SL3-s autofocus recommendations

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So, I recently picked up the SL3-s and plan on using it for weddings, couples, families, exc. I've had a Canon R5, Nikon Z8, Sony a7rv, and a few others over the last few years. I've been waiting for Leica to get closer to the other brands with their autofocus and after much research, I finally pulled the trigger. I'd like to go all in and have my fun camera (Q3 and possibly m11) and my work camera all be Leica. I love all of it. All that to ask, does anyone have a recommendation for the best eye autofocus settings for people walking towards you? Is there anything I should be changing to get the best results? I understand the hit rate will be less than the other brands I mentioned. I'm totally fine with that. I just want to make sure I'm set up to get the best that I can. Thanks in advance!! 

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[SolarChronicle]

There’s not much to expand on here. Just make sure you’re in AF-C and your AF area mode is set eye/face/body detection. Turning on “Pre-focus” might help too. 

[jaapv]

If they are just walking, taking single shots on AFS should work as well, or maybe better as you will have more control over the moment. 

[Photoworks]

Keep in mind that AFS, in contrast, only the face and body still work well until the light goes down, and you will have a hard time with AFs

Use AFC to get the phase focus activated for better, faster focusing.

 

[Collin]

Thanks guys! That’s another reason I love Leica. I’m not missing anything like fine tuning or weird focus modes. It’s super straight forward. I’ve been getting the best results just using afc and eye detect. 

[LD_50]

1 hour ago, Collin said:

Thanks guys! That’s another reason I love Leica. I’m not missing anything like fine tuning or weird focus modes. It’s super straight forward. I’ve been getting the best results just using afc and eye detect. 

There are settings available even on Leica to fine tune the AF. The system is less capable than Nikon, Sony, Canon but sufficient for the use case you’re describing. The complexity of “fine tuning” and “weird focus modes” is actually an advantage of the more capable systems. You can also ignore it in those systems or with Leica if you accept default results.

For eye AF and people moving the lens will matter, as will your chosen DOF. Example is the 50 SL Summilux that focuses fairly slowly and causes the hit rate on the eyes to drop with movement with shallow DOF.

 

[Elliot Harper]

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On 8/2/2025 at 11:18 AM, Photoworks said:

Keep in mind that AFS, in contrast, only the face and body still work well until the light goes down, and you will have a hard time with AFs

Use AFC to get the phase focus activated for better, faster focusing.

 

I didn't know phase detection only works with AFc. Or am I misunderstanding you?

[jaapv]

It is not as clear-cut as some posters assume: 

I find these quite useful articles.

https://www.picturecorrect.com/phase-vs-contrast-autofocus-systems-on-cameras/

https://josephineremo.com/phase-detection-vs-contrast-detection/

[carlosgavina]

Quote

I didn't know phase detection only works with AFc. Or am I misunderstanding you?

If im not mistaken this is the case at least on Sony as well.

[MikeZ]

On 8/7/2025 at 5:51 AM, carlosgavina said:

Quote

I didn't know phase detection only works with AFc. Or am I misunderstanding you?

If im not mistaken this is the case at least on Sony as well.

I've searched through the SL3-S user guides/manuals and cannot find any mention of the this, neither confirming nor denying, and for that matter no mention of the type of AF points used.  I have noticed some difficulty focusing on verticals while in AFs mode, which lends credence to the conversation, but it's all so curious to say the least.

[Photoworks]

1 hour ago, MikeZ said:

I have noticed some difficulty focusing on verticals while in AFs mode, which lends credence to the conversation, but it's all so curious to say the least.

That is a technology limitation!

it is an old video, but it is the same today

Edited August 8 by Photoworks

[MikeZ]

Thanks for the video.  Great information and a clear visual presentation of the different auto-focus technologies.  I'm aware of those, but I guess at this point I just need confirmation to my understanding of your post from Saturday that AFs is contrast based and AFc is phase based.  That's the info that I couldn't find in any of the manuals.  I suppose that having both simultaneously is not an option.