Is the SL3 faster autofocus than SL2-s ?

[LD_50]

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47 minutes ago, Tailwagger said:

A bit of clarification. I have, what a $25K+ investment in SL glass, and even more in M.  Couldn't go back if I wanted to, which I don't for any number of reasons. I came to Leica via Nikon->Canon->Fuji a long time ago.  The M was my first Leica and remains, after over a decade, my primary camera.  The SLs came to the party later. My comment around simple reliable AFs is solely aimed at the SL and its performance in low light.  Let's just agree to disagree about the level of interface complexity in those cameras and the other viable L-mounts ones:

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Like any long term marriage, its for better or for worse.  If what you're saying, and there seem to be many conflicting opinions on this subject, that the SL3 represents a leap in low light AF performance over the SL2 with little need to fuss about with multiple metering and tracking modes to have a high rate of success, then cool, I'll be happy. But if not, I won't.

I’ve been happy with the SL3-S in all conditions in terms of AF speed and accuracy. I can’t speak to the SL3. I’m also shooting AFc with back button press to simulate AFs behavior (not continually refocusing when I don’t press the button). My previous experience is Nikon and the only things I find lacking are tracking and AF at high fps. 

[Tailwagger]

39 minutes ago, LD_50 said:

I’m also shooting AFc with back button press to simulate AFs behavior (not continually refocusing when I don’t press the button).

I've always had a bit of aversion to back button focusing, having spent far too many years half press recomposing. There was a period back with the earliest Fuji X cams where I managed to build a relationship with back button exposure lock.  Not sure I can retrain at this late date, but perhaps its worth a try.

[LD_50]

Just now, Tailwagger said:

I've always had a bit of aversion to back button focusing, having spent far too many years half press recomposing. There was a period back with the earliest Fuji X cams where I managed to build a relationship with back button exposure lock.  Not sure I can retrain at this late date, but perhaps its worth a try.

I find it’s pretty nice on the SL cameras because I’m already using the joystick to select focus point. I never really liked having the separate AF ON button on Nikons though you can customize to use a joystick press on those as well. 

[Photoworks]

My challenge with the back button focus is to remember that it is active and get a muscle memory going.

All until the SL3 crashes and changes profile, and the back button focus is no longer active. To me, it is only a temporary solution.

Tonight I did a shoot on the SL3, TV studio outdoors at night. I was using the AFC and a field selection.  Since AFC soften the image on the OLED EVF, it is almost disturbing that the soft picture in the EVF is going to resolve to a Sharp image.  The combination of high ISO made it only worse.

I assume you have one of the latest Sony a7R's and it can look even worse, but the Sony can be switched to AFs and it works great.

For the people, they suggest knowing the craft to get a photo in focus. Well, I would not have to guess why AFs is not great, and Leica non putting phase on AFs is a big let down.

I suppose they only took the tech from Panasonic, but again, it is still disappointing to find out after spending 7K on a camera. 

[SrMi]

23 minutes ago, Photoworks said:

All until the SL3 crashes and changes profile, and the back button focus is no longer active.

That is really weird, should not be happening, and it does not happen with my SL3 cameras.

23 minutes ago, Photoworks said:

For the people, they suggest knowing the craft to get a photo in focus. Well, I would not have to guess why AFs is not great, and Leica non putting phase on AFs is a big let down.

I shoot in AF-S most of the time and have no issues. It is quick and precise. What are your issues with AF-S?

Edit: You can use PDAF in AF-S mode, kind of. Assign AF-C to the joystick in MF, then press the joystick to focus and release.

Edited November 22 by SrMi

[LD_50]

1 hour ago, Photoworks said:

My challenge with the back button focus is to remember that it is active and get a muscle memory going.

All until the SL3 crashes and changes profile, and the back button focus is no longer active. To me, it is only a temporary solution.

Tonight I did a shoot on the SL3, TV studio outdoors at night. I was using the AFC and a field selection.  Since AFC soften the image on the OLED EVF, it is almost disturbing that the soft picture in the EVF is going to resolve to a Sharp image.  The combination of high ISO made it only worse.

I assume you have one of the latest Sony a7R's and it can look even worse, but the Sony can be switched to AFs and it works great.

For the people, they suggest knowing the craft to get a photo in focus. Well, I would not have to guess why AFs is not great, and Leica non putting phase on AFs is a big let down.

I suppose they only took the tech from Panasonic, but again, it is still disappointing to find out after spending 7K on a camera. 

I don’t know what you’re referring to with crashes. I’ve not had this with SL, SL2-S or SL3-S. 

You’ve made multiple mentions of PDAF not being used in AFs setting. Do you have some evidence of this or documentation from Leica?

[Photon42]

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5 hours ago, Photoworks said:

My challenge with the back button focus is to remember that it is active and get a muscle memory going.

All until the SL3 crashes and changes profile, and the back button focus is no longer active. To me, it is only a temporary solution.

Tonight I did a shoot on the SL3, TV studio outdoors at night. I was using the AFC and a field selection.  Since AFC soften the image on the OLED EVF, it is almost disturbing that the soft picture in the EVF is going to resolve to a Sharp image.  The combination of high ISO made it only worse.

