What is the difference

Looking at purchasing a sigma macro lens.

On ebay i have noticed the 105mm avaialble as EX, DG or both EX and DG.

What is the difference - also given the choice which is the better buy?

Thanks

This is from Sigma's site

LENS TECHNOLOGY

ASP (Aspherical Lens)
The aspherical lens complex allows freedom of design, improved performance, a reduced number of component lenses and a compact size.

APO (APO Lens)
In order to attain the highest quality images, the APO lens has been made using special low-dispersion (SLD) glass and is designed to minimize color aberration.

OS (Optical Stabilizer) Function
This function utilizes a built-in mechanism that compensates for camera shake. It dramatically expands photographic possibilities by alleviating camera movement when shooting by hand held camera.

HSM (Hyper-Sonic Motor)
This lens uses a motor driven by ultrasonic waves to provide a quiet, highspeed AF.

RF (Rear Focus)
This lens is equipped with a system that moves the rear lens group for highspeed , silent focusing.

IF (Inner Focus)
To ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length.

Conv (APO Teleconverter EX)
This lens can be used with the APO Teleconverter EX. It can increase the focal length and will interface with the camera's AE (automatic exposure) function.

EX (EX Lens)
The exterior of this lens is EX-finished to denote the superior build and optical quality, and to enhance its appearance.


DG (DG Lens)
These are large-aperture lenses with wide angles and short minimum focusing distances. With an abundance of peripheral illumination, they are ideal lenses for Digital SLR Cameras whilst retaining suitability for traditional 35mm SLRs.


DC (DC Lens)
These are special lenses designed so that the image circle matches the smaller size of the image sensor of most digital SLR cameras. Their specialized design gives these lenses the ideal properties for digital cameras, the compact and lightweight construction is an added bonus ! including compact and lightweight construction.

Much appreciated. Thanks very much.

How much is the lens? New or used? Usually Canon's 100mm macro, a superior lens, is about the same cost as Sigma's macro.

jr_senator wrote in post #4843469
How much is the lens? New or used? Usually Canon's 100mm macro, a superior lens, is about the same cost as Sigma's macro.

The Sigma 105 was judged superior to the Canon 100 in one magazine review I read last year. Having seen shots taken with both I would rate them at least equal. Sigma make very good macro lenses.

Mike Bell wrote in post #4843510
The Sigma 105 was judged superior to the Canon 100 in one magazine review I read last year. Having seen shots taken with both I would rate them at least equal. Sigma make very good macro lenses.

I won't argue optic quality. My understanding from reading numerous reviews and comments from fellow photographers is that IQ is equal. There are other reasons I would suggest Canon's 100mm macro over Sigms's 105mm macro. The Canon lens has internal focusing and therefore does not extend it's overall length like Sigma's does. If one is really, really close to the subject or something near the subject this may be a problem. Canon's AF (USM) is faster, quietter and more accurate more often than Sigma's. And the Canon has full time manual focus over ride, no 'push-pull' to get into and out of manual focus like the Sigma. Being that the Sigma is 'backward engineered' (like all third party lenses) there is some non-compatibility risk down the road with newer cameras. There is more such as the secondary diaphragm of the Canon. If one were deciding between Nikon's 105mm macro, which is twice the cost of the Sigma I certainly could understand. But with the cost of the Canon being so close to that of the Sigma I can't see any reason to get the Sigma.

Oh Jr.

If one wants internal focusing and full time manual focusing, The sigma 150mm 2.8 is the way to go. Heck by the time you add the hood and tripod collar for the Canon the Sigma is cheaper.

CountryBoy wrote in post #4844977
Oh Jr.

If one wants internal focusing and full time manual focusing, The sigma 150mm 2.8 is the way to go. Heck by the time you add the hood and tripod collar for the Canon the Sigma is cheaper.

So? What is the point? The OP brought up a certain price level and focal length level, the 150mm is twice the price. About the tripod coller, Sigma's 100mm macro dosen't come with one either. I have the tripod coller for mine and have never felt the need to use it, I could had just saved the expense. And the hood, which can be had for just over $20 is certainly not taking the Canon lens out of the OP's price range. It's certainly more than worth the additional $20 something dollars for all the advantages of the Canon over the Sigma. If we start to bring in different focal lengths and price levels than what the OP brought up the thread will no longer be about what the OP started.

Jr you brought up the Canon , I didn't . The OP ask about the Sigma, you provide an alternative, and I did in return.

CountryBoy wrote in post #4845075
...and I did in return.

But it's not even close to the subject.

jr_senator wrote in post #4845101
But it's not even close to the subject.

But at least I had the right brand .

To the OP- The Sigma 105mm macro is both. It's a 105mm 2.8 EX DG Macro .
It's also a very nice lens.

Much appreciated to both of you for your comments. The sigma seems to be about £200 whereas the canon is about £250. Thanks for the advice again.

By the way, for much macro photography, I bet eventually you'll find yourself turning off AF and manually focusing anyway.