Tamron is famous for coming up with a very long and confusing product name. Maybe coming up with a product name is not their strength, but they can certainly do better with product naming.

As a buyer, you need to understand their acronyms to understand what Tamron is offering. When I bought my first Tamron lens, I was not paying attention to those acronym and just chose one that has the longest name :D.

It ended up costing me a lot of money but I never really use the feature, so that I learned a lesson.

So, to make my life easier, I did some research and compiled this quick and easy to understand guide to decode Tamron’s confusing acronym.

Hopefully this guide will make your life easier as I’ve tried to decode their technical terms and make it as non-technical as possible for you to read.

Make sure you refer to this guide to really understand what features you’re getting before purchasing any Tamron lens.

OK, Get ready for the list…

Acronym Descriptions Features & Benefits
AF AutoFocus Allows the lens to automatically focus on your subject.
SP Super Peformance Tamron’s code for “expensive” lens. You’ll get sharper glass with low chromatic aberration (purple halo around certain subject’s edge). However, expect to pay more.
Di Digital Tamron lens with optics designed specifically for digital sensors. Can be used for full frame, smaller sensor or film cameras.
Di-II Digital-II Tamron lens made for Cropped Sensor Digital SLR (less than 24x16mm). You should not use this for full frame or film cameras.
IF Internal Focusing Allows lens to focus without changing size or dimension. Also make the lens more compact and lightweight as well as having faster focus and closer focusing distance.
ASL Aspherical Minimizing lens aberration and distortion. Also make the lens more compact and lightweight due to less number of elements.
LD Low Dispersion Minimizing sharpness fall-off due to chromatic aberration in close focusing at the telephoto end.
AD Anomalous Dispersion Reducing chromatic aberration for telephoto lenses and lateral chromatic aberrations for wide angle lens.
XR Extra Refractive Index Glass Making the lens shorter and more compact.
BIM Built-In Motor Allows the lens to autofocus in camera without built in motors such as Nikon D40, D60 or D3000.
VC Vibration Compensation Tamron’s Image stabilization method. Will reduce image blurriness due to unstable handholding. Also minimize the shake in your viewfinder, giving you clearer viewfinder when taking pictures, a VERY handy feature.
HID High Index Dispersion Minimizing on axis and lateral chromatic aberration.
ZL Zoom Lock Prevents undesired zoom creep (lens sliding out on its own when tilted downwards) by utilizing a lock mechanism.
AF/MF Auto/Manual Focus Switch Allows you to switch quickly between Auto and Manual focus, a very handy features for macro lenses.

Good, remember all of them?

Just kidding.

I told you, Tamron is VERY good at creating long and confusing acronym.

If you notice closely, not all of them are important. Some of them are just pure marketing fluff (like SP).

So, which ones are the most important? For me personally, the acronyms that I will look at before buying any Tamron lens are:

AF and IF – I’ll make sure the lens has autofocus function and internal focusing. This will allow me to autofocus my lens without changing my lens’ dimension. (i.e. the lens will not get longer or shorter as it autofocus).

Di vs. Di-II – This is very important. You don’t want to use Di-II lens if you’re using full frame camera (such as Nikon D3 or Canon 5D). Di lenses are fine for both full frame and small sensor camera.

BIM – If you’re using a Nikon camera without a built in motor (D40, D60, D3000, etc.) then you’d want to make sure the lens has this feature. Otherwise your lens will not autofocus with your camera.

VC – Vibration Compensation is a nice feature to have, but I can live without it.

There you have it. Now you should understand better about Tamron lens and I hope this guide has been a helpful one. I will see you in the next articles or review.


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