I assume you have one of the latest Sony a7R's and it can look even worse, but the Sony can be switched to AFs and it works great.

For the people, they suggest knowing the craft to get a photo in focus. Well, I would not have to guess why AFs is not great, and Leica non putting phase on AFs is a big let down.

I suppose they only took the tech from Panasonic, but again, it is still disappointing to find out after spending 7K on a camera. 

You live in the US? I think you guys can order stuff, try it for 30 days and then send it back. I cannot do that here, but can ask the Leica store to let me try out a camera for a couple of hours, even days. Helps immensely forming a view before opening 7k.

Phase detection AF tells the camera the focus direction and reasonably accurately the distance offset to bridge. Contrast detection does not do that (that's why we see pumping), but is more precise it the actual focussing. It is not uncommon to use both technologies in combination. I do not know what Leica uses for the SL3 and AF-S.

I did use BBF for a very long time but have now migrated away from that. Face recognition  and are good enough now for my purposes and actually after to operate with one button only.  I can still move the focus point if I am on single focus. Tracking is also an often forgotten tool which works ok on not too critical stuff (like f 1.2 1m distance or so). Tracking is also continuously focussing.

[Photoworks]

9 hours ago, SrMi said:

That is really weird, should not be happening, and it does not happen with my SL3 cameras.

I shoot in AF-S most of the time and have no issues. It is quick and precise. What are your issues with AF-S?

Edit: You can use PDAF in AF-S mode, kind of. Assign AF-C to the joystick in MF, then press the joystick to focus and release.

I have gotten crashes on the SL3 every few weeks. Mostly shooting in the studio with flash or on events with SF 60. 
The SL2 never had a problem for me, the most stable Leica camera from relise.

Some of the Panasonic S lenses are giving problems on the SL3, they need to get a firmware update going.

I have submitted to Leica a list of 20 firmware improvements needed for the SL3 a year ago, the only one addressed is the Camera deleting images involuntarily.

I don't like to use BBF , I need a working system. I use many different cameras, and which one is with BBF is not an option.

I have fun with issues with AFs in low light, hunting, and not focusing.  Backlight in an office using flash does not work in AFs. I have no need for a system that just works on sunny days.

[Photoworks]

8 hours ago, LD_50 said:

You’ve made multiple mentions of PDAF not being used in AFs setting. Do you have some evidence of this or documentation from Leica?

They don't talk about it, but all marketing material always shows AFs. But you can just test the SL2 and SL3 yourself, and you can see there is no difference in AFs. The Miami people talk about it on YouTube too. And the Panasonic is the same.

[Photoworks]

3 hours ago, Photon42 said:

You live in the US? I think you guys can order stuff, try it for 30 days and then send it back. I cannot do that here, but can ask the Leica store to let me try out a camera for a couple of hours, even days. Helps immensely forming a view before opening 7k.

Sure, you can, or you can wait until people have tested it and report on it.

I got the SL3 in the Leica Store in NYC, supporting local business. I have tested it the day before it came out, but the limited time with it didn't show the flows or the testing in the situation you find yourself as a photographer.

Don't get me wrong, the SL3 is still a great camera, and AFc is finally usable over the SL2. But we need a refined SL3 firmware.

[LD_50]

5 minutes ago, Photoworks said:

They don't talk about it, but all marketing material always shows AFs. But you can just test the SL2 and SL3 yourself, and you can see there is no difference in AFs. The Miami people talk about it on YouTube too. And the Panasonic is the same.

What I’ve seen from Leica simply says: 

• Hybrid Autofocus System (Phase Detection AF + Contrast AF + Object Detection AF + AI)

and

• With phase detection (PDAF), depth mapping (Object Detection AF), and contrast recognition (Contrast Detection AF), the innovative autofocus system of the SL3 combines the strengths of three technologies…

Technical specs (for SL3) says:

• Hybrid-AF due to combination of contrast metering, depth mapping, and phase comparison metering with AF metering points

  in the sensor.

Where are you seeing something that says PDAF doesn’t work in AFs?

Regarding testing - how would you test to determine PDAF is or is not working? 

[Photoworks]

2 minutes ago, LD_50 said:

Where are you seeing something that says PDAF doesn’t work in AFs?

Regarding testing - how would you test to determine PDAF is or is not working? 

Leica Marketing shows in all the videos the show how great AF is now with PDAF with Contrat.  

You can test it in all the situations where contrast AFs struggle. 
Try setting your camera to 3200 ISO in a low-light room, try it with AFs, take a few shots, try the same in AFc, and you can see the difference.

Typically, I get 2-3 usable shots of 5-6 in AFs with refocusing, and in AFc, they are all in focus, I use flash, so the room is 1 stop underexposed. The distance from the people subjects does not change; this was one of the reasons to get away from the SL2.

[LD_50]

41 minutes ago, Photoworks said:

Leica Marketing shows in all the videos the show how great AF is now with PDAF with Contrat.  

