[galelegg]

I have bought 2 Sigma 100-300mm 1:4.5-6.7 DL lenses on EBay in 2 separate transactions. At the time of buying the second lens I thought I would be buying 2 identical lenses. After comparing these 2 lenses against each other I found differences.
The first I bought we will call Lens A. Lens A has a metal mount with 5 circular gold electrical contacts, to the left of the lens 3 contacts then a wider space to 2 contacts to the right side of the lens base.
The second bought call Lens B. Lens B has black plastic (I assume) base plate that contects to the camera body with 3 circular gold electrical contacts. To the right side of the plate it has 1 circular gold contact followed by a rectangular shaped contact with outside curved then another circular gold contact. In all Lens B has 6 contacts Lens A has 5. My question is do these lenses have any different functions of performances to each other.

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Last edited by galelegg; 07-01-2015 at 10:56 PM.

[Reed]

It may be two generations of this lens, I had one with plastic mount. It was quite nice for me in it's time,very fast AF but not realy good IQ, I dunno how will it work on today's DSLR. If it fits on your camera properly-it should work, no mater of the mount version. Can you post the pictures of that lenses?

[galelegg]

Thanks for the reply Reed. Attached is a photo of the 2 lenses. Notice that the lens to the left has a different gold contact configuration than the lens to the right. Both lenses appear to perform the same although I think the one with the metal connection is better. My question is do these lenses perform differently to each other in terms of these contacts? Thanks. .

[Reed]

If you mean that copper colored plate on plastic mount, it is just the grounding/shortening pin-on the metal bayonet whole metal mount works as one No needs to worry, both lenses should work the same way.I had the DA 50 1.8 that has a standard plastic mount just like your sigma, I have switched it to metal one from broken zoom lens bayonet plate and it works perfectly.Not that i had to-the plastic one is ok, but just my curiosity had me to try it

[clawhammer]

I have the Quantray re-badge of the one on the left (your lens B) and it works just fine. Its become my poor-mans sports lens thanks to its very short focus throw ( = faster focus than the DA 50-200) and has done pretty well.

[galelegg]

Thanks for the advice. I have successfuly used this lens for photos of soccer and Australian rules football matches and I did not know why. Seems to me a very underated and underpriced lens, can be bought for under 10AUD.