Thursday, December 31, 2009

Transition from Point and Shoot to DSLR

Point and Shoot world talk about the optical zoom whether it is 10X Optical zoom, 12X optical zoom or so forth but in SLR world we talk about focal length range of 18 mm - 35 mm or 70mm - 300mm and so forth. Lets see the correlation between optical zoom and these focal length ranges.

Optical zoom is calculated as a ratio of maximum focal length to minimum focal length. Which means if a lens has a range of 18mm - 55 mm then its zoom factor is 55/18 = 3X Optical zoom and similarly for 70mm - 200mm lens zoom factor is 200/70 = 3X (approx). Thus we see that optical zoom in both the case is approximately the same but shots captured from them will be different, explained later below.

In the specifications of Point and Shoot cameras it will be mentioned : Optical zoom is 12x and focal length is of range 36mm equivalent - 432 mm equivalent. This does not means that lens used in point and shoot has a focal range of 36mm to 432 mm but actually might be 6mm to 72 mm. So why do they mention 36mm equivalent - 432 mm equivalent lens. This means picture taken from these lenses will feel the same as taken from 36mm lens - 432 mm in 35mm cameras.

Because many people are familiar with focal lengths of lenses for 35mm cameras, the digital camera manufacturers choose to describe the focal length of their cameras by reference to the focal length that would produce a similar field of view on a 35mm camera.

By describing the lenses this way, the digital camera companies appeal to users' familiarity with 35mm camera equipment.

Lets see in little detail:

Change of field happens because the sensor size is different in different cameras. (smaller the sensor size cheaper the camera, more noise at low light).

While normal film cameras take 35mm film (it is a standard for the industry) there is much variety between manufacturers on image sensor sizes. The main reference point that people therefore use is the 35mm one which is considered ‘full frame’ size.

Details on this can be found here

The CCD arrays on digital cameras are typically much smaller than the imaging area of 35mm film. This means that the focal length that produces a "normal" field of view is much smaller in digital cameras.

Let me show this by an example. Here I am using two cameras to show the difference Sony Cybershot DSC H2 and Canon EOS 350D.

Specifications about sensors size and lenses are below:

Sony DSC H2
Sensor size 5.75 mm X 4.31 mm.
Lens Focal Range = 6.0 mm - 72.0 mm
Lens Focal Range (35 mm equivalent) = 36.0 mm - 432 mm

Canon EOS 350D
Sensor size 22.2 mm X 14.8 mm
Lens Focal Range = 18.0 mm - 55.0 mm ; 70.0 mm - 300.0 mm
Lens Focal Range (35 mm equivalent) = 28.8 mm - 88.0 mm ; 112.0 mm - 480.0 mm

Top picture is from Sony at focal length ~ 70 mm and bottom one from Canon at focal length ~ 70mm. The picture shows the difference in angle of view due to different sensor size shot at 70mm focal length.

Now lets see how equivalent Focal helps


Top picture is from Sony at focal length of 70 mm which is equivalent to 432 mm in 35mm camera. Next picture shot from Canon at focal length 270mm which is equivalent to 432 mm in 35mm camera. These two pictures look similar even though at different focal length and gives an impression of picture taken from 35mm camera at 430mm focal length..

Because of the smaller format of DSLRs, telephoto lenses have a narrower angle of view than the same lens on a 35mm camera – this is the so called ‘crop’. Angle of View is simply that viewing angle which fills the frame (of any format). This determined by the film format in relation to the focal length of the lens – not the focal length on its own.

‘Crop’ is a fairly good term – the imaging area is physically smaller. Less of the image circle projected by the lens is used, therefore it is a crop. The image remains the same size at the film plane for a given lens and subject distance – it is in no way magnified. It does, however, take up a larger proportion of the (smaller) frame and so it is easy to see why some people call it a magnifying effect. This is also why a tele lens appears so much more powerful – the field or angle of view has been reduced. This is great for nature and sports photographers as the net result is more real pull than before with no trade off of maximum F Stop loss.

As an example: on a 35mm camera a macro lens focuses a 24mm long insect onto the film at same size – this is known as 1:1 ratio, or Life Size. 2.4cm on the film is about 2/3 of the frame in length so it will print to 2/3 of whatever (full frame) print size is made. On a DSLR with the same lens and at the same subject distance, the image at the film plane is still 2.4cm long at 1:1 or Life Size. However, 2.4 cm is about full frame in size and the subject will now occupy all the frame. For a given print size the subject will appear bigger in the frame. Thus it appears magnified compared to a 35mm camera.

