Lens Abbreviations

[Dante King]

I am a newbie to DSLR camera and a LONG time ago was an A1 user. I have for the life of me been unable to find out what the abbreviations for the lenses. USM, L, IS (image stabilization?, and the list goes on. I did a search but alas nothing popped up. Can anyone point me in the right direction. As well a short into as to the quality differences as well would be much appreciated. Sorry if this is a stupid question! (Ducks head and runs in fear if tossed cinder blocks)

[tim]

USM = ultrasonic motor. It means the focusing is fast and quiet.
L = luxary, the best canon lenses are L lenses, they have a red stripe and some are colored white.
IS = image stabilisation. It means you can hand hold it for longer without camera shake affecting your pics.

[Belmondo]

USM = ultrasonic motor (not to be confused with unsharp masking, a sharpening technique)
L = Luxury (Canon's designation for professional lenses)
IS = you got it---Image stabilization

[EDIT]
Tim obviously types faster than I do. Do you notice a similarity in our answers?

[Scottes]

USM is Ultrasonic Motor, specific to Canon models. Sigma calls it's version HSM (high speed motor?). But note also that USM could mean UnSharp Mask, a sharpening method usually used when talking about processing images. IS is Canon's Image Stabilization, and Sigma has OS, Optical Stabilization. L stands for Luxury, and is often denoted as L around here. They're Canon's top-of-the-line lenses, though many great lenses from Canon are not L. DO is Diffractive Optics, a different way of making lenses which uses fresnel technology. LD/UD is Low/Ultralow Dispersion lenses, which (I think) helps aim the elements better for less chromatic aberration. (Someone correct me on that last one if I'm wrong as my brain is going to sleep on me....)

[Scottes]

Well, Tom beat me with his quick typing to get his post-count up, but as usual I had both more info AND more useless info than him.... :-)

[Belmondo]

Well, Tom beat me with his quick typing to get his post-count up, but as usual I had both more info AND more useless info than him.... :-)

Yeah, but you managed to turn this into two posts.

Oops, so did I. :oops:

[tim]

Tim obviously types faster than I do.

Too much caffine ;)

[cmM]

im just guessing here.... does VR stand for vibration resistance ? (I know it's a term from the darkside, just wondering)

[Dante King]

Thanks, you guys are fast. What a great forum!

Ok, more questions if you guys and gals can humor me a bit more:

What is a USM used for?

What is fresnel technology?

I have a DRebel with the kit lens and a tamron 28-300. I shoot pics of my kids and their events. what lens would be a good addition to these?

What flash would be a good addition for the DRebel?

Thanks again for your quick response and your help!

[pcasciola]

Here are a couple of other Canon ones you might come across:

EF = Electronic Focus
EF-S = Electronic Focus - Short back focus (currently 20D/300D compatible only)
DO = Diffractive optics. These lenses have a green stripe instead of the typical red stripe found on L lenses, and are much shorter and lighter than their standard refractive counterparts.

[tim]

USM is just a fast, quiet focusing motor in a lens.

For the rebel, i'd suggest the 420EX or the 550EX. The 550 has more controls on the camera, but if you install the firmware hack you can use FEC (flash exposure compensation) on the camera to make the flash brighter or less bright as you require.

[Belmondo]

Here is a description of a Fresnel lens. They were used in lighthouse lenses, but have also seen other applications. The little plastic magnifying glasses you see that are essentially flat and have concentric circles etched into one side are Fresnel lenes.


http://acept.la.asu.edu/PiN/mod/light/supp/fresnel.html

BTW, a Fresnel lens figures prominently in a new novel by Jimmy Buffet, the singer. I think the book title is something like "A Salty Piece of Land" or something like that.

[Arsonist lolol]

I'm glad you asked this Dante King, I was wondering too haha. Glad to see I'm not the only one :)

[Citizensmith]

Should probably add in
AFD (Arc Form Drive) the older focus motor generally found on kit and prime lenses. Generally indicated by a silver stripe or no coloration.
FTM for Full Time Manual Focus the occurs on Ring-USM and the Micro-USM 50 f/1.4. FTM allows you to manually touch up focus without switching out of autofocus. FTM is generally a good way of telling if you are getting the decent Ring-USM or the weaker Micro-USM. Ring allows it, Micro doesn't with the exception of the 50 f/1.4 which has a special clutch mechanism. USM is generally indicated by a gold stripe.
EF-a for the now defunct auto only, electronic zoom lenses Canon made for the EOS series.
SF only shows up on the 135mm f/2.8 Soft Focus lens.
TS-E for the manual focus Tilt Shift lenses.
MP-E for the 65mm Macro Photography lens which lacks infinity focus.
II, III, etc indicate later versions of a lens, often with incremental improvements.

That'll do for now.

[ron chappel]

sigma have some odd designations
EX is the term given to their best lenses
HSM -as explained above + hypersonic motor (a fast ,silent motor)
OS is their version of IS .It means optical stabilization
DC a lens made especially for digital (ONLY for digital croped sensors?...not sure about that one)
DF is what sigma call their kinda good idea for smooth damped manual focus feel (but it's stupidly implimented-tamron did it right)
APO -apochromatic glass elements.This helps keep all the colours of the spectrum focused equally-especially usefull for long lenses.May or may not be a better lens for having this printed on it-Canon have better stuff than this but don't print it all over their lenses

Tamron have a ton of abrieviations! I'll try doing a few,LOL

XR -extra refractive glass.This helps bend light better,making a lens shorter
Di -optomised for digital-usually with better antireflection coating on the rear element and better sharpness at the edges.But wether a particular digital camera needs these 'improvements' is another question.
LD -low dispersion glass.I THINK this is the exact opposite to XR glass .So if i have this right....XR glass bends light rays from one end of the spectrum more than the other,while LD helps bend the opposite end of the light spectrum more.APO is probably best described as a lens that is fully corrected (no matter how one goes about it)
ASP -Aspherical elements.All lenses except for asp's are sections of spheres .These are used where a spherical element introduces too many aberations.
There are three main types of asphericals:
Ground or lazer cut glass-these are the most expensive
Hybrid types where an optical plastic is moulded to a spherical glass lens .Most cheap superzooms have these ,i.e tamron,sigma
Fully moulded glass .These last ones are not the best i've read as they haven't been finely pollished.I'm not sure what the current state of tech is though

[Dante King]

Thanks again, very useful!

[nosquare2003]

im just guessing here.... does VR stand for vibration resistance ? (I know it's a term from the darkside, just wondering)

No, there's no such abbreviation in Canon's dictionary. Anyway, you've got a wrong guess (or half correct).

[tim]

I think by the "dark side" reference he was implying VR was a nikon term.

[cmM]

I think by the "dark side" reference he was implying VR was a nikon term.
Yup, that's what I was reffering to

[nosquare2003]

VR = Vibration Reduction

P.S. How to delete this message from my memory?

[Jesper]

Canon: IS = Image Stabilizer
Nikon: VR = Vibration Reduction
Sigma: OS = Optical Stabilizer (as far as I know Sigma has only one lens with OS, the 80-400)
Minolta: AS = Anti Shake

The Canon, Nikon and Sigma systems work the same: the lens contains special moveable elements and gyroscopes that counteract the shaking of your hands, so that the image stays stable. Minolta's Anti Shake is inside the camera body - the sensor is moving to counteract the shaking of your hands.

Have a look in the Canon Camera Museum (http://www.canon.com/camera-museum/index.html) and the Canon EF Lenses Home (http://www.usa.canon.com/html/eflenses/index.html). These websites contain articles that explain all the technologies and abbreviations that Canon uses.