Ring Flash – Image Stacking

My previous foray into the woods working with a ring flash, and using the Canon 100mm f2.8 IS Macro on a 5DMkII body had turned out to be reasonably successful. The greater working distance afforded me, using a 100mm focal length lens, helped in not obstructing natural light from reaching my subject, often a problem when working very close up, where even your own equipment may cast a shadow on the subject. The ring flash being employed to provide either fill in light to the shadows, or became the primary light source in dark environments.

What was apparent from the results was the lack of depth of field, even using an aperture of f16, in particular where there was significant depth in the subject, front to back. Image stacking should be the ideal tool to overcome that problem, however combined with flash, ring flash or conventional flash units for that matter, could cause a problem due to the recycling time of the flash to fully recharge between shots.

As it turned out I need not have worried for two reasons. Firstly there is a slight delay of a second or two between shots while the lens is stepped forward to its new focus point by the connected laptop software, and secondly, working so close to my subject only required a flash output of between 1/4 and 1/16 power. The flash being used in manual mode, as you have plenty of time to decide on the optimum power output for any given scene and adjust the settings accordingly.

On a more practical note, ring flash units are not inexpensive items, so not something  you would go out and buy before at least discovering how often it would be used in your style of photography. Fortunately there is a viable alternative, LED Macro ring lights which are a fraction of the cost of a ring flash unit, often between £20-£30 for the full kit including a set of 6 adapter rings to attach the ring light to your lens. It still rankles that a single adapter ring for my ring flash cost £29 and was an optional extra! As with anything in life there is a caveat, in that LED lights are far less powerful that flash so they do need to be used close to your subject. On the plus side, being a continual light source, it is much easier to notice any annoying highlights produced at the taking stage, thus allowing you the opportunity to adjust your position and minimise the effect, and over the years I have had good results from both types of ring light.

Looking for a subject close by I had to look no further than my back garden, as I happen to have a dead Laurel tree not ten feet from my kitchen door, and looking carefully I notices signs of fungi growing at its base, and just 48 hours later there was a large patch of fungi ready to photograph.

Below are two examples both without and with flash. I used the flash more as a fill in than a main light source, to just add a little extra detail in the shadows. As for which is better? Its very subjective, but I’m happy with the first image without flash, even with the darker stems, in the close up image however, the flash has lifted the composition giving the fungi more modelling which I much prefer.

All taken at ISO 100, f8, White balance set to ‘Daylight’, RAW format, Flash 1/16 power.

(below) No flash

2017-09-23 01-33-57 (C)-Edit

(below) With flash

2017-09-23 01-41-26 (C)-Edit

(below) No flash

2017-09-23 01-58-39 (C)-Edit

(below) With flash

2017-09-23 01-25-06 (C)-Edit


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