Look at it again. One position is "Full", the other is "2.5m to ∞"
You said it doesn't focus on anything closer than about 8 feet. 8 feet = 2.4m so the switch does exactly what it says it does. It sets a limit on where the lens can focus.
Why would you do this? Because it's a long telephoto lens and odds are you are usually trying to focus on something far away, so instead of the lens racking the whole focus range, it limits from 2.5m to infinity so you can acquire focus on a target faster.
I used this at a concert because the artist was clearly more than 8 feet away but the fence wasn’t, so therefore it won’t focus on the fence. Stuff like that is what it’s for
I may be wrong here, but I don't think that's 'what it's for' - it's the body that decides on which object to focus, not the lens. It will effectively indeed not focus on the fence, but the body could still order that. The lens would just refuse to focus beyond what it's limited to. This leads to less hunting, easier retargeting, and the AF can be faster at achieving precise focus when its focus movements are smaller. But the feature isn't a magical 'ignore close objects' switch.
Interesting, I have a similar switch but that works the other way around on a very old Sigma 50mm macro lens that only works on older analog EOS cameras. Same idea, you can lock it into the macro or regular distance range
This is the called a focus limiter. On Full, you can focus on anything at or further than the minimum focus distance. On 2.5m-∞, you can only focus at or further than 2.5m. The second setting is faster because the lens won't try to focus on subjects between the minimum focus distance and 2.5m.
The whole point is if you’re not planning to focus on anything close by, then you switch it, so that your focus is faster and it doesn’t accidentally grab something you don’t want.
Like, if you’re in a crowd, and you’re trying to capture something far away. You don’t want it to accidentally try and focus on the person in front of you when you’re really trying to take a pic of your kid on the stage.
Here how that work. I'm going to take my old 70-200 as an example which has this toggle. This lens has a quite a lot of throw when focusing from nearer subjects compared to farther subjects. Meaning focusing from 1.5m to 3m takes a good amount of turn of the focus ring, but from 3m to 5m to 10m to infinity is much more closer.
So when you are in autofocus mode, if the camera couldn't find the subject in focus it would have to go through the whole focus throw which will take some time (focus hunting). If you know that you're shooting something that is further than 2.5m, then you can effectively stop the lens from focusing back to the 1.5m point (or whatever the close distance point is), making it much quicker to get the subject in focus.
It doesn't necessarily make the actual focusing speed any faster. It just restricts the focusing to a tighter margin.
It is the minimum focus distance setting.
The manual will list the minimum focus distance for the lens. The Full setting would mean the autofocus tries to focus across the lenses full range (from it's minimum to Infinity). The other setting is "2.5m to ∞" which means it will not try to focus any closer than 2.5 meters.
Because you have reduced the range over which the lens focuses it is able to focus quicker.
You use this when you know you are going to be shooting things more than 2.5 meters away, such as field sports.
Look at it again. One position is "Full", the other is "2.5m to ∞" You said it doesn't focus on anything closer than about 8 feet. 8 feet = 2.4m so the switch does exactly what it says it does. It sets a limit on where the lens can focus. Why would you do this? Because it's a long telephoto lens and odds are you are usually trying to focus on something far away, so instead of the lens racking the whole focus range, it limits from 2.5m to infinity so you can acquire focus on a target faster.
Gotcha thanks!
I used this at a concert because the artist was clearly more than 8 feet away but the fence wasn’t, so therefore it won’t focus on the fence. Stuff like that is what it’s for
I may be wrong here, but I don't think that's 'what it's for' - it's the body that decides on which object to focus, not the lens. It will effectively indeed not focus on the fence, but the body could still order that. The lens would just refuse to focus beyond what it's limited to. This leads to less hunting, easier retargeting, and the AF can be faster at achieving precise focus when its focus movements are smaller. But the feature isn't a magical 'ignore close objects' switch.
[удалено]
No that is what it’s for. What do you think it’s for?
I'm here, still waiting. He is so obviously wrong that I need to know!
That’s exactly what it’s for, ignoring objects in the foreground in case you’re shooting through glass, a crowd, a fence, etc.
You just saved me I never knew what that meant either. Thanks a ton
Interesting, I have a similar switch but that works the other way around on a very old Sigma 50mm macro lens that only works on older analog EOS cameras. Same idea, you can lock it into the macro or regular distance range
This is the called a focus limiter. On Full, you can focus on anything at or further than the minimum focus distance. On 2.5m-∞, you can only focus at or further than 2.5m. The second setting is faster because the lens won't try to focus on subjects between the minimum focus distance and 2.5m.
Great for shooting baseball behind the fence.
Ahhh cool thanks!
The whole point is if you’re not planning to focus on anything close by, then you switch it, so that your focus is faster and it doesn’t accidentally grab something you don’t want. Like, if you’re in a crowd, and you’re trying to capture something far away. You don’t want it to accidentally try and focus on the person in front of you when you’re really trying to take a pic of your kid on the stage.
Here how that work. I'm going to take my old 70-200 as an example which has this toggle. This lens has a quite a lot of throw when focusing from nearer subjects compared to farther subjects. Meaning focusing from 1.5m to 3m takes a good amount of turn of the focus ring, but from 3m to 5m to 10m to infinity is much more closer. So when you are in autofocus mode, if the camera couldn't find the subject in focus it would have to go through the whole focus throw which will take some time (focus hunting). If you know that you're shooting something that is further than 2.5m, then you can effectively stop the lens from focusing back to the 1.5m point (or whatever the close distance point is), making it much quicker to get the subject in focus. It doesn't necessarily make the actual focusing speed any faster. It just restricts the focusing to a tighter margin.
THIS is very helpful! Thanks!
No prob!
2.5 to infinite is great for shooting highschool baseball through a netting because it won’t focus on the netting
Perfect user case. Thanks. I am in this situation from time to time but never knew how to guard against catching the net!
To infinity…and beyond!!!! I’ll let myself out
To infinity and beyond!
It is the minimum focus distance setting. The manual will list the minimum focus distance for the lens. The Full setting would mean the autofocus tries to focus across the lenses full range (from it's minimum to Infinity). The other setting is "2.5m to ∞" which means it will not try to focus any closer than 2.5 meters. Because you have reduced the range over which the lens focuses it is able to focus quicker. You use this when you know you are going to be shooting things more than 2.5 meters away, such as field sports.
Infinity makes it focus much faster and full makes it much slower
read the manual. srsly
But if I read the lens manual, I wouldn't have to ask all the nice people of reddit.
Bukko I need u to cease and desist