APO Lens AF Performance on the SL3

[helged]

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12 minutes ago, sebben said:

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

I actually think that really fast-focusing Leica lenses may see the light (=being produced) when bodies allow for, lets say, 10-ish fps with AFc. So 1-2 SL-body generations forward in time.

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[LocalHero1953]

18 hours ago, helged said:

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.

I wish you hadn't posted this! I've been trying to ignore this lens for a while now. I have enough portrait lenses and don't need another - my Apo-Summicron-SL 90 is even up for sale (I use the 75mm more). The Sigma looks like it would be a good complement to the Apo-Summicron-SL 75, but it is far too cheap - used versions are available from dealers for around £600. What can I do?

[LocalHero1953]

I'm puzzled by these comments about the slower focusing of the Apo lenses. Is this an issue particularly with the higher resolution sensors on the SL2/SL3? I don't feel constrained by the speed of AF on the SL2-S, and neither I nor my subjects are particularly leisurely - I take portraits quickly, to capture 'unstressed' faces, and my theatre subjects are usually moving. The Summilux-SL 50 is noticeably slow, of course.

This could be just my inexperience with other, faster lenses, but for me it is just not an issue I am concerned with. (I am much more concerned with tracking performance of all Leica AF lenses.)

Edited March 28, 2024 by LocalHero1953

[helged]

2 hours ago, LocalHero1953 said:

I'm puzzled by these comments about the slower focusing of the Apo lenses. Is this an issue particularly with the higher resolution sensors on the SL2/SL3? I don't feel constrained by the speed of AF on the SL2-S, and neither I nor my subjects are particularly leisurely - I take portraits quickly, to capture 'unstressed' faces, and my theatre subjects are usually moving. The Summilux-SL 50 is noticeably slow, of course.

This could be just my inexperience with other, faster lenses, but for me it is just not an issue I am concerned with. (I am much more concerned with tracking performance of all Leica AF lenses.)

For AFs, the APOs work perfectly well. For AFc at 4 or 5 fps (with AFc), Sigma 85, 70-200 and SL24-90 focus faster. The above is based on my experience with our doggie running towards me. 

And actually, SL50Lux is much faster than I would expect based on the previous SL-bodies. It is still slow-ish (ans slower than the APOs), but it is much improved on SL3. This is great since the SL50Lux can deliver special images.

[Planetwide]

2 hours ago, LocalHero1953 said:

I wish you hadn't posted this! I've been trying to ignore this lens for a while now. I have enough portrait lenses and don't need another - my Apo-Summicron-SL 90 is even up for sale (I use the 75mm more). The Sigma looks like it would be a good complement to the Apo-Summicron-SL 75, but it is far too cheap - used versions are available from dealers for around £600. What can I do?

You really should own both the 85mm F1.4 and the 90mm APO. 😁

[LocalHero1953]

37 minutes ago, Planetwide said:

You really should own both the 85mm F1.4 and the 90mm APO. 😁

And there's also the Noctilux 75 for when my ship comes home (or, to bring the phrase up to date, when my meme stock peaks).

Too late for the 90 - it's gone to ffordes for commission sale. 

[Simone_DF]

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2 hours ago, Planetwide said:

You really should own both the 85mm F1.4 and the 90mm APO. 😁

I own the 90 APO and I’m actually considering the 85. I want a gentler lens more geared for portraits. 

[chrismuc]

Sigma 85f1.4 and 65f2 are marvelous on high resolution L-mount cameras … and the new 50f1.2 looks to be so too. Yes and so reasonably priced … and lightweight and small in relation to the speed of the lenses … and wonderful aperture rings 😋.

[LocalHero1953]

I'm not always convinced by the sharper vs softer comparison between the optical designs of, say, the Apo-Summicron-SL 75 vs the Summilux-M 75. I'm sure it's significant, but suspect that it is the extra stop that makes a bigger difference. Shooting a close-up portrait at 75 f/1.4 can mean that the eyes and the lips are in focus and nothing else is. If you wish to convey a romantic sensibility in your portraits, what else would your eyes concentrate on but the eyes and lips? f/1.4 is an erotic aperture 😉.

