Album cover
Album cover
Album cover
Emily Lee
High Dynamic Range
The human eye has the extraordinary ability to be able to see detail in both the highlights and the shadows when looking at a scene. A camera however, does not have such a dynamic range and is only able to capture details within a set spectral range. This results in either the clipping of shadows or highlights producing either under or overexposed image, or an images exposed for the midtowns that lacks detail from both extremes.
However, there does exist a way to produce images containing details in both the highlights and the shadows. This technique is known as HDR (High Dynamic Range). By taking a bracketed exposure - a series of images taken with varying stops of light entering the camera - you enable yourself to produce a composite image which uses parts of each photograph in order to show a higher dynamic range i.e. have more detail in the light and dark areas.
When producing an image of this sort, you can use photoshop’s option of ‘merge to HDR’ (file - automate - merge to HDR) to import the stack of images and allow the computer to overlay them for you, choosing the sections containing the most detail from each image and producing a composite. The resulting image can appear almost fantastical as it contains a wider spectral range than even the human eye can comprehend due to the inclusion of the dynamic range of multiple separate images. The level of clarity becomes almost overwhelming.
Class response
These images were taken as part of a practical lesson in which we experimented with HDR. We were challenged to produce 6 HDR images of 4 set locations and 2 free choices around the school. In order to produce these images I used a fixed ISO of 250 (to reduce grain) and aperture of F4 (to ensure that the focus was the same for each image). I then used the third point of the exposure triangle - shutter speed - to control the exposure of the image. This enabled me to produce a variety of overexposed images that clipped out the highlights but showed detail in the shadows, and underexposed images that clipped out the shadows but showed detail in the highlights that I could import into photoshop to produce a high dynamic range photograph.
Corridor
For this location, I decided to make use of the leading lines produced by the glass corridor. These lines draw the viewer to the centre of the image (the vanishing point) at which there sits the orange glow of indoor sodium lighting at the end of the corridor. This section proposes a juxtaposition not only between the indoor and outdoor elements of the image, but also the complementary colours of blue and orange which sit opposite each other on the pigment based colour wheel.
I took three images of ISO 250, F4 and shutter speeds of 1/25, 1/125, and 1/800 respectively in order to produce the variation required to produce the HDR image in photoshop. After importing these images, I made use of the Scott5 preset which boosted the vibrance and saturation to make the image seem more hyper realistic.
Common Room
In this image there are some evident leading lines created by the chairs and the windows, forcing the viewer’s eye to move mostly along one side, thus hiding the slightly more messy right hand side of the image. These lines also give a sense of spaciousness to the room, leading the viewer’s eyes far away down to the other side, making it seem like a much larger space than it is. This effect is also implied by the lack of people in the room, hence more empty space is visible, making the image lighter overall.
To produce this image, I took four exposures at shutter speeds of 1/6, 1/100, 1/500, and 1/3200 and overplayed them together. Due to the way in which the light reflects onto the floor in each image, the colours are somewhat disrupted, producing an extremely saturated section that distracts from the rest of the image.
Courts
Here, I attempted to use a low angle in order to emphasise the leading lines produced by the boundaries of the court. This angle allowed me to create a composition of approximately 2 thirds sky and 1 third ground, however the position of the camera was not able to be fixed by a tripod, only a precarious propping up of the lens to produce a slight incline. This set up resulted in slight movements between each shot through my pressing of the shutter button. Despite my efforts to reduce this movement by using a timer, the slight adjustments between each shot meant that the images were not quite correctly aligned and there is some consequent ghosting.
Additionally, where the computer has combined the four separate images (of exposure times 1/100, 1/320, 1/2500, and 1/8000) there was some evident discolouration around the edges of the trees and the sun. This green/blue aura is known as chromatic aberration and occurs where the computer cannot handle the intensity of the highlight.
Hall
In this image, I attempted to use the framing of the Christmas tree to produce a seasonal inspired HDR image. I used the tree to cover roughly 1 third of the image on the left hand side producing a foreground interest. Unfortunately, I am not quite happy with my angle here as I feel that it could have been improved slightly by moving the tree diagonally up to the left in the frame in order to make it less dominant in the image and create a more interesting focus point of the glittering bauble by placing it on the top left cross of the rule of thirds. I would also liked to have been closer to the bauble to make it larger in the frame and hence again, more of an interesting subject. Additionally, the slight alteration of angle would have eliminated my reflection in the bauble above, which I did not notice whilst taking the shots.
The colours of the image are somewhat dull, not due to the saturation of the image (as I boosted this during the creation of the HDR) but purely down to the room itself. As a result, I feel that I could’ve again found a slightly better angle containing a wider variety of colours in order to better represent the hall. However, the background is kept from being cluttered by my use of F4 which created a small enough depth of field to centre the attention on the bauble, rather than letting the mess of the background draw the focus away. Despite this, the small aperture did also affect the appearance of the shot as a whole, making it seem flat due to the lack of detail infant of and being the focal plane. The sharp drop off due to a large distance between the foreground and background of the image creates an almost child-like composition, the light aura surrounding the tree adding to the implication of a poorly put together image.