Monday, November 30, 2009

Counting a Dozen

My 3 year daughter was learning how to count which rendered an idea for this photo project - Counting a Dozen.
Each picture here corresponds to a number 1 - 12. Simmilar concept was compiled in DPS, one pic posted by a member every day for 12 consecutive days starting with number 1 and going all the way to number 12.
These pictures of mine are from the same collections of DPS

Blue Angels @ Houston

1 boot rising.

Blue Angels @ Houston

2 Hornets roaring.

3 Arches of Water Wall

3 Arches of waterwall inviting.

4th Traveler

4th traveller is following.

5 lil fingers

5 little fingers.

6 Colors

6 different colors (moods)


7 hearts falling.

8 windows

8 windows gaping.

9 Arches

9 arched doors inviting.

10 Lanes Freeway @ Los Angeles

10 lanes are guiding.

11 Birds

11 birds resting.

Tennis Ball Cans

12 cans of balls waiting to be opened...

Monday, November 9, 2009


Abstract_06Abstract photography is a field that leaves many puzzled as to what exactly it includes. The definition varies so much by photographer and gallery, it seems like there is no common ground whatsoever. Probably the most common reaction is, What is this supposed to mean? most abstract photographs aren't supposed to carry any particular meaning. Many intend to create a certain mood. For instance, cool colors, smooth lines and a soft focus may be intended to create a calming effect on the viewer.
Abstract photography is a process of using colours and patterns combined to create an image, with no true meaning or no clear subject involved. Abstract photography is not necessarily going to mean the same thing to everyone. and helps us concentrate on texture and colour rather than the whole subject.
The most common reaction to abstract photographer is probably an incredulous, curious, What is that? Many abstract photos have no clear or discernible subject, while others try and make the subject appear like an entirely unlike object.
Most abstract photographers focus on the everyday objects around them, familiar things that they show us through their third eye to be less familiar than we like to think.
Special attention to color is paid by abstract photographers. The use of color filters is a very common technique.
Another factor that many abstract photos have in common is close attention to texture. Repeating patterns are a favorite of many abstract photographers.
Abstract photography, because of the sheer amount of imagination and creativity involved in the process, also serves as an excellent exercise for photographers of other fields to help improve their craft in general, building skills in attention to detail, color and texture, and stretch the boundaries of their own personal style with experimentation. It's a wonderful type of photography to explore—try it for yourself.
My Shadow

Mark Raymond has a great collections on Abstract Photography.
Mark Raymond Mason
Collections of Abstract photographs

Thursday, November 5, 2009

Shooting Airshow with Point and Shoot Camera

Taking interesting pictures at an airshow does not always require expensive SLRs. Last weekend I attended my first airshow ever. 25th Annual Wings Over Houston Airshow at Ellington Airport on Saturday, October 31 and Sunday, November 1 2009. I'd share with you what I learned so far.
All photos were taken with a Sony Cybershot DSC-H2, and I'm describing my experiences specific to this model.
I found these features useful:
Manual focus: Most things happen pretty far from you, so you can safely set focus to infinity and just shoot away without the delay needed by autofocus.
Custom settings memory: Some cameras will allow you to remember your favorite settings. Before the show, I programmed the camera to: zoom at maximum, manual focus set at infinity (see above), continuous drive mode and Aperture was set up to 1/1000 sec.

And thats it after this it was just click click click ...

On the picture on right I tried to get US flag to add some flavor to the pic.

Bright and clear sky added more savor but be prepared for the hot weather. Wear a hat and apply sunblocker on exposed skin. Also, be sure to drink a lot of water to prevent dehydration

I used wide angle option for the photo above; the plane wasn't important, the smoke trail and vastness of the sky were.

And the audience's reaction was as interesting as the show in the sky.

