Extreme Macro Photography
This article is describing the technique I'm using to achieve high quality extreme macro photos, for magnifications beyond 3x, up to 10x (possible up to 20x).
This means that the subject frame is between 3 and 20 times smaller than the physical sensor dimensions (i.e. 22.2mm for APS-C).
This also means that creatures even below a few millimeters in real life, can almost fill the whole screen, revealing amazing, incredible details, unknown to the naked eye!
Here are a few examples:
The best way to achieve quality at these high magnifications is through microscope objectives.
All other popular macro techniques, based on reversed lenses or lenses + extension tubes/bellows, will only give acceptable results for magnifications up to 2x, probably less. Heavy diffraction will exponentially destroy the quality, if one attempts magnifications beyond 2x, with such setups.
Disclaimer: I don't own a dedicated Canon MP-E 65mm f/2.8 macro lens, but I read reports about good results obtained with it, up to 5x, although the same reports still give microscope objectives the edge in terms of IQ, in the 3x-5x magnification range.
In general, there are two types of microscope objectives:
- new types - infinity corrected objectives - must be used with a 200mm tube lens
- old types - finite objectives - can work with extensions tubes or bellows.
My choice was to work with the new, infinity corrected objectives.
Instead of a dedicated 200mm tube lens, I realized I can use a quality zoom lens I already own: Canon 70-200mm f/2.8 IS II. It works well when zoomed to the max (200mm) and focused at infinity.
I also own two Nikon CFI microscope objectives:
- Nikon CFI 4x 0.20 Super Fluor
- Nikon CFI 10x 0.30 Plan Fluor
(CFI = Chromatic-aberration Free Infinity)
The objectives are attached to my zoom lens with two adapter rings: 77mm->52mm and 52mm->25mm (which is the standard thread for the new Nikon CFI objectives).
Here is my setup showing a microscope objective attached to a zoom lens:
When buying microscope objectives, besides the type and the nominal magnification, two additional characteristics are important:
- working distance (WD). If the WD is too small (eg < 5mm) there is not enough space between the objective and the subject, to insure proper illumination
- numeric aperture (NA). The higher the NA, the more details the objective can resolve (sharpness), but at the same time, the narrower the Depth of Field (DoF) is.
As mentioned above, microscope objectives offer superior image quality, but the drawback is the very narrow DoF (depth of field).
This is why, the only way to obtain usable images with microscope objectives is through focus stacking.
We are talking about focus stacking using, for my objectives, 20 microns step size for 4x magnification and 5 microns (!!!) step size for 10x magnification.
This is why, in most of these cases, manual focus stacking is very challenging, if not impossible. Automation is key for success.
There are several good and affordable automated macro rails on the market (google them).
However, I chose to build my own, around these main components:
- a Velbon Macro Rail (since it has a good native accuracy of 4mm/rotation)
- an Arduino micro-controller (relatively easy to program)
- Servocity structural components, to ensure mechanical accuracy.
I decided to use continuous LED lighting, instead of flashes, because I like to see what I'm about to get. Besides, when taking sequences of hundreds of photos, even the best flashes might misfire. The trade-off is longer exposure times: 0.5-1s. This also means absolutely no vibrations, no walking around the system and no big trucks passing nearby.
Preferably wife and kids asleep! ;)
Finally, stacks of several hundreds of photos are combined and retouched with a dedicated stacking software and fine-tuned in PS.
Obviously, this whole process requires a lot of patience and some financial investments, but the results are very rewarding and often beyond expectations!
I often point out that photographers are ready to spend tens of thousands and travel to the other side of the world to photograph wildlife, without realizing that the most fascinating creatures might live in their backyard, or the park across the street from them!
This micro-world is truly fascinating! Too bad most of us are oblivious to its beauty!
Photo credits: Mihai Andritoiu.
Nature and Wildlife Photography