For those of you planning on getting your serious macro gear out for this spring — which has finally arrived — you might be wondering how much your macro filters, extension tubes, or bellows increase your reproduction ratio. Here is an easy and simple way to find out.
1.) The first thing you must find out is the size of your camera’s sensor (the dimension in millimeters). For example, a Canon 60D’s sensor is 22.3 x 14.9mm. The first number is the width. You can find your specific camera by simply searching google.
2.) Now, with your macro lens and extension tubes (or filters/bellows) attached, take a picture of a ruler. Make sure you are directly above the ruler and that it is centered. Have the first dash that signifys the beginning of the first inch (or centimeter/millimeter) all the way on the left, touching the left side of your frame. Take the picture. Now find out how much you can fit into your frame. The Canon 60D can fit 6/16 of an inch with my macro lens and other attachments being used (yours will most certainly be different). If you didn’t measure it in millimeters, use google to convert your measurements. In this case, 6/16 of an inch translates to 9.525 mm.
3.) Take this number and divide your camera sensor’s width by it. So for the Canon 60D it would be 22.3mm/9.525mm=2.34. Your answer is your reproduction ratio. This isn’t exactly the most precise way of calculating it, but it’s fast and easy, and gives you a decently close answer to what your reproduction ratio truly is, give or take .03.
Now, as a celebration of our 100th post. A very special video will be coming out soon. It may contain a small giveaway, so stay tuned to our youtube channel (AvidVisionsVideo). You can subscribe here. Since it is finally spring, we will be posting several tutorials on macro photography.