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Archive 2021Strange AF pumping on 35 GM 1.4 and A7R4
p.3 #2Strange AF pumping on 35 GM 1.4 and A7R4
No reply in three days... Unfortunately I can't be to any help either. I wonder what's wrong here.
The only Sony MIILC I have these days is the A7C. With the 35Gm mounted and trying to do what you show us in the video I fail. The camera locks focus, AF-S works fine and AF-C even better, in most cases. When pointing it at a radiator with no sharp vertical line but shadows it most often focuses correctly. Trying different positions of the radiator it will finally miss focus. Then the combination tries once in each direction and eventually stops focusing showing a reddish focusing area frame.
Perhaps the focusing tech is different (the A/C seem to work with phase detection also in AF-S), the algorithms different or everything is different.
However, I wouldn't worry about a camera not being able to focus at this specific target. Does it work when doing more "normal" things?
The only Sony MIILC I have these days is the A7C. With the 35Gm mounted and trying to do what you show us in the video I fail. The camera locks focus, AF-S works fine and AF-C even better, in most cases. When pointing it at a radiator with no sharp vertical line but shadows it most often focuses correctly. Trying different positions of the radiator it will finally miss focus. Then the combination tries once in each direction and eventually stops focusing showing a reddish focusing area frame.
Perhaps the focusing tech is different (the A/C seem to work with phase detection also in AF-S), the algorithms different or everything is different.
However, I wouldn't worry about a camera not being able to focus at this specific target. Does it work when doing more "normal" things?
May 22, 2021 at 11:33 AM
p.3 #3Strange AF pumping on 35 GM 1.4 and A7R4
No problem with normal things, or strong vertical lines. But I'm not paying for a premium lens with a worse AF behaviour than my smartphone. I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy.
My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
May 22, 2021 at 02:55 PM
p.3 #4Strange AF pumping on 35 GM 1.4 and A7R4
obwohl wrote:
No problem with normal things, or strong vertical lines. But I'm not paying for a premium lens with a worse AF behaviour than my smartphone. I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy.
My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
"I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy."
Did you check it with portraits instead of photographing things with not much contrast and a lot of lines? Is that the usual subject you want to photograph? All I can say is that the 35GM + Sony cams (including A7riv) works great, esp. with portraits.
No problem with normal things, or strong vertical lines. But I'm not paying for a premium lens with a worse AF behaviour than my smartphone. I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy.
My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
"I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy."
Did you check it with portraits instead of photographing things with not much contrast and a lot of lines? Is that the usual subject you want to photograph? All I can say is that the 35GM + Sony cams (including A7riv) works great, esp. with portraits.
May 22, 2021 at 04:36 PM
p.3 #5Strange AF pumping on 35 GM 1.4 and A7R4
I will not invite any model to a shooting when technical details are not clear. For a pro-grade lens the behaviour is a very poor performance and I hope my replacement will do better. I'm paying also for reliability - and this is not fulfilled with my lens.
May 22, 2021 at 05:32 PM
p.3 #6Strange AF pumping on 35 GM 1.4 and A7R4
Yes. I had a second look at the last video. The first time I turned it off before you aimed at the heat meter.
The A7C and the 35GM would have managed that without hickups.
If it is the camera, the lens or a firmware thing causing this I can't say but I fully understand you are bummed.
The A7C and the 35GM would have managed that without hickups.
If it is the camera, the lens or a firmware thing causing this I can't say but I fully understand you are bummed.
May 23, 2021 at 11:51 AM
p.3 #7Strange AF pumping on 35 GM 1.4 and A7R4
j4nu wrote:
I'd even venture to say that if you've bought into the Sony ecosystem to use AF-S, you don't really know what you're doing
... Of course, there are exceptions but still...
This is true for me as well, but for my 24 gm, I sometimes have focus pumping that I have on no other lenses. Afs solves the issue, as does sometimes making the focus area larger to more easily find contrast. It is a quirk with that lens. This might be similar.
I'd even venture to say that if you've bought into the Sony ecosystem to use AF-S, you don't really know what you're doing
... Of course, there are exceptions but still...This is true for me as well, but for my 24 gm, I sometimes have focus pumping that I have on no other lenses. Afs solves the issue, as does sometimes making the focus area larger to more easily find contrast. It is a quirk with that lens. This might be similar.
May 23, 2021 at 01:37 PM
p.3 #8Strange AF pumping on 35 GM 1.4 and A7R4
shadow9d9 wrote:
... Of course, there are exceptions but still...This is true for me as well, but for my 24 gm, I sometimes have focus pumping that I have on no other lenses. Afs solves the issue, as does sometimes making the focus area larger to more easily find contrast. It is a quirk with that lens. This might be similar.
Yes, for my 24GM I use AF-S with aperture closed down to around f6.3 and further... otherwise I get unreliable focus in AF-C.
My quoted comment was mostly about how great Sony's AF-C is, so that completely disregarding it you lose one of the biggest advantages of the system...
j4nu wrote
I'd even venture to say that if you've bought into the Sony ecosystem to use AF-S, you don't really know what you're doing ... Of course, there are exceptions but still...Yes, for my 24GM I use AF-S with aperture closed down to around f6.3 and further... otherwise I get unreliable focus in AF-C.
My quoted comment was mostly about how great Sony's AF-C is, so that completely disregarding it you lose one of the biggest advantages of the system...
May 23, 2021 at 02:05 PM
p.3 #9Strange AF pumping on 35 GM 1.4 and A7R4
obwohl wrote:
I will not invite any model to a shooting when technical details are not clear. For a pro-grade lens the behaviour is a very poor performance and I hope my replacement will do better. I'm paying also for reliability - and this is not fulfilled with my lens.
You don't need to invite a model. Just go before a mirror and use eye-af and your lcd, or use your wife, gf, mother etc.
