Leica SL3 low light autofocus

[Biotar]

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Yes - on stage you often have more light contrast than the necessary texture contrast for AF - it's not always the lack of brightness.

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[frame-it]

48 minutes ago, DirkZ said:

Yeah funny, shooting a gig on stage has more light than what I have shot in my room. It looks brighter on the image than it was in reality.

not always, and the musicians would be moving, sometimes through different lights

[BernardC]

17 hours ago, FlashGordonPhotography said:

1. AFC is a hybrid system, Depending on the lens you choose you’ll get either or both. The SL3 tries to use PDAF first and fine tune the focus accuracy with CDAF at the end of the stroke. If the PDAF initial movement fails the camera moves to a CDAF system. Some lenses seem to initiate CDAF. Maybe they can’t take the torque of a PDAF system. Leica had the same issues with the S system a while back. Many motors were stripped of their gears. I guess Leica is being conservative to start with. It does appear that Leica is reducing torque and applying a CDAF bias to some but not all lenses. And PDAF wasn’t the issue here. The Q has CDAF only as well. The more lenses I test on the SL3 the more variations I get in how the camera treats lenses in AFC.

Just a note: all on-sensor PDAF systems work the same way, regardless of brand. The initial movement is set via PDAF (unless the image is so far out of focus that the sensor can't see a phase difference), and then CDAF takes over if there is enough time. That's because PDAF has limited accuracy.

The S-system lens gear issue was caused by a nylon gear that degrades over time. It isn't necessarily caused by torque; lenses failed regardless of how they were used. SL lenses use completely different motors that don't have these gears. They also have much lighter focusing groups to move, and no mechanical connection to the focus ring. So far we haven't heard of any chronic AF motor failures in SL lenses, although I'm sure that occasional failures happen, as with every brand. That's not to say that all SL lenses focus equally fast, of course.

[FlashGordonPhotography]

7 hours ago, BernardC said:

Just a note: all on-sensor PDAF systems work the same way, regardless of brand. The initial movement is set via PDAF (unless the image is so far out of focus that the sensor can't see a phase difference), and then CDAF takes over if there is enough time. That's because PDAF has limited accuracy.

The S-system lens gear issue was caused by a nylon gear that degrades over time. It isn't necessarily caused by torque; lenses failed regardless of how they were used. SL lenses use completely different motors that don't have these gears. They also have much lighter focusing groups to move, and no mechanical connection to the focus ring. So far we haven't heard of any chronic AF motor failures in SL lenses, although I'm sure that occasional failures happen, as with every brand. That's not to say that all SL lenses focus equally fast, of course.

My S120mm gear failed less than a week after purchase. My 70 and 35 both failed when I put them on the S007 for the first time. The 70 was three months old at the time. I was told directly that the cause was the torque the new PDAF system on the S007 had was too much for the nylon gears. I’m pretty confident on this one. I also believe that most other incidents from other users all seemed to happen in one period. There was quite the stink about it.

Gordon

[Smogg]

The X2D focuses much worse with negative exposure compensation or when the image on the screen is dark. By disabling Exposure Preview (works in M mode only) the situation improves significantly. Try disabling Exposure Preview (simulation) on SL3

[Photoworks]

1 hour ago, Smogg said:

The X2D focuses much worse with negative exposure compensation or when the image on the screen is dark. By disabling Exposure Preview (works in M mode only) the situation improves significantly. Try disabling Exposure Preview (simulation) on SL3

what are you saying, if that is the way to use the SL3 I just get a camera that works

[Smogg]

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6 hours ago, Photoworks said:

what are you saying, if that is the way to use the SL3 I just get a camera that works

For example, in very contrasty scenes on the X2D, in order to save highlights, I make exposure compensation -3. The screen becomes very dark in this case and the camera begins to have huge problems focusing. Switching from aperture priority mode to M mode allows you to disable Exposure simulation (P-A-S instead of P-A-S-M) and autofocus becomes possible again. On the Leica SL3, exposure simulation is also disabled only in M mode, so I do not rule out that this could help.

Edited June 5, 2024 by Smogg

[FlashGordonPhotography]

Adding gain to the sensor in preview helps most mirrorless cameras AF in low light, sometimes.

Gordon

[SrMi]

10 hours ago, Smogg said:

The X2D focuses much worse with negative exposure compensation or when the image on the screen is dark. By disabling Exposure Preview (works in M mode only) the situation improves significantly. Try disabling Exposure Preview (simulation) on SL3

Yes, many (all?) cameras depend on the EVF video stream to focus. If the EVF is dark, the camera may hunt. Some cameras even automatically brighten the EVF for a short time while focusing.

[Smogg]

2 hours ago, SrMi said:

Yes, many (all?) cameras depend on the EVF video stream to focus. If the EVF is dark, the camera may hunt. Some cameras even automatically brighten the EVF for a short time while focusing.

Then the conclusion is simple: if you want to shoot in low light, switch to M mode and turn off Exposure simulation

[SrMi]

32 minutes ago, Smogg said:

Then the conclusion is simple: if you want to shoot in low light, switch to M mode and turn off Exposure simulation

You need to turn off exposure simulation only if the EVF is dark, independent whether shooting in low or bright light.