You can test it in all the situations where contrast AFs struggle. 
Try setting your camera to 3200 ISO in a low-light room, try it with AFs, take a few shots, try the same in AFc, and you can see the difference.

Typically, I get 2-3 usable shots of 5-6 in AFs with refocusing, and in AFc, they are all in focus, I use flash, so the room is 1 stop underexposed. The distance from the people subjects does not change; this was one of the reasons to get away from the SL2.

I don't follow what you've written regarding Leica marketing. I think you're saying that when they show videos of AF performance, they always show AFc in use? 

Is there actually something published somewhere from Leica that states PDAF is not used in AFs? 

 

I just tested with the following settings in a dimly lit room:

SL3-S, 24-90 at 90 f/4, ISO 3200, 1/200

12 shots with AFs, 12 shots with AFc -  all with field 

Target 1: 6 shots underexposed 2 stops, Target 2: 6 shots underexposed closer to 3 stops

Results:

Target 1: the camera locked in focus with similar speed, maybe the AFc was slightly quicker on several of the shots, 6 of 6 in focus with AFs, 6 of 6 in focus with AFc

Target 2: the camera racked focus to lock in with both AFs and AFc. 6 of 6 in focus with AFs, 5 of 6 in focus with AFc. 

Normal lighting:

I tried multiple shots with normal lighting, with proper exposure. AFs and AFc achieve the same results and it appears with AFc the focus "snaps" slightly faster than with AFs. AFs is still very quick but does seem to "wobble" (likely indicative of CDAF). 

Comments:

This wasn't a blind test, as I knew which setting I selected.

• The normal lighting scenario seemed to show AFs using CDAF first, and AFc using PDAF first.
• The target 1 scenario seemed to show the same, but only some of the time
• The target 2 scenario seemed to show both settings trying everything possible to achieve focus with no difference in acquisition time, behavior, or accuracy. 

I don't think the results are conclusive regarding use of PDAF and/or CDAF between AFs and AFc, though there is some difference in behavior. I think a scientific test with proper AF target could tease out whether there is any real difference in actual target acquisition.

I think it would make sense for any camera to default to PDAF first when tracking and/or speed is desired (AFc scenario) and CDAF first when speed can be sufficient and accuracy can be improved (some AFs scenarios). I would expect a complex interaction between the focus types available rather than a simple AFs=CDAF and AFc=PDAF.

[Eliseo]

On 11/17/2025 at 3:17 PM, jaapv said:

Good question. The system should be faster and the high MP should slow it down. I would say that you need an Sl3S to find a real difference or better still one of the Panasonic S cameras. 

Thank you!!

[Eliseo]

On 11/17/2025 at 3:57 PM, jaapv said:

If he means the Sigma 60-600  Sports or 150-600 Sports, those are not amongst the fastest lenses. The 70-200 Sports is a lot faster. 

Thank you!, Imean the Sigma 300-600 F4, I know it is a fast lens on other cameras

[Photoworks]

50 minutes ago, LD_50 said:

I don't follow what you've written regarding Leica marketing. I think you're saying that when they show videos of AF performance, they always show AFc in use? 

Yes

50 minutes ago, LD_50 said:

Is there actually something published somewhere from Leica that states PDAF is not used in AFs? 

No

just like many other things, like IBIS+IS. 

[SrMi]

The only official information about AF is that the Leica SL3 uses a hybrid system. From Leica:

The SL3’s autofocus system combines three technologies using efficient algorithms. Depending on the shooting situation, the interplay of phase detection (PDAF), depth map (Object Detection AF), and contrast detection (Contrast Detection AF) are optimally adjusted.

 

[colonel]

On 11/20/2025 at 2:18 PM, Photoworks said:

i would assume that a few factors are at play here.

Sigma lenses from the last year do have faster motors that what came before from them.

Leica Lenses are marketed as fast focusing, but in reality, they are slower the most sigma lenses.

Adapted lenses are probably not great in AF in most situations.

SL2 has the same system of SL3 in AFs, based on contrast AF

The bigger change is in AFc, continuous AF introduces PHASE + CONTRAST, which makes a big difference in focus speed and stickiness.

I use SL2 and SL3 side by side, and I wish phase AF would be an option in AFs, It was one of the reasons to get the SL3 camera, but Leica never said that it was not implemented in AFs.

Contrast AF is ok when used in situations with good lighting, the SL2 struggles in backlight or High ISO situations, and the hunting becomes very frustrating.

 

If sports or wildlife is your main interest, I would stick with Canon, Nikon, or Sony. They just are much better at it.
Panasonic in the newer camera has the same AF as Leica, maybe a better implementation in the software, but AFs and AFC are the same.

Absolutely, where it counts, SL3 AF is much faster and more accurate

[Tailwagger]

Does the SL3 hunt, like the SL2, in low light?  If so, odds are theres no PDAF involved. 

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Hallo,

Look here: Leica L-Mount

[SrMi]

52 minutes ago, Tailwagger said:

Does the SL3 hunt, like the SL2, in low light?  If so, odds are theres no PDAF involved. 

Cameras with PDAF often switch to CDAF in low light.