Sunday 21 December 2008

My usual technique for shooting macro on the monopod is to have the camera on manual focus, set the focus point and then rock the camera forward or back until the desired part of the image (e.g. the eyes on a spider) are in focus. The monopod means I can hold the camera fairly steady with just my right hand. This frees my left hand for holding foliage out of the way or even steadying the foliage, particularly if there is wind around. The problem I have when holding foliage with my left hand is I have no way to adjust the focus if I want to move closer to fill the frame more or further away because the subject changed its angle. I have recently discovered that I can use the AF-ON button on my Nikon D300 to make focus adjustments but still use my manual focus technique for the actual focusing.

For macro photography it is better to use manual focus so you can control exactly what is in focus, especially when the depth of field is shallow. The default behaviour of the Nikon D300 when in autofocus mode is to focus when the shutter butter is depressed half way. This means you ideally need to the camera set to manual focus and you have to adjust focus with your left hand. As mentioned above, this can be difficult if your left hand is holding something. Many makes and models of cameras have an AF-ON button or equivalent. This button can be used with your right thumb for focusing. Custom setting a5 on the D300 allows disabling the focusing on the half shutter depress meaning that AF-ON is the only way the camera will focus. This means that if you don't press AF-ON, the camera is effectively in manual focus, but, focus can be adjusted when required using the right hand only, leaving the left hand to continue doing whatever it was doing.

I tried this yesterday and while it will take a bit of getting used to, it worked very well. All I had to do was use the AF-ON button to adjust the focus such that when in focus the subject was framed the way I wanted it. Here's a shot I took using the technique where I managed to fill the frame while still holding the foliage on which the spider was standing.