Jman13 Offline Upload & Sell: On
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p.1 #1 · p.1 #1 · Really disappointed in the RF 100mm f/2.8L Macro | |
So yesterday, I decided to consolidate my macro lenses, of which I have the RF 85mm f/2 and the Laowa 100mm f/2.8. I picked up the RF 100mm f/2.8L IS, and while I had read some reviews that mentioned some focus shift at certain distances, I also read tons of positive reviews. I should have paid closer attention to the reviews that went into focus shift.
I got the lens home, was super impressed by the sharpness, contrast and bokeh at f/2.8 for portraits. Macro stuff looked ok, but I was just messing around. Took some more shots, and started noticing that stopped down the center didn't seem quite as sharp as I was expecting given my experience with other macro lenses...and a little disappointing given the $1,400 price tag. Then I did some controlled tests.
The lens has no real visible focus shift when focusing at very close magnifications (1x, 1.4x, etc). It also doesn't really have a problem beyond about 8 feet. But in between, the focus shift is extremely noticeable, and rather pronounced, and for my uses (where a large portion of my work is in that 0.5x to 0.2x magnification, including medium format film scanning), it is just unacceptable. The focus shifts a bit at f/4, quite a lot at f/5.6 and a ton at f/8. Enough that stopped down head and shoulders portraits (like studio work) would have the eyes go out of focus. Mid-range macro work with large insects like butterflies and dragonflies would make it near impossible to hit precise focus when stopped down. Because RF lenses cannot focus when stopped down (either AF or manual), you have to 'guess' how far to manually focus in front of your subject to get perfect focus at f/8, which is sort of crazy.
So before I 100% decided to return the lens, I did controlled tests, which 100% confirmed the issue. See below for results. This is my Laowa 100mm on the left, with the RF 100mm macro on the right. Both were shot tripod mounted with flash on a self timer, so 100% no shake involved, and distance perfectly consistent. The dollar bill is at around a 45 degree angle to show distance shift. The RF 100 has a little bit more magnification at this exact focus distance, but it doesn't matter much. Focus was manually done on the eye in the dollar bill with 10x magnification, then left alone for each shot, f/2.8 through f/8 - notice how the Laowa just gets sharper and sharper, with more DOF, while the RF lens just shifts its focus further and further backward, leaving the eye out of focus. By f/8, the actual focus point is all the way at the right side of the crop (which at this distance is almost a full centimeter behind where the lens was focused).
The Digital Picture reached out to Canon, who confirmed this is a design decision, and fully expected behavior, not a problem with any lens copies. I am astounded they haven't released a firmware update that will compensate for the focus shift based on focus distance and selected aperture. It should not be that hard to implement. In the meantime, back it goes.
Here are 100% crops of the focus area between the two lens at those apertures..this is at about 2.5 feet distance: Right click and select 'open image in new tab' if FM is shrinking the image to fit the borders a bit.

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