As Landscape photographers, we know that capturing reflections of our scene in ponds, pools and rivers is both compelling and addictive and adds depth and interest to our compositions.
One of my favorite images I captured in 2020, was the reflection of a bare white tree in the icy banks of the Merced River in Yosemite. While processing the image I flipped it vertically 180 degrees and realized the image now was even more intriguing. By changing the orientation I changed the viewers assessment of what they were looking at. No longer an upside down refection the way we usually see them, but a complete change of perception and point of view.
MERCED RIVER YOSEMITE
By turning this world upside down, what was expected now becomes a surreal and an artistic echo of the original scene. Taking a simple idea and creating a compelling image.
Planning a well composed and and focused reflection is not always as simple as is "appears on the surface" (pun intended)
Usually in landscape images we are tack sharp in the foreground and focus tends to get softer as we go into the scene. When flipping an image, that slightly out of focus portion is now the foreground. Keep that in mind. It can still work very well in this abstract approach but sometimes can appear a bit odd.
OK...here's the geeky Bit
The reflection DOES NOT live on the surface of the water.
So when focusing
Only the subject is in focus OR only the reflection is in focus.
If both the subject and reflection are far away and your shooting with the narrow aperture then both the subject and its reflection are in focus.
A reflection is always farther away from your camera than your subject is.
The distance the camera needs to focus on to get a reflection in focus is equal to the distance from your camera to your subject PLUS the distance from the subject to the reflective surface.
TWO JACK LAKE
Hyperfocal and depth of field come into play. If the subject is further away from the reflecting surface, objects closer to it will be more out of focus.
You need to follow light through its entire optical path up until it enters the lens. Even though an image appears to be on the surface, it is in fact far from it.
The light from a reflection is actually traveling to the surface, then from the surface to the lens.
If you measure only to the water, you will focus on the surface, but not necessarily the subject reflected within it.
Your best bet to get both your subject and its reflection in focus is to use as small an aperture as possible. This increases the depth of field, which means that a greater range of distance from your camera will be visible. However, if your reflection and subject a close to the camera your safest bet is to take one to focus on the reflection and one for the surrounding areas.
If you want the whole reflection evenly focused use a narrow aperture like f/16. Conversely, if you want an ethereal softer look open up to 2.8 and decide what in that reflection you want in focus.
I use manual focus to make sure the parts of the image I wants to emphasize are sharp. Is it the leaves on the surface of the water or the reflection of the tree? Auto focus may produce some interesting but unintended results.
OWENS LAKE CA
A polarizer can be useful for reducing glare. Although we usually use them to remove reflections , just rotate the filter slightly, to reduce the glare but leave your reflection intact. Often when using a polarizer I will take a series of shots at various strengths. I may apply greater polarization in one part of the image and less in another, plus it gives me more options in the final process.