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Autofocus is the ability of a camera/lens system to automatically adjust the focus of the lens via a motor attached to the focus group of the lens. Contrast with manual focus.

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1answer
302 views

Are there cameras that autofocus during an exposure?

The origin of this question is related to panning. I was trying to explain why panning is more effective for subjects moving across your FOV at right angles, vs. a subject whose distance to the ...
0
votes
1answer
83 views

Focus specifics in Samsung s5 [duplicate]

Can I take a photo with blurred background with Samsung s5 for a subject far by 2 metres of the lens? and what is the specific distance for manual focus for a 16 megapixel mobile phone lens to take a ...
2
votes
2answers
300 views

Can changing metering mode change focus?

I've Canon 600D and I use the back button to focus and the shutter to meter, I've been using spot metering for over 2 years for now and I understand what's the difference between it and evaluative, I ...
0
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0answers
228 views

Which focus points on the Nikon D750 support f/8?

The Nikon D750 has 11 autofocus points rated up to f/8. Which ones are the f/8 points?
0
votes
1answer
109 views

Canon EOS T2i 35-55 mm lens. Won't autofocus

Actually it WILL autofocus if I force adjust focus by hand beyond subject. It then adjusts itself to focus. If the lens is focused in front of the subject, it will not autofocus. Bad servo in the ...
0
votes
1answer
142 views

Is the Canon 7D compatible with all EF and EF-S lenses? [duplicate]

Are all the lenses compatible with 7d? Especially EF-S? Anyone having a autofocus issue with 55-250mm IS lens?
8
votes
5answers
646 views

How to precisely focus in self-portraiture with very wide aperture?

I've been trying to take some self-portraits, but I often have to struggle with the auto/manual focus. I don't miss by a lot, but I really want sharp focus in the eyes. I'm using a 50mm/1.8 around ...
0
votes
1answer
103 views

Can the Sigma 2x teleconverter be hacked so it will work with the Sigma 50-500mm?

Does the autofocus hack (where you mask off connectors on the teleconverter to make it misreport the aperture) work on sigma 2x teleconverter fitted on Sigma 50-500mm DG lens for Canon cameras?
9
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2answers
8k views

How to enable Canon AF with teleconverter?

Canon DSLR bodies prevent poor auto-focus performance by disabling it completely when the lens reports maximum aperture at chosen focal length smaller than f/5.6. This implies that some lenses will ...
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2answers
237 views

Can over-turning the focus ring break the lens?

I was trying to get low key shots in pretty dark conditions and had my Nikon D7000's 18-105mm VR kit lens in manual focus, to try to get the subject in focus in very low light. In the process, I kept ...
2
votes
1answer
219 views

Nikon 300mm autofocus makes noise and stops working temporarily

I have a Nikon D5100 and a used Nikkor 300mm AF-S f/2.8D IF-ED II, where the two usually work great together. However, if I use autofocus a few times in a row (usually when the change in focus ...
3
votes
4answers
941 views

Will any non-AF lens work on a Nikon camera with built in AF already in the camera body?

I want to purchase a camera with a built in autofocus motor, but I want to know if lenses without autofocus will then focus automatically on that camera body. In other words, can I buy a Nikon camera ...
0
votes
1answer
46 views

Camera body with autofocus [duplicate]

Can I buy a Nikon camera body that already has autofocus, then purchase any non-autofocus Nikon lens and be able autofocus simply from the body itself?
0
votes
1answer
135 views

How do I prevent white box(es) (face detection) from showing up on my Canon EOS 60D?

I use a Canon EOS 60D to shoot a separate angle facing the audience at my Church. It works pretty well, except I have one huge issue. Whenever I point it to the audience, a bunch of white boxes start ...
2
votes
1answer
77 views

5D Autofocus - disable tracking after lock?

I recently got a 5Dmk3 and it's been a really fun toy so far. I'm coming from a Canon 7D, so I'm trying to adjust to the much more complicated autofocus system. I've read the manual and looked around ...
1
vote
1answer
206 views

Why is my Nikon D5100's screen flickering while auto focusing under a streetlight in live view?

Tonight when I took a photo, I found that a horizontal line going upwards in live view while auto focusing. What would cause this?
0
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0answers
102 views

Apertures required to enable autofocus on Rebel T6s/T6i in Live View?

Your article "What apertures are required to enable autofocus, including cross-type or high-precision focusing, on Canon DSLR cameras?" is most useful. Would the new Canon autofocus technology, in the ...
5
votes
3answers
477 views

Do I need a better Camera or do I need to learn how to use the one I have?

