Diffractive optics

[Robster]

Hi All,
Can somebody please help me out here! because the two shops I have asked cant.
The Canon 70-300mm Diffracive Optics EF Lens does this use the same quality of optics as the L lens range or does it not have UD glass for chromatic aberration.

Or are we just parting with a lot of cash for compactness and the use of this DO optic.

Thanks

Robster

[ap4a]

There's no mention of UD elements here: http://www.canon.com/camera-museum/t...report.html#t8

Nor in this review: http://www.the-digital-picture.com/R...ns-Review.aspx

[flake]

Originally Posted by Robster

Hi All,
Can somebody please help me out here! because the two shops I have asked cant.
The Canon 70-300mm Diffracive Optics EF Lens does this use the same quality of optics as the L lens range or does it not have UD glass for chromatic aberration.

Or are we just parting with a lot of cash for compactness and the use of this DO optic.

Thanks

Robster

There's more to an L lens than the glass inside it! The build quality of the DO optics is about the same as the 'gold band' lenses - perfectly good but not in the same class as the L

There appears to be an issue with DO lenses regularly reported on Fredmiranda, and that is contrast in anything less than good light, added to the very high cost (£850) for a lens which has the same aperture as the £89.00 Sigma version. It's also more than double the cost of the equivalent Canon version. I've never seen one outside of a shop so I don't think they've been a success sales wise, it's unlikely you would see a decent return if you need to sell it on.

As an alternative you might consider the Sigma 100 - 300mm f/4 which is reportedly a superb optic and it's faster than the Canon too. You can pick them up on eBay at a reasonable cost.

[Robster]

Hi Flake & ap4a

Thanks for the info it has been most helpfull, with regards to Sigma I have also been told (how true I dont know) that like TVs there are only a handfull of lens manufacturers and that canon use them to produce there top end lenses?
any thoughts.

Robster

[flake]

Erm I don't know who's told you that but it's not right! Canon certainly produce their own lenses and there is a video here which shows the Canon lens production facility and follows a high end lens in its construction.

Canon don't even give the details of the auto focus algorythms to third party manufacturers, they have to reverse engineer them, which gives some people concerns over the efficiency and long term compatability.

Certainly optically it is possible for third parties to produce lenses which are every bit as good as the Canon own brand lenses.

[Chris George]

Originally Posted by Robster

Hi Flake & ap4a

Thanks for the info it has been most helpfull, with regards to Sigma I have also been told (how true I dont know) that like TVs there are only a handfull of lens manufacturers and that canon use them to produce there top end lenses?
any thoughts.

Robster

It is true there are only a handful of lens manufacturers - but Canon is one of them!