S3 Autofocus

[BernardC]

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7 hours ago, ben446 said:

I am finding MF / my eyesight-brain is too slow for moving subjects unless I stop down.

That's something you can work on.

My work commute used to take me past a park with waterfowl. I would stop for a few minutes on the way home and sit at the water's edge with my camera, focusing on a bird in the water. This did wonders for my muscle memory, and soon I could keep the bird in focus without thinking. It's similar to a musician learning a difficult piece by starting slow and speeding-up. After a while you aren't thinking about individual notes, but instead you feel where you are in the piece and your body instinctively plays the notes (or moves the plane of focus).

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[Stuart Richardson]

8 hours ago, ben446 said:

When shooting portraits with AF, where do people place the center point of the focus circle? My instinct is to put it on the front eye or the bridge of the nose and then recompose. Does it even matter as long as the focus target is somewhere in the circle? Interested in stopped down and wide open scenarios. I have been using BBF but my hit rate is not great. Was looking to try shutter button AF to see if it's any better. I realize BBF stopped down is probably the answer. I am finding MF / my eyesight-brain is too slow for moving subjects unless I stop down. I use the 'move my head (and camera) back and forth' for macro. Good idea to use it here.

The focusing mechanism in the S is not particularly advanced. In my experience it will grab the highest contrast object within the entire circle that is proscribed by the AF area marking on the focusing screen. Often that is an eye, but sometimes it's frames of glasses or an eyebrow etc. But I would say that I generally did what you did and had pretty good results, but I seldom shot wide open. I don't think the S is really good at focusing perfectly wide open unless you give it a very clear focusing target and enough light. 

I used the S for almost ten years all the way up to the S3, and while I loved the S006 in particular, accurate focus was a challenge that entire time. Not a completely insurmountable one, but it is not a system where you can just set the lens to 2.5 and get spot on focus every time. If you want that, you are better off with the SL system or another brand. What I did to adapt to this while I had the camera was to make multiple photos with different focus attempts: So I would back button focus and take the picture. BBF again, take it again and so on. I also recommend not shooting wider than f4 or so for photos where you don't have time to nail the focus. 

For better or for worse, the S cameras have a focusing system designed 20 years ago, which they never really updated. It got a bit faster, but the tech remained the same and they were limited by it. With all that said, I still found the AF to be more accurate than manual focus. Not because of eyesight, but because the positioning of the focusing screen is so critical to perfect focus, and with lenses as sharp as the S lenses on 37-64mp, shimming and exact placement are paramount. I found that none of my S bodies (I had three) had perfectly shimmed mirrors. Every one was ever so slightly off compared to the AF and live view (in the S3). I spoke to Leica about this and they said it was normal, and the mirror could not be as accurate as the AF sensor or live view. They basically told me that I was asking too much of it. All of these things were reasons why I eventually sold the S cameras and stuck with the SL2. 

Edited August 30 by Stuart Richardson

[ZHNL]

I never trust S autofocus. either WO or stop down shooting. The only time I use it is for close distance WO or stop down shooting. The results are acceptable with good enough repeatability based on my test and experience. I know people talk about this is 15/20 year old tech but actually most of Nikon Canon OVF at that time smoke S's AF in term of speed and accuracy. It will also miss focus, but mostly peripheral focus point or AFC action shot. For center AFS, I can rely on them but not with S. This is just my experience. 

My bar for AF is very low but S didn't meet it. However if you know what you get, this is also not a problem for me to enjoy using the system. 

[Pieter12]

27 minutes ago, ZHNL said:

I never trust S autofocus. either WO or stop down shooting. The only time I use it is for close distance WO or stop down shooting. The results are acceptable with good enough repeatability based on my test and experience. I know people talk about this is 15/20 year old tech but actually most of Nikon Canon OVF at that time smoke S's AF in term of speed and accuracy. It will also miss focus, but mostly peripheral focus point or AFC action shot. For center AFS, I can rely on them but not with S. This is just my experience. 

My bar for AF is very low but S didn't meet it. However if you know what you get, this is also not a problem for me to enjoy using the system. 

How did people ever take pictures before AF? Seems impossible.

[ZHNL]

38 minutes ago, Pieter12 said:

How did people ever take pictures before AF? Seems impossible.

I guess it depends on standard of resolution, or camera with some type of focus aid. For the record, I use manual focus on S because I figured ways how to deal with it and it is highly depend on usage case but I still treat AF as one of biggest negative S system has. 

The debate just like how people travel before Airplane. It is a rabbit hole without outcome.  

Edited August 30 by ZHNL

[Stuart Richardson]

3 hours ago, Pieter12 said:

How did people ever take pictures before AF? Seems impossible.

I guess you are being sarcastic, but talking about the problems of an AF system does not mean one is incapable of using manual focus. Well designed MF is quick and accurate. Questionable AF is neither. The problem was that the S was not ideal with either. The S AF was good compared to other medium format systems of the time, but that is not what it is compared to. I came from a Sinar Hy6 and Rollei 6008AF and the S was a lot better than both. For me at least, the MF was not accurate in the S, at least not accurate enough. You would get close and sometimes it would be fine, but in general the AF was acceptable. It was not as good as Canon and Nikon of the time, but keep in mind it was also stressing the system harder: it was higher resolution with better lenses and much heavier duty glass to move. They did the best they could at the time, but it was outdated pretty much right away. They fixed the most glaring problems in the SL lenses, but people still consider those outdated too, so Leica just can’t keep up with the leaders it seems.  

