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Lens Aberrations in Photography: Good or Bad?
In my previous article, What are Lens Aberrations, we got to know the primary types of aberrations. Now it’s time to see what they mean in practice and address the elephant in the room in the form of a vital question: are optical aberrations good or bad for photography?
There are quite a number of differing opinions on this matter, so I’ll try to argue my own, which is based on 15 years of practical experience both in artistic photography and purely when plying my trade. Throughout this time I’ve managed to utilize around 200 different lenses with different image characteristics and different levels of aberration intensity, 40 of which remain in my collection to this day and still find regular use.
The different opinions held by various photographers regarding photographic aberrations are mostly divided into two camps, one somewhat larger than the other, but both boasting numerous supporters.
Members of the first camp claim that the less intense the lens aberrations, the better the lens (a lens without any aberrations at all being the ideal). Members of the second camp hold that lack of intense aberrations also results in a lack of “lens image” since both the character and image of a lens are defined by the intensity of residual aberrations (meaning that a lens without aberrations is ideal, if what you’re looking for is an “ideally boring” lens).
Jumping ahead a bit, I’d like to note that my own personal observations have shown more simple “craftsmen” among the first camp and more “artists” among the second camp. I’ll be using these two terms to refer to these two groups throughout the rest of the article.
Though there is also a third, quite sizeable group of so-called “techies.” Techies are primarily interested in photographic technology rather than the photos it helps produce. To them photos generally exist simply to analyze the pros and cons of any given lens or camera. They spend their time taking photos of various make believe worlds and fancy subject matters with high levels of detail, or just any photos at all so long as they boast beautiful bokeh and a pretty overall image. In this case everything depends on the level of “techieness.” As long as it manifests in moderate amounts, such experiments can be useful both for those performing them and others interested in the topic at hand. But going over the top and obsessing with it is, in my opinion, a dead end in the field of photography that prevents you from developing a true photographer’s identity. Then again, there’s always the option of going the route of becoming an optical constructor.
Anyway, let’s get back to trying to answer the main question here: when are aberrations welcome, and when should they be avoided?
Primary Appraisal Factors
In my opinion, the matter at hand depends on a number of key factors:
1. Photo type: artistic, applied science, aerial, etc. Aberrations are generally most tolerated in artistic photography.
2. Insome genres of photography residual aberrations are acceptable or even desired, while in other genres aberrations are highly opposed. We’ll get to this in more detail below.
3. Personal tastes and subjective appraisal of shots. This includes how interested you are in pictorialism, which is entirely based on the use of soft imaging optics with intense aberrations.
4. Artistic perspective, and a feel for aesthetics, either natural or acquired. This includes both knowing the history of the arts and being introduced to various graphic styles and directions, as well as knowledge of various genres and their most renowned representatives. Not to mention visiting museums, expos and so forth, and not only those dedicated to photography but others dedicated to different plastic arts as well. All of this allows you to answer a simple yet simultaneously complicated question: is what I’m seeing before me right now truly beautiful and depicted in harmony, or not?
5. Experience using different types of photographic optics. This provides you with more options for comparison and analysis.
Let’s take a look at the most popular genres of photography and check out how well they mesh with aberrations.
The typical and most common “classic” landscape photos shot by means of wide angle optics generally go through a process of removing all residual aberrations that can be removed. Special attention is given to correcting curvature of field (resolution and sharpness along the edges) and distortion (with the exception of FishEye lens shooting).
Pic. 2. Classic landscape. The less noticeable the residual aberrations, the better.
However, at the same time an artistic landscape approach welcomes the use of lenses with residual aberrations, including intense spherical aberrations (monocle), distortion (FishEye), and curvature of field (Petzval lens).
Pic. 3. Pictorial landscape shot with a monocle. Aberrations set the mood and create an atmospheric shot.
Architecture, Interior Photography
This approach generally calls for as much aberration correction as possible as well.
Pic. 4. Interior of Saint Basil’s Cathedral.
The exception, again, being artistic photography (mostly when it comes to architecture), with the same approaches as those described above for landscapes.
A good portrait lens has its own requirements forged through time and common sense, specifically: a sizeable focal distance to shoot without distortions, soft tonal shifts, low contrast, primary element accenting (eyes, eyelashes, lips, hair), and concealment of defects (skin wrinkles, folds, defects).
