Dustin Abbott has completed his extensive review of the Sigma 105mm f/1.4 DG ART HSM which is available in the Canon EF mount. Nikon shooters have their own native Nikkor 105mm f/1.4, but the only option for Canon is this new Sigma Art series prime.
Buy the Sigma 105mm f/1.4 DG ART HSM at Adorama
I have yet to get my hands on one of these lenses, but it's definitely going to find a place in my kit in the near future.
Dustin came away impressed with the Sigma with a few caveats:
Sigma has once again successfully created an extreme optical instrument. Tackling a project like a 105mm lens with a huge maximum aperture of f/1.4 is not for the faint of heart, and yet I see evidence of growing maturation as Sigma manages to get more and more right. There’s no question that the extreme size and weight of the 105 ART will be off-putting to many, but those with a little extra arm strength will be rewarded with an exceptional portrait lens. The Sigma 105mm f/1.4 DG HSM ART is not a mainstream lens. It isn’t a general-purpose lens; it is a tool for specialists. A lens like the 105 ART can seriously set your work apart from the crowd, providing images unique to those that a standard 70-200mm f/2.8 lens can produce. Read the full review
Rent the Sigma 105mm f/1.4 DG ART HSM at Lensrentals.com
Oh well, guess I'm first then.
The review noted much improved autofocus performance in the last three Sigma lenses the author had reviewed.
Any speculation as to whether Sigma has been given official access to Canon's AF algorithms and what, if anything, would be in it for Canon?
My guess is avoiding pointlessly costly anti-monopoly complaints - if Sigma could demonstrate Canon had actively worked against third party lens manufacturers they may have had a strong case that was resolved with a bit of cooperation from Canon.
Obviously, Sigma's lens design facilities and their manufacturing automatisation were and possibly still are industry leading.
Could it be possible that there have been technology exchanges between the two companies? Maybe Sigma has shared manufacturing processes with Canon in exchange for access to autofocus algorithms? Not impossible, since Canon is moving to full automatisation with respect to most of their lenses.
Alternatively, this cooperation may be a way for Canon to get a foot in the door so that if an opportunity arises in the future for someone to acquire Sigma Corp. they have first dibs.
Just some thoughts.
Regarding a tie up I suppose that if Canon is going to have to develop a range of new mount lenses in a hurry they’d be able to do it quicker with help from Sigma - or Tamron as Ricoh Pentax seem to have done.
I agree with your point regarding Tamron, except that I've typically achieved those results after some work with the Tap In. The last three Sigma lenses that I've reviewed (all of which were supported in Canon's Lens Aberration Corrections) have not needed ANY calibration to work exceptionally well. I'm finding it hard to believe that Sigma suddenly made that much improvement on their own.
Agreed that a sudden improvement from annoying to perfect on the Sigma would suggest a helping hand.
Incidentally both my Tamrons, the 45 and 85 SP are 0 AFMA at all three settings. Initially my 45 needed some AFMA but after sending it back to Tamron UK for the firmware up date to allow using the Tap-in consule, and stating I was using it on a 5DS, it was perfect at all distances when returned !
I also have the SP45 and SP85 and they are stunningly good lenses. I have not had any issues with AF as I did with several Sigmas.
When the 'Canon wants to buy Sigma' rumor surfaced, I recall reading that Canon would have been interested in Sigma's foveon technology. This interest may still exist.
My brother! Dude, I actually bought both of those lenses due to your very thorough and very informative reviews of them. I love both these lenses and the 45 never leaves my 6DII. Thank you for the work you do. I find it quite helpful to myself, and I'm sure to the community, as well.