Sometimes a new lens/body combination can have issues and a factory reset can help wonders. I would try that, helped me in the past, too (I guess firmware is up to date?).
We have two 35GMs and on our a7riv both work as intended. I only use AFC, by the way. It only pumps when focus points are used outside the AFC focus area or below MFD.
I will not invite any model to a shooting when technical details are not clear. For a pro-grade lens the behaviour is a very poor performance and I hope my replacement will do better. I'm paying also for reliability - and this is not fulfilled with my lens.
You don't need to invite a model. Just go before a mirror and use eye-af and your lcd, or use your wife, gf, mother etc.
Sometimes a new lens/body combination can have issues and a factory reset can help wonders. I would try that, helped me in the past, too (I guess firmware is up to date?).
We have two 35GMs and on our a7riv both work as intended. I only use AFC, by the way. It only pumps when focus points are used outside the AFC focus area or below MFD.
May 23, 2021 at 03:27 PM
p.3 #10Strange AF pumping on 35 GM 1.4 and A7R4
shadow9d9 wrote:
... Of course, there are exceptions but still...This is true for me as well, but for my 24 gm, I sometimes have focus pumping that I have on no other lenses. Afs solves the issue, as does sometimes making the focus area larger to more easily find contrast. It is a quirk with that lens. This might be similar.
Interesting, can't confirm that. We use the 24GM on the dance floor often and it focuses as intended.
In very low light I only had some pumping with the 50/1.4 on the A7r3, where sensitivity wasn't enough. Putting it on the A9 and it focused as intended. But that was only for very low light conditions.
j4nu wrote
I'd even venture to say that if you've bought into the Sony ecosystem to use AF-S, you don't really know what you're doing ... Of course, there are exceptions but still...Interesting, can't confirm that. We use the 24GM on the dance floor often and it focuses as intended.
In very low light I only had some pumping with the 50/1.4 on the A7r3, where sensitivity wasn't enough. Putting it on the A9 and it focused as intended. But that was only for very low light conditions.
May 23, 2021 at 03:32 PM
p.3 #11Strange AF pumping on 35 GM 1.4 and A7R4
obwohl wrote:
No problem with normal things, or strong vertical lines. But I'm not paying for a premium lens with a worse AF behaviour than my smartphone. I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy.
My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
1. It wobbles because you’ve hit an edge case for on sensor phase detect autofocus. A bunch of purely vertical lines with soft contours of light going across them, and an autofocus box big enough that ANYTHING in that zone is in focus, such that it will just keep searching for something to focus on. You aren’t even using object tracking or some mode in which the camera would attempt to do anything smart. You’ve just set a box within which the camera will continue to search for the area of highest contrast, which will continuously change based on where the lens is focusing. The reason it “wobbles” is because the lens focuses so quickly. On other, slower lenses, you’d see something much less interesting as they focus more slowly. Your lens is just being told by the camera to refocus continuously to a slightly different position because of the specifically tricky situation for Sony PDAF.
2. Your smartphone has so much depth of field that “in focus” likely doesn’t really mean anything. Everything on that wall will be in focus. Secondly, if you set your camera to AF-S then it too would focus the same way that your phone does.
As many others have suggested, perhaps you should attempt to take an actual photograph. I’d advise you to google “Sony on sensor pdaf how does it work” and “Sony on sensor pdaf limitations” to improve your knowledge base so you have a better understanding of why these situations would arise.
May 23, 2021 at 04:29 PM
p.3 #12Strange AF pumping on 35 GM 1.4 and A7R4
FWIW I had the same issue with a 12-24mm GM on an A7R3. I even sent it back to B&H to be repaired. They returned it to me saying nothing was wrong with the lens. It had the same issue as before. So, I returned it.
May 23, 2021 at 04:37 PM
p.3 #13Strange AF pumping on 35 GM 1.4 and A7R4
Jesse Evans wrote:
obwohl wrote
No problem with normal things, or strong vertical lines. But I'm not paying for a premium lens with a worse AF behaviour than my smartphone. I want to shoot lots of portraits in psychological complex environments, so I cannot afford to have a lens which is bitchy.My main concerns are:
a) why does it wobble at all (that's not how it should behave, right? red sign for failed focus would be better)
b) my smartphone (S20+) is able to focus on that heater
c) it does not even focus on the vertical heating-meter as you can see
I'm replacing that lens.
Ding ding ding!
May 23, 2021 at 04:56 PM
p.3 #14Strange AF pumping on 35 GM 1.4 and A7R4
I took quite a lot photographs. I'm not very impressed because it failed quite often to detect the face or it showed strange pumping - normal light and the face being 2 m away. Either my A7Riv is crap or the new lens - I'm returning it for a new one.
May 23, 2021 at 06:19 PM
p.3 #15Strange AF pumping on 35 GM 1.4 and A7R4
Glad to report no "pumping" on my 35mm GM and A7r4. Love the lens so far.
May 31, 2021 at 12:32 PM
p.3 #16Strange AF pumping on 35 GM 1.4 and A7R4
obwohl wrote:
I took quite a lot photographs. I'm not very impressed because it failed quite often to detect the face or it showed strange pumping - normal light and the face being 2 m away. Either my A7Riv is crap or the new lens - I'm returning it for a new one.
This is two months after your original post. You're only going to return it now, after more than two months? And the store will still take it back after two months?
I'd call that a used lens.
I took quite a lot photographs. I'm not very impressed because it failed quite often to detect the face or it showed strange pumping - normal light and the face being 2 m away. Either my A7Riv is crap or the new lens - I'm returning it for a new one.
This is two months after your original post. You're only going to return it now, after more than two months? And the store will still take it back after two months?
I'd call that a used lens.
May 31, 2021 at 12:38 PM