The Problem with Modern Optics
This post is part of my series on lenses. For the full stories and side-by-side comparisons, go here.
When I wrote about the right kind of lenses at the beginning of this year, I laid out clear indications of characteristics people should not be buying for most photographical practices. I then wish to talk about modern lenses.
Recap (with lens diagram)
Based on our “right” gear manifesto, lenses shouldn’t be (or aim to be):
- Sharp: all lenses today are SHARP. Most modern lenses emphasize sharpness in the edges and corners where NOTHING INTERESTING IS TRULY HAPPENING (most of the time).
- Corrected at max aperture: It is a modern belief that you are supposed to get perfect corner to corner resolution at the maximum aperture of the lens. WRONG.
- Amazing at bokeh: Achieving blurred circles of confusion in your shot is as impressive as your ability to afford the lens.
- Unidimensional: And there you have it, the result of 1-2-3 turns your lenses into a specialized lens for extreme low-light photography and nothing else, thanks to the addition of up to double the glass element count in the barrel.
The Outdated Quest for Speed led to the Quest for Resolution
Up until recently, camera sensors couldn’t achieve usable image quality above ISO 1600. Fast lenses were then great options to freeze motion in low ambient light but they were not well corrected. Fast forward a few years later, many camera sensors have reached or crossed the useable ISO limit of 6400. This increase in sensitivity gain would allow lenses to be used at smaller aperture rather than at their native to correct for chromatic aberrations. Yet the birth of the Zeiss OTUS and Sigma ART prime lens series in late 2012/early 2013 encouraged the idea of a massive highly corrected fast aperture prime lens described as optics with “no-compromise”. This was wildly accepted by photography gear critics and a community of image resolution seekers, yet the results of such a thing are quite far from versatile.
The Wrong Message
Even today, the lens review industry considers “high performance optics” to possess properties located well below the high-aperture and optical correction by glass element line of the diagram. This, of course, educates the consumer to seek “optical correction” in order to fully enjoy the value of his high-resolution camera. The message is usually transmitted through:
- 100% crops of each areas of the frame, emphasizing corner and edge correction for edge to edge resolution.
- 100% crops of the blur circles of confusion (the bokeh)
- Numerical “sharpness” values based on how many “lines of resolution” is measured
- Persecuting vignetting and distortion as defects of the lens
Often referred as a “cold and clinical lens”, such an ideal lens has quite limited abilities, especially if the user wishes to shoot other things aside from high-contrast for "ultra-lowlight or ultra-thin-dof handheld photography”: a lens in the red zone, below the "line of realism" wouldn’t perform as well for spaces, still or moving life capture compared to a another with much less correction and much more 3d as well as tonality. These high-speed lenses not only cost more since their require more corrective glass, but the micro-contrast treatment would need to be applied at abuse.
Modern prime lenses fall below what’s natural
If we look at those approximative diagrams per brand/system, we notice the gravity of the obsession for optical correction.
By either cheapening glass quality or relying too much on micro-contrast treatment (ineffective against too many glass elements), modern lenses are barely able reproduce the imperfect life despite heavy post-processing by the user. Of course, they were built to photograph in situations where the human eye cannot reach or recognize. Their rendering are often described as “digital” or “flat”. You can rarely cheat the diagram (all of this applies to lenses 35mm and up, wide angles operate on another criteria).
The example below once again demonstrates the loss of color and micro-contrast jumping back and forth between old Nikkor and Sigma.
Older prime lenses don’t just have "character", they simply record life
Many people shoot film because they believe in a “there-is-something”, “true”, “organic” and “genuine” reproduction of life with “interesting” or “unique” character. Simply put, those low-element count multicoated “film” lenses were built for maximum physical transparency, 3d rendering and rich tonality. These also possess such life recording abilities when used on a digital camera. If we look at most lenses made before the surge of high-element count primes, many of them share common design and rendering properties.
Lenses used by professionals then, lenses used by the professionals in the know, now.
Solution for modern lenses: improve glass and coating quality on old designs
The late 9 elements Zeiss ZF.2 35mm f2 Distagon is very close to striking the absolute balance of maxed-out quality glass and coating while flirting with the limits of optical correction before losing the ability to reproduce life. A lens of such versatility would definitely produce more life-like images than the digitally flat ones that the review world is advocating. Had manufacturers revisited old optics such a philosophy, we would witness the true evolution of life-like image quality. Sadly, the solution will require way too many changes in the industry.
A Call for Change
If people are listening right now and realizing the gravity of the situation, here are some suggested changes in photography gear talk:
- A clear indication of lens application specialty based on where the lens is situated within the lens intention diagram.
- If a lens is made for extreme low-light and thin-dof shooting, don't suggest using it on anything else!
- An honest discussion on the lens’ renditional abilities based on how it measures on the 3 opposing properties of the lens diagram.
- A better and simplified (5th grade level vocabulary) education of lens usage in relation to modern sensors of high gain and advanced SNR firmware algorithms (i.e. encouraging correction by aperture instead of correction by glass element)
- A strict demand for true improvement to modern optics by rejuvenating old designs with improved high quality glass and coating.
- A better and simplified education of lens design (what plastic elements do vs. full glass vs ED, etc…) to justify eminent increased pricing.
- A more critical and educated demography of users.
New Lens Acquisition Behaviour
Simply buy the lens design that is made closest to your desired photography style. There’s a high probability that most of the lenses made for capturing life are affordable, out there and deemed “obsolete” by today’s review standards. Although these are increasingly hard to find in good shape, I wish you good hunting!