whats the difference sigma APO & DG?

[Trev Rich]

I have often wondered this.. but whats the difference between the Sigma 70-300mm DG lens.. and the APO version?

 

[AliB]

APO stands for apochromatic Basically lenses are actually a series of elements. Those elements are made of glass and any piece of either convex or concave glass will transmit differing wavelengths of light differently some may bend the red a little more or the blue end of the spectrum. This is called chromatic aberration. Lenses with the APO designation are coated to try to resolve this anomaly.

 

[yourapocalypse]

APO means 'apochromatic', something to do with making the images sharper. Basically APO = better.

Edit: Too slow

 

[Trev Rich]

Hmmm... i currently use the DG but the images just don't seem sharp enough..
Might be worth buying the APO then selling the DG...

 

[andrewc]

APO version is better. I had a DG version - cheap as chips and tried hard, but it was quite soft at the long end. Sold it easily enough though. Bought a Sigma 100-300 f4 instead.

 

[Trev Rich]

Well the APO is on order so will getting rid of the DG soon.
Before I do though.. I will have to do a quick comparison thread.

 

[Migs]

Check this out!!!!! It will give you all the abbriviations needed

http://www.sigma-imaging-uk.com/support/abbriviations2.htm

 

[foodpoison]

You won't find the APO much sharper though.
Its at it's sharpest at 70mm.

 

[Slapo]

This is a bit more chatty description:
http://www.sigmaphoto.com/lenses/lenses.asp