IS the above picture grainy (in film's term), or in digital photography's term, has a lot of noise? Yes, definitely. But I still like it. Because it captured an interesting moment which otherwise would have been lost; and in that sense, served its purpose. 

A higher ISO means that the film or digital sensor is more sensitive to light, and is frequently used in low light conditions. The disadvantage of a high ISO is typically high grain/increasing noise, lost details in shadows, and less vivid colors. Luckily, digital age has been able to push ISO a lot higher with reasonable amount of grain, from ISO 800 in film age to ISO 6400, or even ISO 12800. 

Do we always need to use a high ISO? No. When taking a picture, one should always starts from the lowest possible ISO as long as a correct exposure can be achieved. However, many times even the the combination of the biggest aperture and slowest shutter speed allowed for the situation still do not allow for enough light to hit the sensor and to achieve a correct exposure. Now we will have to adjust to a higher ISO. But don't start worrying yet. As mentioned, the amount of noise accommodated with a higher ISO has been greatly improved in digital age. For example, in Canon 5D Mark ii, noise and lost of details only start to show beyond ISO 800-1000. 

How much noise is too much noise? This is up to personal taste. Some may find even a low amount of noise distracting, while others may use high noise as an effective tool to communicate mood and atmosphere. I would suggest to do some experiments, and to find out what level of noise you are comfortable with, so that you can try to stay below that ISO number when you can.

Of course, there will be situations where there is just not enough light. In this situation, will you sacrifice the shot entirely (e.g. low ISO and low shutter speed, resulting in a motion blur), or sacrifice some clarity of the image by using the highest ISO that your camera allows? I would go for the highest ISO possible. For example, this shot is taken at ISO 6400, the highest ISO that my camera allows. Yes, there is grain and stuff, but hey, this way I still preserved the curious moment when the penguin and the boy were gazing at each other, wondering what each other's world is like.

It has been a brutal winter. We moved from my beloved NYC to Chicago right after thanksgiving, so to 'enjoy' the best of winter. Saying goodbye to good friends and favorite city; moving and adjusting to the new environment, and the endless cold cold winter has caused a plunge in my spirits. 
My footage piled up. My joy of taking good photos seems to decrease, and I doubted myself. 
The other day I got in touch with an old friend. "Take a look at my website." I said out of habit, and felt slight uneasy at once, because I haven't taken a look at my website for almost 4 months. I input the website address and flipped through the galleries... At the end of the slideshow, I felt much better. I was reminded of the passion that has driven me so far, and will continue to push me forward. There may be long winters and difficult transitions in everyone's life. But hopefully we will not never lose sight of our 'lighthouses'. 
After almost 4 months, my 'Unfinished Projects' folder is empty for the first time, and I am back and ready to go. ;)

Is there a better way to spend a beautiful autumn day?

Entertainment park in summer time; ice rink in winter time--children's paradise all year around.