Tuesday, November 24, 2015


This month's tip is about calculating the right exposure, beyond 30 seconds, when shooting in very low light situations, while keeping the ISO at 100....yes, 100.

Here is the scenario

You are inside a darkened church; most of the lights are off. You want to photograph it with a high f/stop (like f/20) and use a low ISO. You are ready to get the shot, but your camera talks back to you. I don't know how your camera talks back to you, bu mine prompts me with 'Lo.' What it's really saying is, "Hey, I'm designed to give you an exposure of up to 30 seconds.You are aiming me at a very dark area, you have me set at f/20, and on top of that you have my ISO at 100. It's going to take more than 30 seconds, but I don't know how much more. You're on your own!" What to do?

Here is the very simple mathematical solution. Rather than sacrifice depth of field coverage (other than f/20) and in order to minimize the chance of noise/grain, I kept my f/stop at f/20 and my ISO at 100. Now, here is the simple left brain calculation.

1) I simply pumped my ISO up to 200. Voila! My camera woke up and gave me a reading of
    20 seconds.   
2) ISO 200 is twice as much as ISO 100, right? Easy math.
3) I simply multiplied the 20 second exposure by 2 (twice as much), which=40 seconds.
4) I simply set my camera to the BULB setting, clicked (using my cable release) and held it for 40 seconds. Voila! I got a spot-on exposure.

If my camera had not given me a reading (a shutter speed) at ISO 200, I would have simply pumped my ISO one more time to 400 and then followed the same math logic. If that had happened, I would have kept my shutter open for 80 seconds (20 seconds X 4).

I took some shots for the purpose of this exercise. I went inside the Unity of Boulder Church Center, with their permission. I intentionally chose the darkest corner of the church for the sake of this exercise.

The following image looks very much the way it looked to the naked eye.


This is the image I got after following the above simple math. I left it untouched for the sake of this lesson. A forty second exposure, f/20, at ISO 100.

This is just one of many tips, creative ideas, and concepts I include in my new book,
RIGHT BRAIN PHOTOGRAPHY (Be an artist first). Contact me for your signed copy.

I highly encourage you to try the above easy solution to difficult lighting challenges. So, go to your favorite building, get permission first, and try it. You will amaze yourself. Have fun.