The most difficult scenes to capture with a digital camera is always night scenes with portraits. Because you can’t ask the people you shoot to freeze for 10 seconds for your camera on tripod. Image is captured by the image sensor of a camera or the film in older era, by emitting lights or reflecting lights onto the sensor (or film), As an analogue device, image sensor is made up by millions of pixels of protons to absorb these lights and generate digital signals data to the brain of a camera, or the image proccessor.
That’s why the ambient lighting is the most important factor in capturing a beautiful scenes. The more light received by the sensor, the brighter or more colourful is the image. Otherwise, the less light is received by the sensor, the darker would be the image. This is when the camera needs to crank up (artificially by electronically amplifying) the sensitivity of the image sensor (which is different in film where different chemical was applied to get higher sensitivity) to be able to read or differentiate the objects. This is called ISO setting of digital camera. ISO 100 is the original sensor sensitivity. whatever higher figure like 200, 400, 800, 1600 or 3200 are all reference number of the amount of sensor amplification. Since there are artificial, image noise will be created. Noise of ISO 800 is definitely more than ISO200, and so on…
Off course, ISO setting required is also depends on the permeability of lights allowed through the camera lense, the fundamental element of a camera. The permeability of lense is again depends on its opening diameter which is called as F-number or aperture value. The smaller F-number or larger diameter or aperture means more lights would be allowed to go through the lense. Then more lights would be drop onto the sensor. So theoretically, lense should have its maximum diameter opened for light. However, in actual fact, it is easier to say than do…
When the opening of a lense is larger, it is more difficult for a lense construction to control the light emittance so as to have all lights to be focused onto the sensor. There is a technological limiting factor of doing so. Which is why, as rules of thumb, DSLR lense with a larger maximum aperture is always more expensive because it is really not easy to construct a lense with a large aperture while still able to focus sharp on the sensor. I’m not touching the design of lense construction here though which I’m no expert either. What I’m trying to emphasize here is, in order to shoot nice night portrait, investing on a larger aperture lense is a must!
Off course, you can argue that the size of the image sensor is another factor. Yes, the bigger the sensor is, the larger would be the pixels and more lights would be easily absorbed. This is also why a DSLR caould always shoot better night scenes than a compact camera because their sensor size is in a ratio of 1:4! Again, full frame sized sensor employed in those high end pro DSLR like Canon 5D or Nikon D3 is even better than cropped size sensor in Canon 500D or Nikon D90. Bigger sensor can handle high ISO better. But who normally can afford those cameras? They are just too expensive, bulky and heavy to carry along on budget travel that I’m keen on.
So, unless you could afford RM12k on full frame camera like Canon 5D or Nikon D700 for your travel (I would not do so…), investing on a large aperture lense for DSLR is a better bet for shooting great night scene portrait. The answer to it is the budget Nikkor 35mm f/1.8G AF-S DX Lens for Nikon Digital SLR Cameras.
Its F1.8 maximum aperture is 5-stops faster than the standard zoom lense of F5.6 which means your camera shutter speed can shut 5 times faster but still allowing the same amount of light gone through. That is how a night scene portrait can be captured perfectly.
UPDATED Here are some sample image that I captured using the superb Nikkor 35mm f1.8 fast lense on my Nikon D60 hand held to show you its capability of capturing low light images and its sharpness…
Indoor portrait shot with nature indoor daylight. Fast action of children needs fast lense like the f1.8 35mm Nikkor to capture!
Now I can have more photo collection of my children with natural ambient lighting. I just don’t fancy about flash lighting.
From those photos above that I took using only the Nikkor 35mm f1.8 fixed lense which includes night scenes, portraits and close up’s, I would say any traveler carrying a Nikon DSLR camera should have this lense fixed on, all the time, everywhere. - Travel Feeder.