If you've ever shopped for a lens and seen the phrase "35mm equivalent," you know photography jargon can be confusing. This term is the key to understanding how different cameras see the world. Here is exactly what it means and how to use it to choose the right lens.
Found a deal on a new camera or lens that seems too good to be true? It might be gray market. So what does that mean? Is it a bad thing or just a good deal? And what are the risks in buying gray market gear?
Laowa lenss use various codes in their names to denote compatibility or particular features. Here's how to make sense of them.
A prime lens has no zoom, just a fixed focal length like 50mm or 85mm. That simplicity often means faster apertures and sharper images, here's why that matters and which prime lenses are worth trying.
Rokinon lenses offer incredible bang-for-your-buck, but their naming convention is a confusing soup of "Cine DSX," "AS," and "UMC." Are Rokinon and Samyang really the same thing? Does the V-AF line actually have autofocus for video? We break down every cryptic code on the barrel to help you buy the right glass for your Sony, Canon, or Nikon camera — including the modular Remaster Slim system.
If you've ever seen mention of the Sunny 16 Rule and wondered what it means, here's an explanation.
Get to grips with fast lenses--what they are, how they work and why they're so popular among photographers. Learn what defines a fast lens, the benefits of shooting with one, and good lenses to start with. Plus, discover some lens gotchas to watch out for.
Sony uses a specific set of codes to distinguish its lenses, from the entry-level "E" series to the top-tier "G Master" glass. As a relative newcomer compared to Canon or Nikon, Sony's list is shorter, but the rapid evolution of their autofocus motors (from SSM to XD) can still be confusing. Here is the complete breakdown.
Pentax users pride themselves on backward compatibility — you can mount a 1975 lens on a 2024 camera. But the alphabet soup of lens codes (DA, FA, PLM, DC) tells a different story. Some new lenses won't work on old bodies, and some old lenses need special settings to work on new bodies. Here's a breakdown of the Pentax code language.
Before threaded screw-on filters, lenses used a three-piece slip-on system sized by "series" number. Here's how Series 7, 8 and 9 filters actually attach, and why you'll still meet the term on vintage manual-focus lenses.
Scanning decades of old negatives often means staring at cryptic numbers like "5053" or "GA" on the film strip. I compiled this reference guide to help you (and me!) cross-reference those edge codes with the actual film types to make your archiving and editing easier.
There is no name more distinguished in optics than Zeiss, but their naming convention is anything but intuitive. Unlike other brands that use tech-jargon, Zeiss names lenses after birds and century-old optical formulas. From the autofocus Batis to the manual-focus Milvus and the legendary T* coating, here is a plain-English guide to understanding exactly what you’re buying when you see that famous blue badge.
Tokina lenses are legendary for their "built-like-a-tank" construction, but their naming system has undergone a massive overhaul recently. If you’re confused by the jump from "AT-X" to "atx-i" or "opera," you aren’t alone. Here is the definitive guide to every code Tokina uses, including their unique Focus Clutch mechanism and their 2026 mirrorless lineup.
Tamron Di, Di II, Di III, VXD, SP — what do they actually mean on a lens barrel? This guide breaks down every current and legacy Tamron code, from sensor compatibility to autofocus motors and glass coatings.
Sigma lens names can be a mouthful of acronyms. Once you know how to read them, however, they are a powerful shorthand for identifying whether a lens is built for full-frame or crop sensors, DSLRs or mirrorless cameras. This guide demystifies the alphabet soup so you can quickly categorize any lens in their massive lineup.
As a relative newcomer to the modern mirrorless game, Fujifilm hasn’t accumulated the decades of confusing acronyms that Canon or Nikon have. But their naming convention is precise, and knowing how to read it will tell you exactly what you are buying — and whether it has that all-important aperture ring.
VR? ED? S-Line? Plena? Nikon lens names are a alphabet soup of confusing abbreviations. This guide decodes them all — from the latest Z-mount tech to vintage manual focus terms — so you know exactly what you're buying.
Like most lens manufacturers, Canon uses codes in their lens names to identify key features and technologies of the lens. They might look like a look like a random jumble of letters, but they are actually a precise formula. Once you know how to read them, you can instantly tell if a lens will fit your camera, how fast it will focus, and whether it is weather-sealed.
Many digital cameras these days come with impressive ISO ranges. But if you look at the specs more closely, they'll often break it down into native ISO and extended ISO. Here's an explanation of what that means.
That small vibration and click every time a DSLR's mirror flips up is called mirror slap — and mirror lock up is the setting built to stop it. Here's what mirror lockup (MLU) actually does, how it differs for shooting versus sensor cleaning, and when it's worth using.
Fisheye lenses pack a dramatic, distorted view into the frame — great for tight interiors and immersive action shots, terrible for portraits and architecture. Here's what to know before you shoot with one, including the two main types and what to avoid.
That odd little circle-and-line symbol stamped on the top of many cameras isn't decoration, it marks the exact location of the sensor or film plane inside, and it can matter more than you'd think for macro work and panoramas.
That small rectangular mount on top of your camera does more than hold a flash in place — it sends an electrical signal between camera and accessory. Here's how a hot shoe works, how it differs from a cold shoe, and whether you need a cover.
Off-camera lighting is the secret to professional-tier photography. Whether you prefer bite-sized projects or deep-dive masterclasses, here are the best online courses to help you master your flashes and strobes.
Whether you're looking to brush up, dive deeper, or learn a new photographic skill, here's a roundup of some of the best online classes and courses for photographers.
Why is the jump from f/5.6 to f/8 a full stop, but f/1.4 to f/1.8 is only two-thirds? The math behind lens apertures is famously counterintuitive, but mastering it is the key to perfect exposure. We’ve built a custom, mobile-friendly F-Stop Calculator to help you instantly solve for ND filter offsets (including Big and Super Stoppers) and compare increments across the entire range — from f/0.95 "Noct" glass to f/32. Use this interactive tool and charts to take the guesswork out of your next shoot.
We expect light to come in the front of the camera. Shooting with the lens cap on doesn't tend to work so well. But we don't always expect it to come in the back. Here's a real-world example of light leak through the viewfinder.
Dust bunnies, which leave ugly dark spots and marks on your images, are one of the annoyances of digital photography. If you're changing lenses on the go there are some tricks to minimize them.
My name is David Coleman, and this is my site. I take photos for a living. Seven continents. Dozens of countries. Up mountains. Underwater. And a bunch of places in between. I'm based in Washington, D.C.
This site is where I post practical photography help, tips, and troubleshooting.
All posts and reviews on this site are written by me. And I only review gear with which I have personal hands-on experience. By a photographer, for photographers. More about me.
© 2009-2026 David Coleman | Have Camera Will Travel LLC
Photos by David Coleman. Please contact me for licensing images. Images are registered with the U.S. Copyright Office.
Have Camera Will Travel LLC | 901 N Glebe Rd, Arlington, VA 22203 | +1.703.942.9245
