Cooking and Photography

What does cooking have to do with Photography? At first thought you'd think there is not much. How about explaining the most important concept of photography using an analogy with cooking!

In any hot dish, you put the pan on the stove or in the oven, set the temperatue and heat it for some period. At the end of it, you may get the food that is cooked right and ready to eat. Or ... if you are not so good in your judgement or not that experienced, you will end up with food that is half cooked and raw or overcooked and burned.

The most important concept in photography is getting the right exposure in your picture. Exposure is basically the amount of light that you are allowing to reach your film. Getting the exposure right is very much like cooking. You allow too much of light and most of the picture will be overexposed just like food will be burned with too much of heat. On the other hand if you don't allow enough light, your picture will be underexposed just like not applying enough heat to your dish will leave it half cooked.

Now I am not a cook, but I can tell you there are so many ways to burn your food :-)

• Set the temperature to higher then necessary
  
• Leave the pan on the stove for long time
  
• It also depends on what is that you are cooking, rice will burn faster then a lot of other foods
  

Any of these setting would result in more total heat applied to the food then necessary.

In Photography, there are analogous settings that if not set right, would result in an over exposed image.

1. Aperture : The size of the hole that opens up in your camera's main lens, that will allow the light to be exposed on the film. Just like the temperature knob on the stove would allow more or less heat, the aperture setting would let more or less light come in. If you leave it fully open you may over expose your film.
   
2. Shutter Speed : The amount of time you leave the shutter open to let the light be exposed on your film. If you leave the shutter open for time longer then necessary, it will overexpose your film, just like leaving the food on stove for long will burn it.
   
3. Film Speed : The sensitivity of the film that you are using. More sensitive film capture more light in less time compared to a less sensitive film. This is similar to using a very thin Pan that passes most of the heat to the food. It may burn your food if you are not careful.
   

The same things are applicable in a digital camera, except that the light will be exposed on a CCD (an electronic component that mimics the film).

Check this picture, a birthday cake, overexposed.



Now oevrexposure in the above picture may not look that obvious to newbies. But when you see the same picture in negative, you will see a burned cake ;-) !



If I can use "burned" to mean "overexposed", in the above picture, you can see that major part of top of the cake looks completely burned, you can not see any details of the surface. The sides of the cake although do show detailed texture as it is properly exposed.

[ When u look at the image in negative, it becomes so intuitive to think of overexposing an image as burning it, isn't it ? :-) ]

So start thining like a cook. Be careful not to burn your pictures! And with a good Digital Camera, you have plenty of help at hand. Let's see what I mean by that.

Cooking with a "Smart Stove"
That's right, a digital camera is like a "Smart Stove"! Imagine a stove that would not let you burn your food! Once you place your pn on the stove, it somehow figures out how much of total heat will be needed to cook it. Then it let's you select one of the two items, temperature or time.

• You want your food to be ready in 5 minutes, and stove will automatically set the temperature for you.
• You just turn the knob to some temperature and the stove will automatically turn off once the food is ready.

In either case, you decide one value and the stove decides the other. Now instead of rice if you put spaghetty, it may decide for a different total heat and accordingly decide different time or temperature for you. But basic idea remains the same.
So how does digital camera help in "cooking pictures without burning" ? Here is how ...

Metering

Metering is the technique used by your camera to come up with the right amount of light to allow. The camera analyzes the content of the scene (various colors and their brightness etc) and then comes up with an Exposure Value - a value that indicates total amount of light that is required for proper exposure.

Aperture Priority Mode

In this mode you select the aperture and the camera selects the shutter speed such that total light allowed is equal to the exposure value. Typically this mode is indicated in your camera's settings with a "Av" for "Aperture Value".

Shutter Priority Mode

In this mode you select the shutter speed and the camera selects the aperture such that total light allowed is equal to the exposure value. Typically this mode is indicated in your camera's settings with a "Tv" for "Time Value".

Below is a picture of the Canon G5's Control dial, showing "Av" and "Tv" modes.



Hmm... I'm wondering if there were really a product like "Smart Stove!", it'd definately save a lot of meals from buring.