I want to talk a little bit about why it is important to be able to put your camera in the ‘M’ or manual mode and how to adjust the settings to get the image you’re wanting. With today’s DSLR cameras you are able to go out and take a decent picture without knowing the first thing about how the settings are being utilized to create that image. While this is really nice for people who just dabble with photography, I am going to assume because you are reading this that you want more from yourself when it comes to photography.
I am not going to go into too many details in this post about manual mode, you can find those details out here. What I am going to do is show you why knowing these camera/exposure basics is important.
I was out in DC shooting with a friend one night, and after coming out from dinner in Chinatown I wanted to capture the energy of this area. So I set up my tripod and placed my camera on it. In manual mode, which my camera is in 95% of the time, I read the scene and got a meter reading. Knowing I wanted a long exposure to capture the cars and buses whizzing by I knew I would need to keep my ISO low, so I set it on 400. I also had the lens opened all the way up, this was my baseline to get a shutter speed reading.
My initial reading with my f-stop opened all the way up was 1/30 sec for a shutter speed. I know that at that shutter speed I will (almost) freeze a moving car at 25mph as you can see it did here. Not what I was looking for. But the exposure was correct, the scene overall looks fine. But as I said, I wanted to create energy by having the cars moving through the shot. So now I had to determine what I needed to do to get that. Do I open or close my shutter? Do I leave the shutter alone and close the f-stop? What?!?!
Because I know how to shoot in manual I already had the answers as my fingers began adjusting the settings. I knew I needed to slow the shutter speed way down, but by doing that I was going to get an over exposed image unless I closed the f-stop too.
I decided to go with an f-stop of f/13 to not only gain depth of field and let most all of the scene be in focus, but to let less light through the aperture so I could focus on getting the right shutter speed for the image I wanted to create. I doubled the shutter speed and went with a 1 second exposure. Overall the image was a tad dark, but workable, and I did have some light trails. But not what I was envisioning, so I opened up the shutter even more.
I opened the shutter up for 2 seconds this time, but the first image was a bit over exposed, so I needed to close the f-stop some more. I went with f/16 to get the exposure back in line. Now I had better light trails, but still not what I wanted.
I doubled the exposure again, this time to 4 seconds and I closed the f-stop down a bit more to f/18. BINGO! The winning combination! Now all I had to do was wait for enough traffic to create my light painting image showing the energy of Chinatown.
Summary: Because of ALL of the lights hitting my sensor with the street lights and headlights of the cars coming closer to the camera, if I had tried to do this on auto I am sure I would’ve banged my head because the camera doesn’t know what it is you want to do. All it is doing to trying to get the scene to 50% grey, or average. You must have faith in yourself that you are much smarter than the camera. All it takes is learning how the pieces fit in shooting in manual mode…and practice!