Sigma DG vs NonDG Tamron Di vs nonDi

[muko]

Hello Experts...

i kept on wandering around but still cannot found a really good explanation about ths.
only that it is to prevent reflection back from CCD sensors of digital cam.

some says about shoting at light source...

anyone has the experience on comparing between these version and see the differences?

thanks

 

[TME]

The digitally optimised lenses, those with DG, etc are made with lens elements which try to bend the light so that they hit the sensor plane as close to perpendicular as possible. Cos the sensor is pretty reflective and causes significant light scattering as well as ghosting... also as there are microlenses over the sensor sites, light coming in at angle less than perpendicular will cast a shadow on the sensor sites, creating less than optimal images... hence a redesign of the elements is required to make sure that the lenses produce cleaner images... IMO, if u dun shoot under extreme lighting conditions, dun print larger than A3 and dun scrutinse the image using a magnifying lens, it should not make much difference... the pros might see a difference... and the difference will be big and real enough for their work to make them switch although with the lenses they use, this DG range is not within their consideration I guess...

 

[muko]

hmmm...

 

[Agetan]

the benefit of digital version is not great IMHO, it is basically slight improvement but great advertising material for manufacturer...

Hart

 

[muko]

ho..ho..
But Hart... nobody have ever tried before showing samples of DG and NonDG...
That is why effectiveness is still questionable. And since never tried before also that means we also cannot say that it is not effective...

he,..he.. sorry i confused myself..

 

[tankm]

Read an article about this before...there was a comparison done between the DG and Non-DG version of the SIGMA 70-200 f2.8. The final result, the DG is slightly better in terms of contrast. However, the site seems to be SIGMA supporter as well, as there are lots of SIGMA lens review and not of other brands.

Question is, why major lens manufacturer like Canon, Nikon, Zeiss, Olympus, Minolta, Tamron....did not say much about this ? :think:

 

[TME]

Actually all the large manufacturers have moved towards digital-optimised lenses... I guess for most applications there might be imperceptible improvements but for that one shot which is shot in rather drastic lighting the flaws in the original lens design might become very pronounced... so they have all quietly moved to optimise the lenses for digital SLRs... some have chosen to make a huge fanfare, some have decided to do it quietly...

 

[muko]

maybe like those "New" marking on some Minolta lenses?
dunno lah...

 

[Agetan]

There will be some improvement, but I don't think it make so much different..

Well, as a consumer, what do you think when you are buying a DSLR and the sales person sale this lens is optimised for the DSLR and this lens is compatible for DSLR? Most people will pay more for the "Optimised"... how good they are? probably not much.

Hart

 

[TME]

Yeah to me it's not significant so that I change my lens line up to digital also... I think some of the companies are beginning to see that consumers are not so easily fooled...