Things You Didn’t Know About Camera Lenses: Understanding Camera Lenses for Video Production
If you’ve ever wondered why some camera lenses cost a few hundred dollars while others are priced like a small car, you’re not alone. The truth is, lenses are more than just pieces of glass, they’re precision instruments built to exacting standards. Every detail, from how light bends through the glass to the size of the image circle, determines the quality of your final image.
Now, let’s be clear: this isn’t a “beginner’s guide.” If you’re brand new and just trying to figure out what focal length means or how aperture works, this might not be the read for you. But here’s the thing, if you’re curious enough to be here, you can keep up. And chances are, by the end, you’ll understand lenses in a way that even many working professionals don’t.
In this guide, we’ll go beyond the basics. We’re going to break down the technical standards that shape modern lenses: medium format vs full frame, T-stop vs F-stop, line pairs per millimeter, refraction, image circles, and more. By the time you’re finished, you’ll know exactly why camera lenses are held to such high standards, and why that matters so much for video production.
The Foundation of Camera Lenses
Why Lens Standards Exist
Camera lenses have to do one thing exceptionally well: bend light in a predictable, repeatable way. But because cameras come in different formats and because filmmakers need consistency across shots, lens manufacturers have established standards. These standards make it possible for professionals to match exposure, color, and sharpness no matter what lens they’re using.
Key Technical Terms to Know
Before diving deeper, let’s get familiar with some of the terms you’ll see throughout this article:
Aperture: The adjustable opening in a lens that controls how much light enters.
F-Stop: A mathematical ratio of focal length to aperture diameter.
T-Stop: A measurement of the actual light transmission reaching the sensor.
Image Circle: The circular area of light projected by a lens that must fully cover the camera’s sensor.
Refraction: The bending of light as it passes through glass.
Line Pairs Per Millimeter (LPPM): A way to measure the resolution and sharpness of a lens.
Medium Format vs Full Frame: The Battle of Formats
What is Medium Format?
Medium format cameras use larger sensors than full frame, typically around 44mm × 33mm or more. This requires lenses with bigger image circles to cover the sensor. The result is extraordinary detail, creamy depth of field, and smoother tonal transitions. That’s why medium format is favored in high-end fashion, fine art, and some forms of cinematography.
What is Full Frame?
Full frame cameras use sensors based on the traditional 35mm film format (36mm × 24mm). This is the gold standard for both professional photography and cinema cameras. Full frame offers versatility: excellent low-light performance, a balance between depth of field and field of view, and compatibility with a massive range of lenses.
Other Formats: APS-C, Super 35, and More
Not every camera is medium format or full frame. Many professionals and hobbyists use APS-C sensors, which are smaller than full frame and common in DSLR and mirrorless systems. Super 35 is another key format, especially in cinema, with a sensor size smaller than full frame but optimized for film-like depth of field. Even smaller formats exist — Micro Four Thirds, 1-inch sensors, and beyond. Each of these formats requires lenses with a matching image circle, and each brings its own balance of cost, portability, and aesthetic.
How Format Affects Image Quality
Medium format: Dreamy look, massive resolution.
Full frame: All-around balance and flexibility.
APS-C / Super 35: Affordable, cinematic depth of field.
Micro Four Thirds: Compact and lightweight setups.
Video Production Considerations
For video production, full frame has become the most common choice because it strikes the perfect balance between quality and practicality. Medium format delivers unmatched visual richness, but it comes with higher costs and heavier gear. APS-C and Super 35 still play a huge role in cinema, especially when paired with lenses designed specifically for them.
T-Stop vs F-Stop: Why Filmmakers Care
F-Stop Basics
F-stops are the most common way to describe aperture. It’s a ratio: focal length divided by aperture diameter. An f/2.8 lens allows in more light than an f/4 lens, but it doesn’t account for light lost inside the lens.
What is a T-Stop?
T-stops (Transmission Stops) measure the actual light reaching the sensor. For example, a lens marked as T2.9 might have an f/2.8 aperture, but coatings and glass reduce light transmission slightly.