Edited August 30 by Stuart Richardson

[Pieter12]

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3 hours ago, ZHNL said:

I guess it depends on standard of resolution, or camera with some type of focus aid. For the record, I use manual focus on S because I figured ways how to deal with it and it is highly depend on usage case but I still treat AF as one of biggest negative S system has. 

The debate just like how people travel before Airplane. It is a rabbit hole without outcome.  

Not quite. And certainly not a debate. AF is a crutch, not a necessity unless one is possible photographing sports or fast-moving wildlife. Even then, not a necessity.

[Stuart Richardson]

3 hours ago, Pieter12 said:

Not quite. And certainly not a debate. AF is a crutch, not a necessity unless one is possible photographing sports or fast-moving wildlife. Even then, not a necessity.

That is a very narrow view. Certainly one which does not account for many photographers whose vision is not perfect or easily correctable. Or people with disabilities. One of my former students is a fantastic photographer who has limited use of his right hand, and because of that cannot use manual focus cameras without a tripod. It also does not account for cameras where the AF system was the main design priority and don't feature adequate manual focus aids. I would put the S in that group, though I know not that many would agree with me. But I did many tests over the ten years comparing MF vs the AF confirmation dot and the AF function itself and found the AF to be more accurate. I use manual focus all the time on medium and large format without issue, so the issue was not my vision, it was the accuracy of the system. 

Leica themselves admitted that the mirror did not necessarily exactly match the sensor:

"Dear -----

 

Thank you for letting me know. I look forward to hearing about the rings. Among the other issues I mentioned, the focusing screen does not correspond to the AF sensor (so if you focusing with the optical viewfinder, it is misfocused). Is it Leica’s position that that is also in spec? I ask, because I don’t really feel comfortable selling on a camera that I personally do not think works properly…

 

Best, 

Stuart

Dear Stuart,

 

I received feedback from my colleagues.

 

About the viewfinder. I got the confirmation that the viewfinder can be a little bit different to the sensor.

Mit freundlichen Gruessen / kind regards"

[Pieter12]

18 hours ago, Stuart Richardson said:

That is a very narrow view. Certainly one which does not account for many photographers whose vision is not perfect or easily correctable. Or people with disabilities. One of my former students is a fantastic photographer who has limited use of his right hand, and because of that cannot use manual focus cameras without a tripod. It also does not account for cameras where the AF system was the main design priority and don't feature adequate manual focus aids. I would put the S in that group, though I know not that many would agree with me. But I did many tests over the ten years comparing MF vs the AF confirmation dot and the AF function itself and found the AF to be more accurate. I use manual focus all the time on medium and large format without issue, so the issue was not my vision, it was the accuracy of the system. 

Leica themselves admitted that the mirror did not necessarily exactly match the sensor:

"Dear -----

 

Thank you for letting me know. I look forward to hearing about the rings. Among the other issues I mentioned, the focusing screen does not correspond to the AF sensor (so if you focusing with the optical viewfinder, it is misfocused). Is it Leica’s position that that is also in spec? I ask, because I don’t really feel comfortable selling on a camera that I personally do not think works properly…

 

Best, 

Stuart

Dear Stuart,

 

 

 

I received feedback from my colleagues.

 

 

About the viewfinder. I got the confirmation that the viewfinder can be a little bit different to the sensor.

 

Mit freundlichen Gruessen / kind regards"

A difference that has always existed with film cameras, too. And it never really was an issue. The whole broo-haha over AF and AF speed is akin to pixel-peeping. An obsession over a technical micro-issue. Good for marketing. I see photos all the time taken with multi-thousand dollar set-ups that I would be ashamed to show an entry-level photo class.

The Hy6 and Nikon D professional cameras allow the operator to fine-tune the AF to compensate for the difference between the mirror image and the sensor, keeping that adjustment for several lenses.

Taking a few seconds more care in making the image is worth it to me, whether it entails using a tripod or double-checking focus. And blowing a photo because I wasn't careful enough is just part of making pictures. Just another lesson to learn from. I like the Leica S lenses for their "filmic" look, the images have less of what I consider "digital curse" to them. Something I often spend time in post to eliminate. I guess if I were regularly making stupid-big prints shot wide-open extremely focus accuracy would be important. But I would also be in the poorhouse chasing that and printing that big.

Edited August 31 by Pieter12

[tom0511]

I believe manual focus was easier to handle in film times because of the thickness of film.

Slight focus error seem to show up more clear with digital, and specially if you shoot high resolution.

AF inaccurancies are one of the reasons I dont use my S much any more. The other one is that today I find IBIS really usefull, specially for high resolution sensors. Great to be able to keep ISO low.

While I like the XCD system and my Hassy x2d, I must say  that the lenses dont blow me away like the S-lenses did one day. Specially vignetting is quite visible with many of the xcd lenses ( I often like to shoot at wider f-stops). For me they dont have to make an mirrorless S4 with new lenses. Just put a new sensor with better phase-AF in the S3, add usb-C, and leave the rest as it is. 

[ben446]

Just an observation. With bright, back lit portraits the S 007 & S3 AF seems to really struggle (searching.)  If you can get a little light on the subject's eye with a modeling light, reflector etc..., the AF is pretty good.

Edited September 15 by ben446