scalanc2 wrote:
Some SAR detractors should take a pause now.
This is and was had nothing to do with this lens period . I don’t even care about this lens . It does have everything to do with click bait site that is horrific and always has been with terrible info. You can’t defend them on any reasonable level. You wanna read trash that’s on you.
● Lens construction: 15 elements in 11 groups, with 1 FLD, 1 ELD, 2 SLD and 2 aspherical elements
● Internal focusing ● Compatible with high-speed autofocus
● Stepping motor
● Compatible with lens-based optical correction
* Function available on supported cameras only. Available corrections may vary depending on the camera model.
● Super Multi-Layer Coating
● Water and oil repellent coating (front element)
● Aperture Ring
● Aperture Ring Click Switch
● Aperture Ring Lock Switch
*When turned ON at the position A, the aperture ring is locked at A. When turned ON at a position other than A, it is locked within the range between the maximum to minimum apertures and will not engage at the position A.
● AFL button
● Focus Mode Switch
● Support DMF, AF+MF
● Dust and splash proof structure
● Petal type hood with lock
● Compatible with SIGMA USB DOCK UD-11 (sold separately / for L-Mount only)
● Designed to minimise flare and ghosting
● Every single lens undergoes SIGMA’s proprietary MTF measuring system “A1” ● 11-blade rounded diaphragm
● High-precision, durable brass bayonet mount ● ‘Made in Japan’ craftsmanship
j4nu wrote:
So it seems Sigma has completely moved from HSM to stepper motors, even in Art line...
I don't think I've seen "HSM" for a mirrorless ("DN") lens and my impression is that the HSM focus motor is for DSLRs.
Edit. Slightly too late
Will be interesting to see whether it's any sharp wide open centrally at mfd; sometimes I think about replacing my Canon 35/2 IS USM; it + the MC11..weighs less than this lens but both fit in my messenger bag with a camera.
Maybe Sigma doesn’t have Sony’s linear XD motors to provide the required torque in Sigma’s case or in Sony’s case just force.
The new 35/1.4 DG DN has a focus group consisting of only one light lens element, according to the press text on SAR. That may explain how Sigma gets away with a stepper motor in this case. I see that Sony uses dual XD motors even on the new small 24/2.8, 40/2.5 and 50/2.5 G lenses.
So, stepper motors appear a bit dated to me, and HSM-motors are stone age D(inosaur)SLR tech.
Apr 26, 2021 at 06:18 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
bjornthun wrote:
Maybe Sigma doesn’t have Sony’s linear XD motors to provide the required torque in Sigma’s case or in Sony’s case just force.
The new 35/1.4 DG DN has a focus group consisting of only one light lens element, according to the press text on SAR. That may explain how Sigma gets away with a stepper motor in this case. I see that Sony uses dual XD motors even on the new small 24/2.8, 40/2.5 and 50/2.5 G lenses.
So, stepper motors appear a bit dated to me, and HSM-motors are stone age D(inosaur)SLR tech.
I see no evidence from any reputable site (only gushing by Sony fans) that linear motors are better than stepper motors. Sony has extensively used linear motors most other manufacturer have used stepper motors for their mirrorless lenses. Both technologies are relatively old and borrowed from existing tech (linear motors from speakers and stepper motors from clocks). They are competing technologies without either clearly being better than the other.
Steve Spencer wrote:
I see no evidence from any reputable site (only gushing by Sony fans) that linear motors are better than stepper motors. Sony has extensively used linear motors most other manufacturer have used stepper motors for their mirrorless lenses. Both technologies are relatively old and borrowed from existing tech (linear motors from speakers and stepper motors from clocks). They are competing technologies without either clearly being better than the other.
« Two independent floating focus groups allow for close focusing distances, and are driven by four 'extreme dynamic' linear motors (two per focus group). We're told by Sony that these linear motors are very efficient at generating linear motion, as they don't require any translation of rotational motion to linear motion, as ring-type and stepper motors do.»
and
« In comparison, the tiny FE 35mm F1.8 optic takes 0.3s to rack from its minimum focus distance to infinity, while the Nikkor 35mm F1.8 S takes around 1s to do so. That makes the 0.5 - 0.6s figure for the 50mm F1.2 GM nothing short of impressive.»
« Two independent floating focus groups allow for close focusing distances, and are driven by four 'extreme dynamic' linear motors (two per focus group). We're told by Sony that these linear motors are very efficient at generating linear motion, as they don't require any translation of rotational motion to linear motion, as ring-type and stepper motors do.»
and
« In comparison, the tiny FE 35mm F1.8 optic takes 0.3s to rack from its minimum focus distance to infinity, while the Nikkor 35mm F1.8 S takes around 1s to do so. That makes the 0.5 - 0.6s figure for the 50mm F1.2 GM nothing short of impressive.» ...Show more →
To be honest, it's impossible to settle in the Sony land because Sony rarely uses stepper motors and when comparing AF performance to Sigma lenses other factors may come into play (algorithms, etc.).
One thing that seems to point towards linear motors is that Tamron switched to them in their big and fast glass (70-180 and 150-500).
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