Why T-Stops Matter in Video Production
In still photography, a tiny difference in exposure is no big deal. But in video production, consistency is king. When cutting between multiple lenses in the same scene, you need identical exposure levels. That’s why cinema lenses are rated in T-stops — filmmakers can swap between lenses and maintain perfectly matched brightness.
Lens Resolution and Line Pairs per Millimeter
Defining Resolution in Lenses
Resolution isn’t just about megapixels. Lenses are rated in terms of line pairs per millimeter (LPPM), a measurement of how many black-and-white line pairs a lens can resolve on a sensor.
Why Resolution Standards Exist
This standard helps cinematographers know whether a lens can keep up with modern sensors. An 8K cinema camera is wasted on a lens that can’t resolve fine details.
Practical Applications in Video Production
For video production, higher resolution lenses ensure that footage looks sharp even after cropping, VFX, or scaling. It also means your lens won’t become the weak link when upgrading to 6K or 8K workflows.
Refraction and the Physics of Glass
How Refraction Shapes Images
Every lens works by bending (refracting) light. But the more elements a lens has, the more opportunities there are for distortions like chromatic aberration, color fringing, or loss of sharpness.
Lens Coatings and Correction
Modern lenses use advanced coatings to minimize reflections, flare, and ghosting. Coatings also enhance contrast and color accuracy, which are crucial for professional production.
Real-World Impact in Video Production
Refraction isn’t always a problem. In fact, some filmmakers deliberately use lenses with imperfect refraction for artistic flares and vintage looks. Think of J.J. Abrams’ signature lens flares — that’s refraction being used as a stylistic choice.
The Image Circle: Covering the Sensor
What is Image Circle?
The image circle is the round projection of light a lens throws onto the sensor. To fully capture an image without vignetting, the circle must cover the sensor size.
Why It Matters
A lens designed for APS-C may not cover a full-frame sensor. If you try, you’ll see dark corners or heavy vignetting. That’s the image circle falling short.
Video Production Relevance
In video production, mismatching lenses and formats can ruin footage. Using a Super 35 lens on a full-frame camera without cropping mode can lead to unusable edges. On the flip side, cinema DPs sometimes use this effect deliberately for creative vignettes.
Cinema vs Photography Lenses: Standards Compared
Build Quality
Cinema lenses are built for durability, with metal housings, geared focus rings, and smoother mechanics.
Consistency Across Sets
A full set of cinema lenses will all share the same gear placement, size, and color reproduction. This saves massive time on set.
Case Study in Video Production
Netflix and other streaming platforms often require productions to use cinema-grade lenses on approved cameras. That’s because consistency, resolution, and light transmission matter at scale.
Choosing the Right Lens for Video Production
Matching Lens to Storytelling
Medium format: Great for fashion films, high-end commercials, dreamlike aesthetics.
Full frame: Perfect balance for narrative films, branded content, and versatility.
Super 35 / APS-C: Budget-friendly cinematic look, widely supported.
Practical Budget Considerations
For most businesses and creators, buying a full cinema lens set isn’t practical. That’s why renting lenses for specific projects is a common solution.
FAQs — Understanding Camera Lenses
What’s the difference between T-stop and F-stop?
F-stop is a calculation of aperture size; T-stop measures actual transmitted light.
Why do filmmakers use T-stops instead of F-stops?
For exposure consistency across different lenses during a shoot.
Does line pairs per millimeter matter for video production?
Yes, especially for 6K/8K cinema workflows where lens resolution must match sensor resolution.
How does image circle affect my footage?
If the circle doesn’t cover your sensor, you’ll see vignetting or dark edges.
Is medium format better than full frame for video?
Not necessarily. Medium format is beautiful but impractical for many productions. Full frame offers the best mix of quality and usability.
Conclusion
When you think about it, camera lenses aren’t just tools — they’re engineering marvels. From the way they bend light to the precision of their T-stop ratings, every detail is designed to maintain professional standards. For video production, these standards are what make consistent, beautiful storytelling possible.
So next time you pick up a lens, remember: you’re holding decades of optical science in your hands — and understanding these details is the first step toward mastering your craft.