Quad
This image is my least favourite of the set of six. I had attempted to use creative angles in order to present the areas of the school in ways we had not thought about before, however this angle did not quite work out in the way that I had expected it to. I chose to shoot from below the quad so that I could use the framing of the buildings around it in my image. I also used the additional framing of the trees to draw the the attention to the students, at first unnoticed, hidden in the grass. I had planned to introduce motion into my HDR to see what effect it would have on the image, however the students didn’t move greatly between each shot, hence producing only a slight ghosting around the edges of the images.
Furthermore, in the individual exposures (at shutter speeds of 1/50, 1/100, 1/500, and 1/3200) the resolution was high enough to capture the details of each colour in the highlights and shadows. However when layered all together in a HDR image, many details were seemingly lost, especially in the highlights where significant banding is visible.
Bus Bay
In this photo, I made use of the metal barrier between the path and the road to create a leading line in my image. Emanating from the bottom right and moving diagonally up to the left, the direction echoes the line of the road and helps to draw the viewer’s eye to the central car made ghostlike by the high contrast present in the HDR production. The overlay of the multiple exposures warps the colours somewhat where the different cars overlap. This effect is quite similar to the work of Michael Lee in his technique of ‘abberational expressionism’.
Unfortunately, the chromatic aberration is again visible in this image around the edges of the trees along the upper third of the image.
Summary of my findings
As a result of my experiments I discovered that having leading lines in the image helps greatly to preserve the depth of the image, reducing the flattening effect created by the post, production HDR effect. Having an abrupt change in focus (i.e. having the background a great distance away from the foreground) can help to hide clutter in the background, however you lose out on vast amounts of detail, making the image look more amateurish.
Also, it is far more difficult to produce a HDR image outside with large amounts of sky in the image in comparison to greatly shadowed areas. This might seem like a great contrast for a HDR, but the highlights become easily blown out, causing chromatic aberration around the edges. Hence I concluded that when taking bracketed exposures for HDR images, it works far better to use brackets of even distance, rather than the full extent of the highlights and shadows in an attempt to produce an average of the two. The slightly less varied, yet still distant exposures will allow for less clipping in the resulting HDR, making it seem fantastical, but without producing an image with a spectral range so wide that it is abhorrent.
Lastly, the angle of the shot is absolutely key. This is true for all kinds of photography techniques. It is vital to consider all of the rules of composition and check that they work together in order to create an effective piece.
Michael Lee - HDR Expressions
"Venetian" by Michael Lee - n.d.
Michael Lee began his artistic career as a painter, supplementing his work with photography. In order to be able to paint better from his photographs he invested in a Canon 5D MK III and since his discovery of the cameras HDR function, he has been fascinated by the possibilities of cubist compositions as a result of this feature. Unlike most other HDR photographers, Lee uses the function not to produce a wider spectral range for a dramatic landscape, but to capture impressionistic responses and represent the feeling of immanence with the scene captured.
In the series ‘HDR Expressions’, Lee focuses on capturing motion and ensures that the composition of each image taken to be used to produce a HDR image is different. This movement between each of the bracketed exposures produces a peculiar effect when all the images are combined, creating something of a colour storm where the various details overlap in different images. I quite like this effect - known to Lee as ‘abberational expressionism’ - as the violent mesh of colours effectively produces a busy atmosphere, reflecting exactly the ambience of a street scene such as the one pictured here. This encompasses the viewer, making them feel as if they are part of the image.
There is no doubt that this image is an expressionistic piece, due to its striking surrealism and cubist qualities. But despite the eclectic mix of colours bamboozling the viewer, Lee is still able to present a likeness to a busy street. The use of images with different perspectives allowed the production of an image with people of varying sizes within the frame, adding depth to the image, and allowing the viewer to be further absorbed into it.
"Venetian" by Michael Lee - n.d.
Similarly to Lee, my own HDR image captures motion due to the small movements of the composition between the individual shots in the bracketed exposure. However in Lee’s case, both the positions of the camera and the subject matter were altered between the images thus producing greater overlaps and hence a greater exaggeration of abstract forms in the resulting HDR. My image contained only minimal overlaps due to the minority presence of the moving parts in the image. Despite this, when cropped down there are much clearer areas of Lee’s technique of ‘abberational expressionism’, though they are still not as dominant as Lee’s work.
HDR of the 6th form common room
HDR combo
Here I chose what I believed to be the most interesting parts of my HDR images and amalgamated them into a single 3x3 grid image. My choices were based either off of interesting compositional features, or intriguing effects of the HDR production in the image. For instance, I chose the top left image of the grid due to the strong leading line cutting through the centre, and the subtle complementary blue and orange colours. However, I chose the bottom middle image of the common room due to its slight ‘aberrational expressionism’ created by the overlay of multiple images with slight movements between frames.
I chose a square crop for my images in order to make the size of the image less distracting (as the crop of an image changes the way you see it). The use of a uniform crop allows the viewer to see only the content of the image, rather than change their view of the image due to the way that it is cropped. Additionally, the clean cut squares also pack together much neater in a grid, thus producing a more aesthetically pleasing combination of images.