Some Macro Advice Using Flash

Hi everyone!

Thanks for dropping in to my latest blog where I’m going to show you a cheap way of improving your macro photography using a standard flash gun to stop those blurs and lack of focus depth in your macro photography.

First lets explain the difficulties of macro photography.
When working close up with a macro lens you are working with a very shallow depth of field (focus), also the closer you are the less light you have to work with even in some cases you’ll be working in your own shadow. This means it’s difficult to get shots of say an insect for instance and keep all the subject in focus. To achieve more depth of field you need to make the F stop (or the aperture) of the lens smaller, this then will get you increased depth of field. However when you do this you still need to get the same amount of light into the camera to get the shot exposed correctly and this means reducing your shutter speed, increasing your ISO or both! Reducing your speed means that any movement will cause blurs and increasing your ISO will mean you will start increasing the noise and grain introduced into your shots. There are a few other factors to take into consideration also. Using a Full frame sensor camera the depth of field will be shallower than a smaller sized crop sensor camera and also the longer the focal length of the lens the less depth of field you get than a shorter length lens. 

Getting technical? OK don’t worry too much if you cannot get your head round that! Basically if your getting shots that you struggle with the focus and blurring when taking macros those are the reasons why.

The answer to the problem is we need to bring in more light, in this case flash. There are many specialised flashes designed for macro, twin headed flashes, ring flash, ringlites, etc, etc. All have there fores and againsts but there are cheaper options to try out before going to the expense of buying specialised flashes, and methods that sometimes work better than the expensive methods in some cases.

First of all you need a flash that attaches to your camera. (if you haven’t got one you could use the same technique with your pop up flash on the camera mind). Next lets see what this will and will not do! It will allow us to get more light, however the light would be harsh and not very flattering and depending on how close you are to the subject the length of the lens will cause a shadow at the bottom of your image or may totally miss lighting up any of the subject. There is an easy way round beating the problems we just need to diffuse the light and bounce it onto the subject and here is the easiest of those techniques to set up.

1. We need something to bounce the light. That can as simple as a piece of white card, plastic or in my case a piece of flexible packaging foam. The foam is nice to use because it does not have a smooth surface it’s bubbly and uneven which will help diffuse the light more giving a much nicer natural effect.

Notice that I’ve threaded some thin garden wire along each side (often used for flower arranging too you can get it from garden centres), it doesn’t need to be fancy it just helps to bend the foam and keep it in place. Next we sellotape this over the top of the flash so it protudes past the length of the lens. Bend the end of the reflector so it bounces the flash downwards towards the subject. Occasionally you can adjust this as the subject may be closer or further away.

Simply hold it in place with a rubber band or some sellotape. I’ve used sellotape in this case but a rubberband may be better if you have one the correct size. OK it looks crude, it is but it does the trick and will allow you to get better shots and you can adapt on this method to come up with something even better, Many top macro photographers use simple methods like this to get nice diffused lighting. I’ve also added a Stofen flash diffuser on the end of the flash but you don’t have to use this even a thin single ply bit of toilet paper and tape can do the same if required!

So now you need to setup. Put your camera in Manual mode and set your aperture from around F10 to F18 (experiment). Select a shutter speed of around 1/125th of a second to 1/200th of a second (depending on what speed your flash will operate on) Set the ISO to 100, don’t use auto ISO you want to get the best shots and light from the flash will mean you can work and get all the settings you require to do so. Check if your flash has exposure compensation and also set the mode to TTL metering if possible. If you have both and your shots are too bright or two dark experiment with the compensation till you get what you want. With all cases with macro photography you need to experiment to get the best shots there will be a few that don’t hit the mark but I think you’ll get a much better percentage of good shots using this method. Below are just a few I took with this setup.

© Les Arnott 2013