[LocalHero1953]

On 3/27/2024 at 2:19 PM, helged said:

One aspect to be considered is the colour rendering; this is somewhat different from the SL-APO-Crons.

Can you say a bit more about how you see the difference?

[helged]

I don’t have access to Sigma 85 and SL90 where I am at present, otherwise I would run some twin shots for comparison. I would say that the Sigma - wide open - has a palette with somewhat deduced blues compared to SL90; or that the latter has a more vivid palette. I actually like the Sigma colours, but I dont know the extent to which the Sigma palette blends in a mix with images taken with the SL primes. 

[Dr. G]

3 hours ago, Simone_DF said:

I own the 90 APO and I’m actually considering the 85. I want a gentler lens more geared for portraits. 

This is not going to be received well, but before you do that try a 67mm glimmerglass filter on the 90 for portraits.  

[Dr. G]

2 hours ago, LocalHero1953 said:

I'm not always convinced by the sharper vs softer comparison between the optical designs of, say, the Apo-Summicron-SL 75 vs the Summilux-M 75. I'm sure it's significant, but suspect that it is the extra stop that makes a bigger difference. Shooting a close-up portrait at 75 f/1.4 can mean that the eyes and the lips are in focus and nothing else is. If you wish to convey a romantic sensibility in your portraits, what else would your eyes concentrate on but the eyes and lips? f/1.4 is an erotic aperture 😉.

If 1.4 is erotic, what would you consider .95-1.2?  

[LocalHero1953]

Just now, Dr. G said:

If 1.4 is erotic, what would you consider .95-1.2?  

Too much of a one night stand IMO. I can live with 1.4 in the long term.

[helged]

6 minutes ago, Dr. G said:

This is not going to be received well, but before you do that try a 67mm glimmerglass filter on the 90 for portraits.  

Diversity is good.

[Simone_DF]

1 hour ago, Dr. G said:

This is not going to be received well, but before you do that try a 67mm glimmerglass filter on the 90 for portraits.  

I have a Moment Cinebloom 10 permanently glued on the 90. It’s like the glimmerglass, but with a bit more bloom and haze. I like it for portraits, but occasionally I would like to have the 1.4 effect that a f2 lens won’t provide.

[Stuart Richardson]

On 3/27/2024 at 5:03 AM, 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.

As others mentioned, the APO lenses are moving more glass about. But you are also comparing 35mm and 50mm non-apo small bodied light lenses to a much larger and heavier lens in a longer focal length with shallower depth of field and more distance to travel to focus (all else being equal, elements in a longer lens have to move more to achieve the same change in distance). Lens design is about making compromises. The brief for the APO Summicrons is to have has few aberrations as possible and to be as perfect as possible. They do this at the expense of nimbleness. You are paying for optical performance more than speed. The 35mm and 50mm ASPH lenses were designed to be lightweight and compact lenses that had good focusing for video. That is their design brief. Trying to achieve both at the same time is likely going to result in a lens that is worse than both in their area of specialization.

[pf4eva]

Isn't phase detection only works in AF-C ? If so AF-S probably is not much different than on older SL2 series.

 

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[algrove]

16 hours ago, Dipal said:

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. 

I have only used my APO 90 SL so far of my APO lenses on my SL3. That said it focuses fast enough for me which is instantly the second I hit the joystick to initiate focus. I do not get hunting at all.

IMHO, I believe focusing can be dependent on how the user sets up AF. For example I only use back button focus with MF setup under Focus Mode with Aperture Priority Mode in order to separate focus from exposure and this de-automates the camera. I want to maintain control.

I do not see anyone explaining their setups so this can create huge differences in their SL3's AF reactions.

Edited March 28, 2024 by algrove

[SrMi]

41 minutes ago, pf4eva said:

Isn't phase detection only works in AF-C ? If so AF-S probably is not much different than on older SL2 series.

I assume that AF-S uses hybrid PDAF/CDAF, but I have not seen a conclusive answer by Leica yet.