IS, VC, DG, DX, Canon, Sigma, Tamron, EF-S, L, USM, XR, LD, IF, DI, DI-ii – Making Sense of all the different lens terminology.

Just about every camera lens manufacturer has the same features in their lenses. They of course all use different terms to describe those features. Go figure. So it’s up to you to make sure the lens will fit your body, full frame, or not full frame. That said, all lenses are not created equally. In fact, just within Canon – there are three 70-200mm lenses and they are all different. [hr]

Canon Lenses

• EF: Electronic Focus
  • The EF lenses will work on Full Frame Cameras, the EF-S lenses will not.
• EF-S: Short-Back Electronic Focus
  • All this means is that the lenses will not work on Full Frame Cameras like the 5D Mark II or Mark III
• TS: Tilt-Shift , TS-E: Tilt-Shift, Electronic aperture control
  • Tilt shift is great for keeping vertical lines straight, like in architecture photography – or you may have seen TS lenses used for achieve the miniature effect.
• IS: Image Stabilization
  • A huge plus! Not to be underestimated, saving up to two stops of light. Assuming you don’t have a fast moving target IS can be a life-saver. Often worth the price difference.
• USM: Ultrasonic Motor
  • Really good and quiet focus mechanism. You can usually just grab the focus ring and manually focus without physically switching the focus switch.
• STM:
  • Inferior auto-focus. Means stepping-motor. Not as quiet. Not as fast. Cannot grab focus ring and manually focus while in AF mode.
• DO: Diffractive Optics –
  • Irrelevant to most of us. We don’t care. Special pieces of glass to control aberration. We don’t care, we just want a good performing lens.
• L: Luxury series
  • It’s like the L in Lexus, it just means it’s better than the standard Toyota and you will pay for it.
• Macro: close focusing
  • This is what you need to look for if you want to take pictures of the hair on a honey-bee.
  • MP-E: Macro-Photography, Electronic aperture control
• Softfocus ability to use soft focusing for smooth dreamy look
  • Garbage. Light well, use shallow depth of field – there are better ways.

Sigma Lenses

• HSM: Hypersonic Motor
  
  • Like Canon, this is good and quiet focus mechanism.
• ASP: Aspherical lens element
  • Glass trickery, but like DO, we don’t really care as long as the lens performs. Look out for things like chromatic abberation or vignetting when you get into ASP.
• APO: Aphochromatic (low-dispersion) lens element
  • Again, glass wizardry and we don’t truly care as long as the lens does well. These kinds of terms and acronyms are like on car brands. The z37 i classC. Ya know. It means there are features, but at the end of the day, we just want a good product.
• OS: Optical Stabilizer
  • OS is like IS for Canon, a huge bonus. Won’t help much for sports or action because you won’t have any need to shoot at 1/20 second.
• IF: Inner focusing
  • This is a good thing, it means that there are fewer external moving parts. It likely means better weather sealing. Less places for a single grain of sand to wedge itself.
• EX: Professional lens body finishing and construction
  • Means they are pretty. And probably not made of cheap plastic.
• DG: I don’t know what it stands for.
  • But I know it means it supports full-frame cameras 
• DC: I don’t know what this stands for either.
  • But I do know that it will not work on full frame cameras. These are like Canon EF-S lenses.
• DN: For mirrorless cameras
  • Scoff.
• Macro: same as above.

Tamron Lenses

More of the same, but all different – Tamron has loads of terms. They use all kinds of glass wizardry in their products.

• XR: Extra Refractive Index Glass
  • This translates into lighter and more compact lenses. Again, we just care about performance.
• LD: Low Dispersion
  • This is to reduce and help with chromatic aberration. They can put these terms all over the boxes, but we have to look at the focus charts to see the effect.
• XLD: Extra Low Dispersion
  • Same as above, obviously, but apparently they try even harder!
• ASL: Aspherical
  • Glass wizardry to help plane convergence. Who  knows…
• LAH: LD + ASL hybrid lens element
  • I have no idea.
• AD: Anomalous Dispersion
  • Same effect as LD and XLD, but now we have AD. Seriously?
• ADH: AD + ASL hybrid lens element
  • More.
• HID: High Index, High Dispersion Glass
  • And more chromatic aberration fighting. Sounds like Tamron is a superhero to protect against red/green/yellow spilling.
• Real Features to look for-
  • VC: Vibration Compensation
    • Like IS from Canon or OS from Sigma. A good thing to have.
  • USD: Ultra Silent Drive
    • Like USM, but they want to call it something unique.
  • SP: Super Performance
    • This is what Tamron would consider their L-Series glass, it’s the professional grade stuff.
  • IF: Internal Focusing System
    • Already explained above – keeps the moving bits inside and away from dust and debris.
  • Di:
    • What you want if you have a full-frame camera. Avoid Di-II
  • Di-II:
    • Will not Work on Full Frame camera.
  • ZL: Zoom Lock
    • Does what it says. Keeps barrel from moving.
  • A/M: Auto-focus/Manual-focus Switch Mechanism
    • Just about every AF lens has this.
  • FEC: Filter Effect Control
    • Keeps your lens filters in the correct orientation.