APO Lens AF Performance on the SL3

[petereprice]

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Hi all - I recently acquired a 75 APO Summicron-SL to add to my 35mm f2 Summicron-SL ASPH (Non APO) and 50mm f2 Summicron-SL ASPH (Non APO).  Although the 75 cron's optical quality is stunning, I find the AF performance to be a big down step compared to these little non APO primes.  Like night and day on the SL3.  I've noticed especially when using some of the newer AF algorithms like the Eye and Face detection, that the 35 and 50 crons are snappy and accurate.  Where as the 75 APO can get a little confused initially and do this hunting fluttering thing, at the very beginning and then snap to focus and then may snap out of focus if the subject moves front to back in their movement.  As long as the subject is not making too many drastic moves, the camera then locks focus.  But I've also experienced the 75 APO having trouble with subjects moving towards me, as opposed to side to side.  Also I've noticed that low light AF performance is a bit of a weak point in this lens.

I'm a bit bummed because I thought that by upgrading to an APO lens, it would perform closer to the non-APO primes, in AF.  But it appears that it not the case and the lens feels a bit unreliable at times, especially in challenging conditions, which is usually where I am.  I went to the store and tested out a 50 APO and it also exhibited similar issues.  I think if I had only ever used the APO's maybe, I would have gotten used to it, but these NON APO primes are really fast, and so now I can't help but feel like the 75 APO is a bit of a downgrade to AF performance.

Has anyone else run into this on the SL3, specifically?  Not so interested in people's experience on the SL2/SL2-S because it's a totally different beast when it comes to AF, so would be curious to hear more from SL3 users with APO lenses who might have also used or currently own the newer non APO 35 and 50 primes for comparison.

[MediaFotografie]

You are absolut right, AF Performance of all APO lenses is not so good on SL3, but also on SL2 bodies. I think the reason is, with APO lenses AF has to move more glas => more wight => slower.

these two new non-APOs have great AF performance

[helged]

51 minutes ago, MediaFotografie said:

You are absolut right, AF Performance of all APO lenses is not so good on SL3, but also on SL2 bodies. I think the reason is, with APO lenses AF has to move more glas => more wight => slower.

these two new non-APOs have great AF performance

+1. Both Sigma and Panasonic have lenses that focus very fast in general, on SL3 included. The SL non-APOs are rebranded+ Panasonic lenses, with fast AF. Personally, I use Sigma 70-200mm f2.8 DG DN and Sigma 85mm f1.8 for their fast (and mostly accurate) AF, also in AFc with 4 (14 bit) or 5 (12 bit) fps on SL3. Actually, I use the Sigma 85mm as a fast AF alternative to SL90.

As a side note: A very fast focusing Leica lens on SL3 is SL24-90. Not a prime clearly, and not a small lens by any means, but fast focusing it is. I think the same holds for SL90-280, but I don’t have that lens anymore.

Edited March 27, 2024 by helged

[Chaemono]

Now it makes sense why the YouTubers were provided the non-APO „SL“ primes when they were invited to Wetzlar and taken to the car museum. 😂

@helgedIt‘s good to know that the SL zooms are fast focusing. That makes them definitely keepers for the SL4.

The question is, what do the colors look like with the SL APO primes. With the 90 APO Summicron-SL at around 16:00 in this review 

https://youtu.be/bPxsUhNmOBc?si=vi8Er5c5mUjBJbx8

the colors can b e made to look stunning. 

 

[petereprice]

6 hours ago, helged said:

. Actually, I use the Sigma 85mm as a fast AF alternative to SL90.

Would you say that the Sigma 85mm has faster and more accurate AF than the SL90 or any other APO?  Also, do you feel it is on par with the Panasonic/rebranded Leica glass?

Edited March 27, 2024 by petereprice

[Planetwide]

Does anybody have the 21mm APO? Does it seem faster? I know its a wide, and therefor much easier to achieve focus, but any comments appreciated.

[Photoworks]

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The Panasonic Lumix S lenses were designed for fast AF, lightweight, minimal focus breathing, and all the same size.

And yes they are faster.

The APO lenses were designed for maximum optical performance. they have linear motors, but they move only a small part of the internal element to focus.

I think only the Summilux-SL is an older design and moves lots of glass.

From what I see the Sigma art 50 1.2 is very fast in focusing on SL3

 

In any case, i don't expect to focus to be faster on SL3, most of the time it uses contrast AF, and when something moves the other modes kick in.