To know more about this airshow and about Blue Angels you can visit these sites

Friday, October 30, 2009

Clicking Fireworks

Clicking Fireworks 01Whether it is Deepawali (Festival of lights) or Fourth of July it means Fun, Food and Fireworks. However fireworks photography is not as hard as you have been led to believe. I usually shoot fireworks with camera on tripod because to capture this magnificent light work we need a slow enough shutter speed to capture the falling light trails. Few things which needs to be kept in mind while shooting Fireworks

  • Framing: It is hard to guess the exact location where fireworks are going to explode so it is better to take wider shot and then crop the pics.
  • Focus: Again for the same reason it is hard to focus so turn off camera's auto focus mode. Either prefocus or set to landscape mode for infinite focus. 
Clicking Fireworks 02
  • Support and Eliminating Shake: Tripods or other sturdy support are a must for fireworks photography. Even the best image stabilization technology is unlikely to be able to give you a rock solid image.
  • Zoom lens: Use a zoom lens (ideally 200mm or more) so you can get in tight and capture just fireworks themselves.
Clicking Fireworks 03

  •  Aperture and Shutter speed settings: Usually it is recommended to shoot in two settings Shutter Speed set to 4 seconds and Aperture to f/11. Fire a test shot and fine tune these two settings to get the desired pics.
Clicking Fireworks 06

  • If you want fireworks and the background (like temple in pic), then use a wider lens.
  • Blending two image: Two seperate photos one of temple (wider lens) and other of fireworks (zoom lens) and then combine them together using Photoshop.

    Clicking Fireworks 05
More about  Fireworks Photography

Sunday, May 3, 2009

Picture Composition - Shooting Flowers

If you were to walk by some wildflowers in a field, you'd be looking down at these flowers growing out of the ground. That's why, if you shoot flowers from standing position, looking down at them like we always do, your flower shots will look very average. If you want to create flower shot with some serious visual interest, you have to shoot them from an angle we don't see every day. Getting down and shooting them from their level.

Do we need Macro Lens?

You don't have to have macro (close-up) lens to take great flower shots - zoom lens work just great for shooting flowers for two reasons:
  1. you can often zoom in tight enough to have the flower nearly fill the frame, and
  2. it's easy to put the backgrund out of focus with a zoom lens.
Start by shooting in aperture priority mode (set your mode dial to A), then use the smallest aperture number your lens will allow. Then try to isolate one flower. When you do this, it puts the background out of focus, which keeps the background from distracting the eye and makes a stronger visual composition.

When is the ideal time to shoot flowers:

There are three ideal times to shoot flowers:

  1. On cloudy, overcast days: The shadows are soft, and the rich colors of the flowers aren't washed out by the harsh direct rays of the sun.
  2. Just after the rain. This is a magical time to shoot flowers. Shoot while the sky is still overcast and the raindrops are still on petals.
  3. If you shoot on sunny days, try to shoot in the morning or evening. To make the most of this light, shoot with a long zoom and position yourself so the flowers are backlit, and all you'll get some spectaular back lighting.

Fake the rain

Instead of waiting for a rainy day to shoot, take a little spray bottle with you, fill it with water, and spray the flowers with water yourself.

Monday, April 13, 2009

Take the help of Histogram

Working digitally has a number of benefits, one of the most important being that the colour, brightness and tonal values of the individual pixels that make up the image are recorded as soon as the image is taken.
These values can be reviewed in two ways on the camera's LCD screen - firstly, as the image itself and secondly as a graphic tonal represenattion which is known as a histogram.Being able to interpret histogram will help you to assess whether or not your image has the acceptable tonal value that make for a well exposed shot.

A histogram can normally be called up on the LCD screen on the back of your camera when shooting or playing back images. It is the form of graph where the x-axis (horizontal) represents the entire digital tonal range from black to white (0 - 255), while the y - axis (vertical) represents the number of pixels with a specific tonal value. The right side represents the maximum white values your camera can capture. On either end of the histogram the light values contain no detail. They are either completely black, or completely white. The top of the histogram (top of mountain peak) represents the number of different colors, a value you cannot control, so it is for your information only. We are mostly concerned with the left and right side values of the histogram, since we do have much control over those. (Dark vs. Light). An ideally exposed image would generate a symmetrical,humped shape histogram that smoothes gently out to the black and white points at either end of the histogram.

Below are some of the examples which will help you to understand Histogram.

As it is obvious this picture is underexposed and you can see in the histogram on the right corner of the picture. The pixels are bunched up on the left side of the histogram and there are very few pixels on the right side. This picture can be corrected by increasing exposure. This is discussed in previous blogs.

Same picture was taken with increased exposure and you can see in the histogram that pixels are spread more as compared to previous one and picture contains more detail.

This picture is overexposed. There are very few pixels in the dark areas (left side) and the pixels on the white side (right side) are climbing up the right hand border. This picture can be corrected by decreasing exposure as discussed in previous blogs.

These pictures are correctly exposed as all the pixels falls within the histogram range.

Next I will be dicussing about Composition