It was vile this morning, pouring with rain and there was appreciable wind chill. On the way back for breakfast I grabbed a bit of stick with a view to focus stacking the lichens growing on it. I have also spent considerable time reading about them. To be honest ninety percent of it I couldn’t understand until I happened across this PDF document. It’s a Scottish Natural Heritage booklet titled Lichens by a chap called Oliver Gilbert. Here is his description:
What is a lichen?
A lichen (pronounced li'ken) is a dual organism consisting
of a fungus and a photosynthetic alga or blue-green alga
(cyanobaterium) which live in close association. The
photosynthetic partner manufactures food for the whole
lichen and the fungus provides a stable, protective
environment for its alga. The fungus forms the main
body of the lichen, and in most cases, the alga lies
sandwiched between upper and lower fungal layers.
Where a lichen has a green algal partner, the green
algal layer can often be seen by scratching the upper
surface of the lichen. Lichens are often quoted as a
classic example of symbiosis - a mutually beneficial
partnership between two organisms.
Other interesting facts:
• some crust-like lichens on rocks have a 'legendary
slow' growth rate, sometimes as little as 0.1 mm
• in undisturbed conditions, some rock-dwelling
lichens can survive to a great age (many hundreds
of years) and are among the oldest living organisms
• many lichens have a remarkable tolerance to
drying out, during which state they can survive
extremes of heat and cold; this means that they can
tolerate being scorched by the sun in summer
months, yet also survive ice and snow, and are
therefore able to grow higher up in the mountains
than other plants.
Scottish lichens are many colours: white, grey, black,
yellow, orange, sulphur, apple-green, pink or scarlet.
Most grow as crusts, some are leafy (foliose), while
others are shrubby. They are completely different from
the mosses and liverworts with which they often grow.
The majority of mosses and liverworts are green, leafy
and photosynthesise their own food.
Thank you Mr Gilbert. Even I could understand this and it did help and hopefully will help in the future.
After breakfast the stick was drying out and the colours were not as vibrant so I wet it again but the reflections were horrendous. I played with the ring flash and ended up just using one side and a polariser but it didn’t make that much difference and I had to take it and the flash off so that I could see to focus. I let it dry off a bit and then tried focus stacking but to be honest f16 worked as well so that was the route I took. I focussed on a macro rail, had 56mm of extension on the lens, speed 160s and the strobe set to full without bias but mode set to ETTL so it used what it needed. The lens is the Canon 100mm macro, it’s a grand bit of kit with aperture from f2.8 down to f33. It’s not brilliant over F18 but as good as stacking.
I’ll try and think of something else for the next post as I realise that they aren’t everyone's idea of scintillating entertainment.