Introduction

Hey guys! I’ll be doing a comprehensive lesson on reflections, this time in more of a video lecture format than a post or written format. I highly encourage you to listen and follow along with the linked YouTube video rather than simply reading through the article as I’ll be simplifying a lot of what will be said in the video in this post’s writing. It’d be much more valuable for you to go through this in its intended format, but if you do decide to just follow along with just the writing, further explanation can be found in the commentary of the video if you’re ever in need of it.

The Basic Properties of Light (In context of reflections)

Light as we’re familiar with exists in the form of rays that strike the physical objects residing in our space, those same light rays are either absorbed or reflected by the objects, and when they are reflected, they may reflect toward our eyes and into our brains which translate the light into visual information, allowing us to realize the world around us. In the context of what makes an object look shiny, or reflective, if the surface the light bounces off of has inherent shine or reflective qualities, like if it were metal or water, the better and more light will reflect back into our eyes.

And also, the smoother the reflecting surface the better it is at reflecting the light.

The Angle of Incidence

To correctly plot a reflection in a scene, it’s important to be mindful of the concept of “The Angle of Incidence”. The line of sight when intersecting with a surface, the angle it creates would be considered the incident angle, and when this surface that’s being intersected is reflective it outputs that same line of sight equally, creating another incident angle. Equal in, and equal out, in other words, a mirroring effect. This effect can be visualized in the 4 examples on the right: When an object is in the same scene as a reflecting surface, the reflecting surface mimics its environment and even appears to continue the perspective.

Distortion and Warped Surfaces

When a reflective surface is warped, or distorted in some way, it’ll alter the look of what it’s reflecting. Concaved surfaces will stretch a subject and convexed surfaces will compress the subject — sometimes with convexed surfaces, it may flip the reflection in addition to stretching.

Chrome/Metals and The Fresnel Effect

Chrome, shiny balls are perfect in exemplifying the concept of the “Fresnel Effect”. The fresnel effect goes as such: the shallower the line of sight is with a reflective surface the more reflective it appears. Looking at the chrome ball, you can observe that when trending towards the edge it also gradually appears to become lighter in value and this is because the surface is rounding away from the line of sight and so when that happens the shallower the viewing angle also becomes. The fresnel effect occurs more apparently in surfaces that have inherent shine: metal, glass, water, etcetera. and additionally, the shinier or more reflective, the better observed.

Because matter being composed of atoms, and atoms being the parts to reflect the light, atoms will appear concentrated at shallower viewing angles. When a large number of atoms collect closely at a certain area, the better reflective that area also becomes, more atoms = more light to reflect, and the more light reflecting = the lighter in value the reflecting surface becomes.

The Varying Degrees of Specularity

Not all objects are 100% opaque, 100% matte, or even only just completely reflective, usually, it’s a combination of the three: how matte it is, how specular/reflective it is, and how transparent it is. The shiny spheres on the right, you’d probably immediately catalog as just shiny upon first impression, but actually also maintains some matte qualities, these matte qualities adhering to the traditional rendering rules of matte objects, like having a distinguishable light and shadow side, of which is observable on these shiny spheres.

Water and Hair

Because of the free-form nature of water, and it being so sensitive to the various forces in its environment, water will rarely ever be just still. In most scenes water will ripple, it’ll come in waves, it’ll crash, and it’ll all influence how it reflects light because as I’d mentioned before irregularities in a reflecting surface will distort the reflection. In these specific examples drawn, the warped surfaces come in either a repetitive horizontal orientation (of waves) or a repetitive vertical orientation (of hair strands) the former’s reflections and highlights appearing to lengthen, and the latter lengthening width-wise. This occurs because of the fresnel effect, as seen in the drawn peaks and valleys which is observable in both waves and hair strands albeit differing degrees of waves, but still waves. The many peaks where the fresnel effect is at it’s strongest drags out the effective shine beyond the 1:1 reflection produced by an undistorted reflecting surface.

Glass

With see-through glass like a window, a reflection will still be visible though it’ll appear low in contrast with the rest of the values of objects appearing in the scene seen through the window; the reflection will simply be a vague layer lain on top of a transparent surface. A combination of specular and transparent traits.

With the mirror and other highly reflective surfaces, cast shadows will not appear on it because of the lack of matte qualities. Only in some instances like if the mirror was covered in dust or grime would a weak shadow be able to be cast onto the glass.

Reflections will always be a touch darker than the object in reality as there is no surface that reflects light at a hundred percent rate, even in the most reflective surfaces like a mirror some small count of light will be lost by being absorbed or reflected in someplace other than our eyes.

Color and Composition (Extra)

With color we must be sure that adhere to the rule that is “light is additive”, with that said the light source itself will impart its value, its saturation, and its color all onto the to be affected object. In this example the qualities of a white light source add onto the red sphere, dropping the saturation and lightening the value where the fresnel effect occurs and also especially at the highlight where you’d want to make it clear that the light source itself is being reflected to communicate just how specular this object is.

Reflections, particularly mirrors or any other highly reflective surface can be leveraged to extend the frame of an image without actually, literally, extending the frame itself. Because reflections communicate their environment — depending on how cleverly you set up a reflective surface in a scene it’ll capture the things that can’t be seen unless you change the entire composition itself so that thing or things that aren’t visible become visible. Reflections are a great way of enhancing a composition but they’re also great at saving you the trouble of having to change the entire composition to fix a problem that could otherwise be solved with a simple reflection; in the end, it may even elevate the image beyond what was possible if you’d just changed the entire thing without making use of a reflection.

Outro

Thank you so much for taking the time to go through this post of mine! I wasn’t as concise as I’d liked to have been but it’s very difficult to describe a concept without a million other things associated cropping up, so I’m sure there are a number of confusions and points I hadn’t mentioned or missed. If there is anything you wish to be clarified, please ask and I’ll do my best to answer in the comments. Nonetheless, I hope that what I had to share has been of some value to you!