Lighting for Nikon macro beyond 1:1
Once again, my photographic opportunities of late have been very minimal because of work, but I have now, however, set myself a photographic challenge for December.
I have set myself to try to produce an inexpensive method of flash diffusion for flash-as-main-light macro work for beyond life-size magnifications. Anyone who has been doing much macro work will know that lighting is one of the most important and often tricky aspects of this type of photography to master, so practice and experimentation never goes amiss.
My 200 f/4 micro lens goes to 1:1 at minimum focal distance, and extension tubes take this up to 1.3x, or 2x if I use DX-crop mode. This obviously isn’t the best lens to use on Nikon to go beyond life-size (a 60 or 90mm lens would be more obvious, being less Heath-Robinson and providing more magnification with extension), but it’s what I’ve got at present, and with my D800E the extra resolution allows very fine detail.
Canon-users are much better served for beyond life-size, since they have the dedicated MPE-65 lens which has built-in telescopic extension taking it to 5x life-size all by itself; they also have the twin-flash MT-24EX.
Lighting wise, Nikon has an equivalent which is in some ways more advanced and in other respects seemingly less well thought-out for high-mag macro work. The R1C1 kit is wireless and seemingly easy to use, but it is very expensive, and rather fiddly. Also, the adapter ring for the lens-front isn’t as well designed as the Canon equivalent, and the attachments and batteries needed for the flash heads are non-standard and inflexible.
(See this link for a useful comparison: http://orionmystery.blogspot.co.uk/2012/10/mt-24ex-vs-r1c1.html).
Moreover, it also appears that both of these twin-light macro systems require some extra DIY light diffusion to get the best out of them. It’s often the case that high-magnification macro subjects such as flies, or small bugs, have highly reflective exoskeletons which seem perfectly designed to capture the minute flaws in a macro-photographer’s lighting technique – producing nasty or overblown highlights for the unwary. I’ve looked into this for some time, and it appears that the best results come from a two-stage diffusion technique, with the final layer of diffusion as close to the subject as possible if you desire to remove the unsightly highlights as much as possible. (In other subjects, a certain amount of flash reflection is actually desired, as in the case of jumping spiders, where their large eyes need relatively large catchlights to pop properly.)
As such, I designed an initial DIY solution, to modify the light from my SB600 already diffused with a Micro-Apollo softbox.
It consists of the following, as illustrated in the two following shots:
1x sheet of thick polythene packing material from Wimberley product packaging
1x curved cut-out from 1.5 litre milk bottle.
The bottom of the milk bottle is joined to fit loosely around the lens with a small piece of velcro. The Wimberley packaging diffusion material is then attached to the milk-bottle plastic with 2 small pieces of velcro at front and back. A Velcro tab on the top at the front then attaches to a velcro tab on the bottom edge of the softbox, to hold it in position and out of axis of lens.
The flashgun is held in position pointing vertically downwards over the end of the lens using a Wimberley macro bracket attached to the L-bracket vertical on the camera body.
Below are some comparison images taken both with and without the additional diffusion, using my trusty Swiss Army knife as a useful reflective subject. All are taken handheld at ISO 100, 1/250 f/16 with a polarizer fitted to the lens, and using iTTL flash with +1.3EV compensation, or +1.7 – +2.0EV with the added diffusion (this will be subject to modification subject to ambient conditions). All images are reduced to 1200 pixels width and sharpened slightly – click on the images to open the 1200px width.
These first two shots are at roughly 2x life-size. The second of these was taken without the extra DIY diffusion, and the lighting is harsher with blinking overexposed highlights at the bottom of the frame.
This second pair of images shows the detail from the penknife’s pliers tool, again at about x2, showing very different lighting effects. The first is with the extra diffusion, the second without.
Finally, a pair of shots taken in FX-mode for about x1.3. This time, the first image is taken without the extra diffusion. THe lighting is a little harsher, and the harsh reflections along the bottom edge of the pliers are blown (blinking highlights in camera). The second image is less contrasty, but has no blinking overexposed highlights.
Hopefully I’ll have further updates in due course when I’ve tried the system out some more. The effects are at times subtle, but worth the effort if you really after properly exposed macro subjects without distracting blown highlights which are difficult or impossible to rectify digitally afterwards.
Not bad for an hour’s messing about on a Sunday morning!