Samyang Lens Manager AF options

Started 9 months ago | Discussions
Kiril Karaatanasov Senior Member • Posts: 2,203
Samyang Lens Manager AF options

I got the Samayng lens station to update the firmware.

My 24/1.8 occasionally back focuses when shooting portraits. It is a bit of weird behavior. When I test the lens it seems to work well. When I shoot portraits the results are not as great as the focus is sometimes on the background despite the eye AF point being placed where needed.

I wanted to see if the lens station can help.

I am quite confused by the options in the lens manager. Can anyone point me to a resource explaining the 4 sliders? How do I use them to correct my lens?

Samyang manual only explains a single slider and even that is quite scant "AF can be adjusted by ±4."

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Rol Lei Nut Veteran Member • Posts: 5,971
Re: Samyang Lens Manager AF options
2

Until someone better informed answers, I'd guess that the adjustments are for 4 different focusing distances. Starting from the bottom; INFinty, 40x the FL (=96cm, 40x on a UWA is pretty close!), 20x the FL (48 cm) and MOD (minimum focusing distance?).

Kiril Karaatanasov wrote:

I got the Samayng lens station to update the firmware.

My 24/1.8 occasionally back focuses when shooting portraits. It is a bit of weird behavior. When I test the lens it seems to work well. When I shoot portraits the results are not as great as the focus is sometimes on the background despite the eye AF point being placed where needed.

I wanted to see if the lens station can help.

I am quite confused by the options in the lens manager. Can anyone point me to a resource explaining the 4 sliders? How do I use them to correct my lens?

Samyang manual only explains a single slider and even that is quite scant "AF can be adjusted by ±4."

TN Args
TN Args Forum Pro • Posts: 10,491
Re: Samyang Lens Manager AF options
2

It is probably MOD= Minimum Operating Distance, then 20x MOD, 40x MOD, and infinity focus adjustments.

I really doubt that it will be any help for occasional misfocusing.

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OP Kiril Karaatanasov Senior Member • Posts: 2,203
Re: Samyang Lens Manager AF options

Thank you. This makes a lot of sense. I guess it will be hard to tune the lens if it comes to this.

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OP Kiril Karaatanasov Senior Member • Posts: 2,203
Thank you

Thanks for the quick answer.

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SQLGuy
SQLGuy Forum Pro • Posts: 12,012
Re: Samyang Lens Manager AF options

Same behavior with both of your cameras?

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OP Kiril Karaatanasov Senior Member • Posts: 2,203
Samyang 24/1.8 focusing woes.

SQLGuy wrote:

Same behavior with both of your cameras?

Yes.

I did a portrait shoot during the weekend with A7r3. Some of the portraits were of a girl in front of a door and the focus was on the door. I used eye AF in AF-C and it looked fine in the EVF. I only found a few of the photos are soft after downloading to the computer.

Similarly, with A7C I took pictures of my daughter while hiking, and some of the photos had a focus behind her. Again I only found it at home while during the walk AF-C seemed to follow the eyes. A7C is also very smart and if it loses the eyes it typically retains focus on the person.

In both cases, the consequence is that the face is soft. In both cases, I used Eye AF.

I use the Samyang 75/1.8 often too. I never had this issue with it.

I am using 24/1.4, 35/1.8, 55/1.8 from Sony that are similar in size, focal length, and those work great.
Samyang 24/1.8 is great for its compactness and weight. 24mm is one of my favorite focal lengths and I love to have it on A7C. Also, the optics of the 24/1.8 seem sufficiently sharp i.e. not the 24/1.4GM level but very usable.

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SQLGuy
SQLGuy Forum Pro • Posts: 12,012
Re: Samyang 24/1.8 focusing woes.

Kiril Karaatanasov wrote:

SQLGuy wrote:

Same behavior with both of your cameras?

Yes.

I did a portrait shoot during the weekend with A7r3. Some of the portraits were of a girl in front of a door and the focus was on the door. I used eye AF in AF-C and it looked fine in the EVF. I only found a few of the photos are soft after downloading to the computer.

Similarly, with A7C I took pictures of my daughter while hiking, and some of the photos had a focus behind her. Again I only found it at home while during the walk AF-C seemed to follow the eyes. A7C is also very smart and if it loses the eyes it typically retains focus on the person.

In both cases, the consequence is that the face is soft. In both cases, I used Eye AF.

I use the Samyang 75/1.8 often too. I never had this issue with it.

I am using 24/1.4, 35/1.8, 55/1.8 from Sony that are similar in size, focal length, and those work great.
Samyang 24/1.8 is great for its compactness and weight. 24mm is one of my favorite focal lengths and I love to have it on A7C. Also, the optics of the 24/1.8 seem sufficiently sharp i.e. not the 24/1.4GM level but very usable.

Sounds like it would be worth trying to open a support ticket with Samyang.

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Qqphot Regular Member • Posts: 255
Re: Samyang Lens Manager AF options

I've always been confused by how these settings apply on a mirrorless camera.  It seems like the camera should know absolutely whether focus is correct or not based on what's hitting the sensor, so adjusting some behavior of the lens should just cause the camera to command a bit more or less movement to regain on-sensor sharp focus.

I'm sure there's more going on, because I do have lenses where the camera confirms focus but the images miss focus more often than not, but they're 3rd party (Sigma) lenses and I assume that's Sony just being Sony.

SQLGuy
SQLGuy Forum Pro • Posts: 12,012
Re: Samyang Lens Manager AF options

Qqphot wrote:

I've always been confused by how these settings apply on a mirrorless camera. It seems like the camera should know absolutely whether focus is correct or not based on what's hitting the sensor, so adjusting some behavior of the lens should just cause the camera to command a bit more or less movement to regain on-sensor sharp focus.

I'm sure there's more going on, because I do have lenses where the camera confirms focus but the images miss focus more often than not, but they're 3rd party (Sigma) lenses and I assume that's Sony just being Sony.

Most adapters don't support Eye AF on II series cameras at all.

The Metabones does, but only in the center.

This implies that there is some special information the lens needs to provide the camera to allow Eye AF to work. If Samyang isn't providing this quite correctly, or under all situations, then I could see this causing the AF to fall back to some other unexpected acquisition. Since the cameras seem to be still showing the Eye AF focus box, I am not sure this is entirely Samyang's fault, but they are probably under more pressure to fix it than Sony would be.

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