When it comes to this approach, modern super sharp and contrasted lenses with maximum aberration correction suffer a fiasco of sorts. Their imagery generally just doesn’t fit this genre.
The following are considered perfectly normal and welcome aberrations for portrait photography (within reasonable limits, of course):
- Spherical aberration. Gives the shot soft tonal shifts. Removes skin defects.
- Astigmatism. Can create an interesting image in non-sharp zones.
- Curvature of the field of the image. Accents the primary subject of the photo, leaving irrelevant regions in a haze of lacking sharpness.
However, these aberrations aren’t welcome in portrait photography:
Pic. 5. Soft portrait with intense aberrations.
The best portrait lenses around have some residual aberrations implemented in them on purpose (especially spherical lenses). Other lenses, for example, the Canon 135 SoftFocus, allow you to manage the soft effect as needed (in other words, allowing you to control aberration intensity).
The classic Petzval lens remained the standard for portrait lenses for a long time despite its intense spherical aberration and curvature of field. Many photographers still consider its design ideal for portrait photography.
Of course, aside from residual aberrations, a portrait lens has a number of other requirements as well. You can find out more about them in «What is a portrait lens?».
Object Photography, Still Life, Fragments
Aberrations are generally undesirable for commercial object photography. This makes sense when you consider that when it comes to commercial small object photography, large scale object photography (i.e. furniture), and so forth, there are a number of important requirements to consider:
1. Relaying texture.
2. Relaying correct geometry.
3. High resolution and sharpness throughout the entire shot.
Thus, the higher the lens’ resolution and microcontrast, and the less its residual aberrations, the better suited the lens is for such shots. Modern professional series autofocus lenses with fixed focal range are typically quite a solid choice for the goal at hand.
Pic. 6. Furniture shot. Can be achieved by means of lenses with optimally corrected aberrations and 8-11 apertures.
However, artistic still life is a whole other deal. Such an artistic genre welcomes lenses with intense or even entirely uncorrected aberrations (i.e. monocles). These lenses can produce unmatched artistic imagery and very specific moods.
Pic. 7. Still life. Intense aberrations via a 1.2 aperture.
Genre Photography, Report Photography
Report photography generally sees the use of lenses with corrected aberrations, but report lenses have a number of other vital factors to them, including autofocus and performance speed, focal distance range for swift cropping, dust and moisture protection, etc.
Yet since report and genre photography both value the subject matter and its optimal representation most, the most important aspect is for residual aberrations not to interfere with said goal.
Wedding photography is essentially a volatile mix of report shooting and portrait photography. Effectively combining these two genres requires at least two lenses, preferably on two separate cameras, offering quick autofocus zooming for report subject matters and a fixed portrait lens with good lens speed for portraits.
Pic. 8. With a bit of dexterity you can achieve dynamic subject matter portrayals even with manual, high lens speed portrait lenses, but the challenge is considerable.
Special approaches for fields like science, medicine, cartography, and so forth typically utilize lenses with maximum aberration correction. The “why” should be obvious.
I think it’s about time to see what sorts of conclusions we can make from all this.
► In terms of aberrations and their effects, lens selection should be approached differently depending on genre and even depending on the specific task at hand. There’s no such thing as a perfect lens that works for every approach and every task. The golden rule is: there’s a time and a place for everything.
► Craftsmen more often than not prefer lenses with corrected aberrations. Meanwhile, artists pick and choose depending on personal preference.
► A properly selected lens is just a tool, which can indeed substantially improve your shots, but won’t do the core of the work for you, that being the subject matter, the main idea, the lighting, the visual portrayal, and the composition.
► The best way to find lenses that fit you is the same as finding genres that you work best with: by trying, comparing and selecting. Note that this doesn’t necessarily require the constant purchase of new optics. You can always borrow a lens from an acquaintance, or even simply look through a large number of specific photos done by means of a specific lens.
► When it comes to artistic photography (whether it’s a craftsman or an artist doing it), aberrations are far from evil. Instead, they serve as one of many methods for amplifying your shot’s expression. Just remember: everything in moderation! ;)
© 2011 Sergei Borodin. Pictures by author.