I hope they work on their AF firmware some more.

[MediaFotografie]

vor 20 Minuten schrieb Planetwide:

Does anybody have the 21mm APO? Does it seem faster? I know its a wide, and therefor much easier to achieve focus, but any comments appreciated.

I use the APO-21 with SL3 - it's really a wonderful combination! AF is very similar to the other APO-SL-lenses

Edited March 27, 2024 by MediaFotografie

[Dr. G]

32 minutes ago, Planetwide said:

Does anybody have the 21mm APO? Does it seem faster? I know its a wide, and therefor much easier to achieve focus, but any comments appreciated.

I just got the 21 APO yesterday.  I also have the 35, 50 and 75 APO.  I would concur that the focus speed is on par with the other APO lenses.  

[helged]

47 minutes ago, petereprice said:

Would you say that the Sigma 85mm has faster and more accurate AF than the SL90 or any other APO?  Also, do you feel it is on par with the Panasonic/rebranded Leica glass?

The Sigma 85 is much quicker to focus compared to SL90-APO-Cron. The 85 is a lovely lens; not as bitingly sharp wide open as the SL APO-Crons, but this can also be used as an advantage. Nice and pleasant oof (or bokeh) rendering; much better for my eyes than the SL90Cron. The lens is well corrected, although some weak croma might bee seen in oof highlights; nothing that has bothered me, anyway. One aspect to be considered is the colour rendering; this is somewhat different from the SL-APO-Crons. The latter being very consistent regarding colours. I think you need to see and check in order to decide whether this difference is of importance for you (not a problem for me). All in all, I very much like and appreciate the Sigma 85mm DG DN lens; this is the 90mm-ish lens I go for if AF is of importance.

[BernardC]

1 hour ago, petereprice said:

Would you say that the Sigma 85mm has faster and more accurate AF than the SL90 or any other APO?

More accurate? No.

AF speed is a function of motors in the lens, and of the mass of the focusing group. Accuracy will probably be the same, although arguably a sharper lens can be more accurate.

[LBJ2]

10 hours ago, petereprice said:

Hi all - I recently acquired a 75 APO Summicron-SL to add to my 35mm f2 Summicron-SL ASPH (Non APO) and 50mm f2 Summicron-SL ASPH (Non APO).  Although the 75 cron's optical quality is stunning, I find the AF performance to be a big down step compared to these little non APO primes.  Like night and day on the SL3.  I've noticed especially when using some of the newer AF algorithms like the Eye and Face detection, that the 35 and 50 crons are snappy and accurate.  Where as the 75 APO can get a little confused initially and do this hunting fluttering thing, at the very beginning and then snap to focus and then may snap out of focus if the subject moves front to back in their movement.  As long as the subject is not making too many drastic moves, the camera then locks focus.  But I've also experienced the 75 APO having trouble with subjects moving towards me, as opposed to side to side.  Also I've noticed that low light AF performance is a bit of a weak point in this lens.

I'm a bit bummed because I thought that by upgrading to an APO lens, it would perform closer to the non-APO primes, in AF.  But it appears that it not the case and the lens feels a bit unreliable at times, especially in challenging conditions, which is usually where I am.  I went to the store and tested out a 50 APO and it also exhibited similar issues.  I think if I had only ever used the APO's maybe, I would have gotten used to it, but these NON APO primes are really fast, and so now I can't help but feel like the 75 APO is a bit of a downgrade to AF performance.

Has anyone else run into this on the SL3, specifically?  Not so interested in people's experience on the SL2/SL2-S because it's a totally different beast when it comes to AF, so would be curious to hear more from SL3 users with APO lenses who might have also used or currently own the newer non APO 35 and 50 primes for comparison.

 

9 hours ago, MediaFotografie said:

You are absolut right, AF Performance of all APO lenses is not so good on SL3, but also on SL2 bodies. I think the reason is, with APO lenses AF has to move more glas => more wight => slower.

these two new non-APOs have great AF performance

Thank you for posting your hands-on experience with APO prime AF performance on the SL3. This was a question rolling around on the forums since SL3 was expected to come with PDAF, something I was also interested to know while awaiting SL3 availability. 