[BernardC]

14 hours ago, FlashGordonPhotography said:

My S120mm gear failed less than a week after purchase. My 70 and 35 both failed when I put them on the S007 for the first time. The 70 was three months old at the time. I was told directly that the cause was the torque the new PDAF system on the S007 had was too much for the nylon gears. I’m pretty confident on this one. I also believe that most other incidents from other users all seemed to happen in one period. There was quite the stink about it.

I had one lens fail straight out of the box at a dealer, only ever mounted on my S-006. I got a good deal on that lens, the only negative was a short wait for a round trip to Wetzlar. People on the S forum have reported gear failures on lenses that were only used on an S2.

I don't doubt that someone told you that the S-007's "torque" was the root cause, but maybe Leica hadn't yet realized the full extent of the problem. That little gear will eventually fail on every S lens, regardless of what the owner does. The good news is that Leica found a fix and fixed existing lenses. It's mostly behind us now (my 70 hasn't failed yet...).

That's mostly off-topic, of course. My point was that SL lenses don't focus in the same way. They are immune because they don't have tiny nylon gears.

[JiriS]

8 hours ago, Smogg said:

Then the conclusion is simple: if you want to shoot in low light, switch to M mode and turn off Exposure simulation

I can try this suggestion next time (my next gig is 21 June) and will report back. I was shooting with exposure compensation between -2 and -3 EV (but again I also had the same compensation dialled in on the Q and it worked fine). 
 

I was shooting mostly AFs. I did try AFc with face detection but that didn’t work too well so I switched back to AFs. I didn’t play with the more detailed AFc settings yet so that’s something I can look into as well. 
 

Here are few shots from the event to illustrate the lighting conditions. 
 

 

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[jayoco]

One more suggestion.  Turn OFF Pre AF.

[SrMi]

On 6/4/2024 at 2:49 PM, Smogg said:

The X2D focuses much worse with negative exposure compensation or when the image on the screen is dark. By disabling Exposure Preview (works in M mode only) the situation improves significantly. Try disabling Exposure Preview (simulation) on SL3

Yes. Most cameras rely on the EVF/LCD stream to acquire focus. If the subject under the focus point t is too dark, the focus may start to hunt. Making the EVF brighter avoids hunting. The brightness point at which the camera has problems acquiring focus varies with the camera model.

I wish SL and X2D would also allow turning off exposure preview in automatic modes (currently available only in M mode).

[swatch]

I begin to appreciate the design of Hasselblad XCD lenses which allow user to switch to manual focus (when really needed desperately) with distance scale on lens barrel (quick visual for zone focus).

My feeling is Leica is great on optic and mechanic but not like Apple being great on designing product to fit for user habits/usual ways of operating things.  IMO Leica needs to put more effort of UX in product design.

[SrMi]

3 minutes ago, swatch said:

I begin to appreciate the design of Hasselblad XCD lenses which allow user to switch to manual focus (when really needed desperately) with distance scale on lens barrel (quick visual for zone focus).

My feeling is Leica is great on optic and mechanic but not like Apple being great on designing product to fit for user habits/usual ways of operating things.  IMO Leica needs to put more effort of UX in product design.

I always run my SL cameras in MF mode, autofocusing on demand using the joystick button (BBF). I agree that the haptics of XCD V lenses are excellent for manual focusing.

[JiriS]

6 hours ago, swatch said:

I begin to appreciate the design of Hasselblad XCD lenses which allow user to switch to manual focus (when really needed desperately) with distance scale on lens barrel (quick visual for zone focus).

My feeling is Leica is great on optic and mechanic but not like Apple being great on designing product to fit for user habits/usual ways of operating things.  IMO Leica needs to put more effort of UX in product design.

I have a custom button set up to quickly toggle between AF and MF with a single click. I use this quite a lot and when in MF, my joystick is set to autofocus on press. This works great with 35mm APO SL. Unfortunately the AF/MF custom button doesn’t work at all with my Sigma 50mm f1.2 which uses mechanical AF/MF switch instead. When shooting vertical, I found the switch a little hard to access and would much rather prefer to control the Sigma’s AF/MF in the same way I do with the 35 APO SL. 

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[swatch]

1 hour ago, JiriS said:

I have a custom button set up to quickly toggle between AF and MF with a single click. I use this quite a lot and when in MF, my joystick is set to autofocus on press. This works great with 35mm APO SL. Unfortunately the AF/MF custom button doesn’t work at all with my Sigma 50mm f1.2 which uses mechanical AF/MF switch instead. When shooting vertical, I found the switch a little hard to access and would much rather prefer to control the Sigma’s AF/MF in the same way I do with the 35 APO SL. 

What you do is helping SL 35 APO to focus faster:look at EVF to manual focus to desired distance range then press joystick to finish the last work of focus on your target.  Am I understand it correctly?

Edited July 8, 2024 by swatch

[swatch]

7 hours ago, SrMi said:

I always run my SL cameras in MF mode, autofocusing on demand using the joystick button (BBF). I agree that the haptics of XCD V lenses are excellent for manual focusing.

I mount M lens on SL camera as I wait for Leica to reduce the size of native SL lenses:Leica can design/produce Summicron-M 35 apo in compact form that even double the size of it will still be perfect size for autofocus SL lens.

Once that happens then it justifies premium price for Leica product/user experience.