Here is the Canon RF 100mm f/2.8L IS USM Macro

I almost guarantee you that the SA adjustment ring is related to a macro function. It would make absolutely no sense for Canon to add excess portrait-related features to a professional high-end 1:1 macro lens, I know people use this for portraits, but the point of a 1:1 macro is... macro. I'm more willing to believe that the SA is for focus bracketing, or possibly for higher than 1:1 macro. Possibly "Step Adjustment control?"


Sidenote: It happens a 25mm extension tube gives you 1.4X life size on a 100mm macro. If the patent says there's a 1.4X macro, I wouldnt be surprised if this pulls off some sort of internal extension tube for bonus macro lengths.
 
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This has the potential to be the first RF lens that is first to market with a very useful new feature depending on what that SA feature does and how well it does it. Not saying that the existing RF lenses haven’t proven they’re worth their weight (if not the gold it takes to get a hold of them) but firsts like these can be pretty great at spurring innovation from the third parties.
 
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I almost guarantee you that the SA adjustment ring is related to a macro function. It would make absolutely no sense for Canon to add excess portrait-related features to a professional high-end 1:1 macro lens, I know people use this for portraits, but the point of a 1:1 macro is... macro. I'm more willing to believe that the SA is for focus bracketing, or possibly for higher than 1:1 macro. Possibly "Step Adjustment control?"


Sidenote: It happens a 25mm extension tube gives you 1.4X life size on a 100mm macro. If the patent says there's a 1.4X macro, I wouldnt be surprised if this pulls off some sort of internal extension tube for bonus macro lengths.
The patent shows the lens groupings sliding in and out. This would achieve both stepping for focus bracketing and magnification changes. I’m really excited to see how this works. I’m over fiddling with bracketing for my macro work!
 
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An intriguing new ring... :) but I also see one drawback right away. They removed the optional collar the EF version had. It is pity. I do like better stability it adds to a setup on a tripod.
 
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If the SA is to control spherical aberration it might work similar to the defocus control on Nikon's old 105/2 and 135/2 DC lenses. I believe the idea was to shift the DOF in front of and behind the subject, the effect was subtle.
 
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If "SA" means "Slider Adjust" and many are hoping for auto bracketing in camera, why is there a ring with markings? That tells me they assume manual adjustment.

It would seem that the increments would vary for every subject.
Can anybody help me understand?
 
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Spherical aberration control between - and + would enable control over which side of the focus plane gets smoother and which one more "ringy" bokeh, like below. It occurs to me that combined with focus stacking, it might be possible to get the best of both worlds!

1617840917674.png

(source)
 
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If "SA" means "Slider Adjust" and many are hoping for auto bracketing in camera, why is there a ring with markings? That tells me they assume manual adjustment.

It would seem that the increments would vary for every subject.
Can anybody help me understand?
It's not quite a ring, but a few solid stops. I can imagine if this is focus bracketing, every step is a defined amount different backwards or forward from the focused point. That would let you make your focus brackets in specific amounts, and if it's electronic, you could probably define how far of focus every step is.
 
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EF 100mm had closest focus distance of 30cm for 1x this lens has 25cms closest distance based on focus limiter. So does this have slightly higher mag ratio? Really excited for this lens and now will start saving for it, only thing I want is a crop RF body.
 
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I almost guarantee you that the SA adjustment ring is related to a macro function. It would make absolutely no sense for Canon to add excess portrait-related features to a professional high-end 1:1 macro lens, I know people use this for portraits, but the point of a 1:1 macro is... macro. I'm more willing to believe that the SA is for focus bracketing, or possibly for higher than 1:1 macro. Possibly "Step Adjustment control?"


Sidenote: It happens a 25mm extension tube gives you 1.4X life size on a 100mm macro. If the patent says there's a 1.4X macro, I wouldnt be surprised if this pulls off some sort of internal extension tube for bonus macro lengths.
Are you aware that to macro photographers the photo of a plant or insect is actually a portrait, just not a portrait of a person? Can’t believe I have to even say that, LOL.
 
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Are you aware that to macro photographers the photo of a plant or insect is actually a portrait, just not a portrait of a person? Can’t believe I have to even say that, LOL.
I understand that, but there were clearly comments about soft focus, for example, and I don't see any reason why Canon would choose to include that human specific portrait feature on a macro lens of all things. Macro lenses are not at a loss for bokeh, the primary goal of most macro work is to get the most detail and depth of field out of a very shallow depth of field and often diffraction limited sharpness. No one is looking to smooth the skin of a fly.
 
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Quote from the translated Japanese patent:

“For example, the interchangeable lens determines whether or not focusing is instructed by a user or a change in an aberration amount is instructed, and moves the 1 focus group and the 2 focus group with a locus suitable for the purpose.”

From that I think the control ring is to make “a change in an (spherical) aberration amount”
 
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