on their duty and the street smelled of food. I stopped by a friendly noodle maker and bought myself a “mee foon” (rice noodles) and a spring roll for 35baht and on my way I picked “Singha beer” which has soon become my favorite.

Singha Beer