[chrismuc]

I own L-mount versions of the Sigma 24f2, 35f2, 65f2 and 85f1.4 lenses. They all have very quick AF motors. I see no reason why the SL f2 Apo Asph lenses should have slower AF than these or the Panasonic f1.8 lenses or the Leica f2 derivates …, other than Leica’s lack of competence in the area of AF electro-mechanics. 

[la1402]

1 hour ago, chrismuc said:

I own L-mount versions of the Sigma 24f2, 35f2, 65f2 and 85f1.4 lenses. They all have very quick AF motors. I see no reason why the SL f2 Apo Asph lenses should have slower AF than these or the Panasonic f1.8 lenses or the Leica f2 derivates …, other than Leica’s lack of competence in the area of AF electro-mechanics. 

Some Friends of Leica claim this is due to much more glass that needs to be moved. But Canon,Nikon and Sony build lenses with lots of glass and fast AF, so I remain unconvinced. 

[Malabito]

APO lenses just focus a bit faster on the sl3, overall its the same experience, dont expect any miracle. If you are okay with the sl2 you will be happier with the sl3, if you cant live with the sl2, the sl3 wont really make much of a difference, you will continue to be unhappy.

[tom0511]

vor einer Stunde schrieb la1402:

Some Friends of Leica claim this is due to much more glass that needs to be moved. But Canon,Nikon and Sony build lenses with lots of glass and fast AF, so I remain unconvinced. 

...

Edited March 27, 2024 by tom0511

[Chuck Albertson]

14 hours ago, MediaFotografie said:

You are absolut right, AF Performance of all APO lenses is not so good on SL3, but also on SL2 bodies. I think the reason is, with APO lenses AF has to move more glas => more wight => slower.

these two new non-APOs have great AF performance

The SLAPO Summicrons *contain* a lot of heavy glass, but only *move* two tiny lenses to focus.

[Dipal]

22 hours ago, petereprice said:

Hi all - I recently acquired a 75 APO Summicron-SL to add to my 35mm f2 Summicron-SL ASPH (Non APO) and 50mm f2 Summicron-SL ASPH (Non APO).  Although the 75 cron's optical quality is stunning, I find the AF performance to be a big down step compared to these little non APO primes.  Like night and day on the SL3.  I've noticed especially when using some of the newer AF algorithms like the Eye and Face detection, that the 35 and 50 crons are snappy and accurate.  Where as the 75 APO can get a little confused initially and do this hunting fluttering thing, at the very beginning and then snap to focus and then may snap out of focus if the subject moves front to back in their movement.  As long as the subject is not making too many drastic moves, the camera then locks focus.  But I've also experienced the 75 APO having trouble with subjects moving towards me, as opposed to side to side.  Also I've noticed that low light AF performance is a bit of a weak point in this lens.

I'm a bit bummed because I thought that by upgrading to an APO lens, it would perform closer to the non-APO primes, in AF.  But it appears that it not the case and the lens feels a bit unreliable at times, especially in challenging conditions, which is usually where I am.  I went to the store and tested out a 50 APO and it also exhibited similar issues.  I think if I had only ever used the APO's maybe, I would have gotten used to it, but these NON APO primes are really fast, and so now I can't help but feel like the 75 APO is a bit of a downgrade to AF performance.

Has anyone else run into this on the SL3, specifically?  Not so interested in people's experience on the SL2/SL2-S because it's a totally different beast when it comes to AF, so would be curious to hear more from SL3 users with APO lenses who might have also used or currently own the newer non APO 35 and 50 primes for comparison.

I can confirm this is true. The 75 and the 90 APO hunt quite a bit. This is on AF-S based on my testing. The AF is really not a good experience with these lenses. 

I am yet to try with the 35/50 APO but I definitely noticed less than smooth AF performance.  I haven't tried AF-C for moving subjects so cannot comment on that. 

[MediaFotografie]

to be honest: Who needs these APO lenses? They are heavy. Large. Slow (f2 only). AF is really slow. Expensive. Everything seems to be bad.

But wait! There is one more thing. When I'm looking at my pictures shot with such a "bad" lens often I'm simply speechless and fascinated seeing the image quality with these lenses (I'm using 21/35/90).

Yesterday I shoot some indoors with APO-21, and there are "portraits" in low light which are simply fascinating.

Have good light!!!

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Hallo,

Look here: Leica L-Mount

[sebben]

Who knows, maybe Leica will rerelease the lenses in a MKII version that is optimised for phase detect.