DSLR, Understanding Aperture, ISO, & Shutter Speed

Back in December, I finally dumped a big chunk of my hard earned dollars for a new camera, a DSLR to be exact. Ironically, I used to make a joke of those who carries a big camera around are doing so to compensate their lack of size in the “other equipment”. Well, here I am today, joining the club.














I chose the standard lens package, EF-S15-85mm IS, as I though that zoom range is already more than enough. Just 3 weeks after that, I dumped another $400 for 75-300mm USM lens!

When I bought my Canon EOS 450D, I thought how hard can it be to use a DSLR? It’s still a camera, so the “point & shoot” tactic would still work, right? How sadly wrong I was.














1 month and a hundred books of photography gone by and up till today, I am still trying to grasp the whole function of DSLR. I probably read more books in that month alone, compare to the whole year back when I was in university.

I hope the information I share below is useful for those who find the explanation in the Wikipedia too technical.

Basically there are 3 things to look out in using DSLR.

1. ISO
2. Aperture (usually known as f stop)
3. Shutter speed

I found the explanation on the net is a bit too technical for a newbie of DSLR world like me. However, I found Canon Japan, provides a really easy to understand explanation, pictures, and examples.














1. ISO = film sensitivity
Following Canon’s website, let’s imagine your film as a cup. The higher the ISO, the smaller the cup

2. Aperture = the amount of light
Let’s imagine the light as water. How much water you want to put into your cup?

3. Shutter speed = exposure time
Finally, how long you want to open the water tap, letting the water to flow into your cup.

After that, everything else is logic. To get more lights, say for night photo, we can either increase the aperture opening or lower the shutter speed. In another word, either open the water tab bigger or letting it open longer.

As for ISO, I prefer to keep it down to 400 for daylight shooting and 600 or 800 for night shooting, and adjust the aperture & shutter speed to reach the picture I want. This way, I have lower “noise” that may appear in high ISO pictures.

The last advise is go out there and do the practical training rather then staying inside eating books after books, like I did.