When it comes to the subject of tsuba appreciation, lighting impacts our ability to appreciate the subtle beauty found in fine iron sword guards. For the unqualified study of tsuba, and for the display of tsuba for basic visual access and observation, the standard is to present the guard on a flat surface such that the viewer is looking down at the piece. The lighting used is most often relatively bright, harsh and glaring, usually coming from somewhere in the area of directly above the sword guard. Such lighting certainly accomplishes the task of illuminating the tsuba for purposes of observing and identifying detail in the metal, workmanship and condition of the guard, as well as in its general design and in the subject or motif featured.
In the Japan of four centuries past, there were indeed many qualities of light, but much of the time, by design, this light was experienced as subdued, filtered, softened, dampened and indirect. It entered dark spaces through small entrances and windows, through the paper of shoji, through the clouds, and through the leaves, bamboo, maple and ginkgo. The wood comprising the bulk of the Japanese home and work space made for darkened recesses and shadow-filled corners, even in the middle of a summer day, the low hanging eaves only providing more and darker shade for the interiors.
One has to recognize the Japanese sensibility regarding light and dark, shadows and illumination, and the interplay between them and the effect such ambiance has both on the space itself and on objects within that space. This bygone age is the time in which traditional Japanese arts, as we would recognize them, were conceived, designed and created. The skilled tsubako, being aware of his work as holding great expressive and evocative potential, and being conscious both of how the specific metal he was working with and how his workmanship itself would allow that potential to manifest, would also understand that this promise would be realized differently in the diverse lighting in which the tsuba would be worn and viewed. He would create the sword guard accordingly, fashoning it to take advantage of these many varied sorts of illumination. The tsuba coming out of the workshop of the tsubako is thus made deliberately, with awareness, with the guards potential to interact with different qualities of light, a key consideration in the construction, design, texture and finishing of the tsuba. The user of the tsuba would likewise have a conscious appreciation for the ways in which the tsuba would express its qualities in his travels, travels which would likely include a wide range of light sources, intensities, colors and degrees. The user of the tsuba would be using it as part of his koshirae, another factor to keep in mind when considering the play of light on the iron of the guard. For both maker and user of the iron sword guard, the conscious appreciation for the beauty of the iron could not have been accomplished without a parallel awareness of the ways in which light would strike that iron, and the ways in which its form, texture, color and patina would be affected, moment after moment, by the ever-changing dynamic of light on metal. The effect is that the tsuba is brought to life by the power of light. In different angles, intensities, colors, tones and degrees of light, the tsuba expresses itself. This was the context in which sword guards were appreciated, by both bushi and tsubako in the Japan of those several centuries past.
To appreciate the tsuba made in the darkness of pre-Meiji Japan really requires us to see them in soft, filtered light. We may not be able to access traditional Japanese houses and spaces very easily, but at the very least, we need to be cognizent of the fact that the way in which we have been conditioned to see sword guards over the past decades, is certainly not the way they were imagined, seen, and engaged with at the time of their actual creation and use. The 'Western' way of tsuba study certainly has its advantages, but for a more 'Japanese' appreciation, it is only in the quiet, soft, subdued illumination that the iron sword guard's subtler features can and will find their fullest expression and appreciative reception.
Reference: 'Musings on the Importance of Lighting in Iron Tsuba Appreciation' by Steve Waszak.