Read some of the old questions. I figure that due to my wants you may be able to help me. Let me be clear about what I am doing, what I want to do, and see where we can go from there. I help run ...
0
votes
1answer
155 views

How do prime lens allow variance of focal length when focusing? [duplicate]

If the definition of prime lens says that their focal length is fixed, then how come you can still alter the focal length when focusing? (either MF or AF)
1
vote
1answer
128 views

How can I unlock my manual focus ring?

The manual focus ring on my 18-200mm lens is totaly unmovable. I have tried attaching other lenses to my camera and they work, so I am thinking that there must be an issue with my lens. I have tried ...
26
votes
6answers
6k views

Can I damage the focus system by turning the focus ring when the lens isn't mounted?

I have a couple lenses that don't have an internal focusing system, and whenever I want to put them back in my bag, I turn the focus ring to make the lens shorter. I noticed that when the lens is set ...
0
votes
0answers
37 views

Using motorized lense on a motorized Nikon body [duplicate]

Say I'm using a lens with an AF motor on a Nikon body which also have AF motor. Which one will be active? Is there a way to control it? Thanks
8
votes
1answer
32k views

What is the difference between AI Focus and AI Servo autofocus modes?

Recently I bought a Canon 60D and I am uncertain about when and how to use/activate the AI Focus and AI Servo functions. I understand the One Shot autofocus function for still subjects. You press ...
14
votes
1answer
7k views

What is a focus limiter?

What is a focus limiter and how does it work? What is the advantage of it? For instance Tamron 90/2.8 Macro has a focus limiter. According to the documentation: In the limit position, the Tamron ...
5
votes
1answer
3k views

Why does the IR-Assist beam of Canon Speedlites not get used in AI Servo AF mode?

The IR AF-assist beam on the Canon Speedlites (I have a 430 EX II) doesn't seem to come on when the DSLR (I have the EOS 7D) is in 'AI Servo' AF-mode. It works fine if I'm in one-shot mode (comes on ...
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votes
3answers
251 views

How do you take pictures in a dark room?

I wanted to practice photography with flash so turned off the room lights and tried to take a photo but there is a circle that shows in viewfinder when the camera has locked the focus on something, ...
2
votes
2answers
196 views

Is it possible for increased ISO to improve focusing in low light?

A member of a digital photo forum, to which I subscribe, stated that when she was photographing some badgers at night, the auto focus wouldn't work due to the lack of light. She then said she upped ...
5
votes
4answers
2k views

Are there cheap or DIY focus assist solutions for the Canon 5D?

I want a better autofocus system for low light. Low light auto focus is my biggest bane. I use a 5D so the options are AF on a flash like the 430 or 580. I happen to use the Pocket Wizard TT1 so I ...
3
votes
1answer
1k views

Why is DSLR autofocus much faster than Mirrorless autofocus?

When DSLRs are not using Live View they autofocus much faster than Mirrorless cameras. Why is that? Why can't Mirrorless cameras use the same autofocus mechanism that DSLRs use?
0
votes
1answer
250 views

Do mobile cameras ever vary f stops?

I've been trying to get my head around the camera in my newly-bought Chinese mobile phone. I wonder how focusing actually works in these kind of phones. I imagine that in the standard context of ...
2
votes
2answers
347 views

Why does my Nikon D5100 suddenly have a 30-60 seconds delay before auto focus starts working?

I have a Nikon D5100 with the 18-55 kit lens. It was working fine till a few days ago. The auto focus used to work from the very next second after turning ON the camera. But now the auto focus does ...
2
votes
1answer
557 views

can i transform my manual focus lens into an autofocus lens?

I have a Nikon D3300 camera. And I bought a 55-300mm nikkor lens but this lens is not an autofocus lens, so when shooting I should manually focus and sometimes the photos are blurry. Is there any ...
0
votes
1answer
236 views

camera mobile phone takes pictures at constant focal length if 3.5 mm.supposed to have autofocus and touchfocus [duplicate]

This is a cheap Chinese landvo l200 Android mtk65xx mobile The onlything it keeps Changing is IS0 from 150 to 800 + And exposure time I wondered how can it autofocus and touch Focus when it keeps ...
1
vote
3answers
2k views

How to achieve auto focusing with a non-TTL flash (YN-560 II) in low light situation?

I recently bought a new YN-560 II hotshoe flash but found that it has neither TTL nor assist beam for focusing in low light situations. The problem now is that I'm starting my career as a night ...
0
votes
1answer
2k views

What is the difference between touch focus and autofocus?

I have a cheap Chinese Android phone, a Landvo l200 based on MTK68XX chip. It claims to have a 13MP touch & autofocus camera. I wanted to know how this autofocus feature differs from touch focus ...
9
votes
1answer
494 views

How does autofocus deal with the time to change aperture and raise mirror?

This picture turned out really well: and here Lila is running towards the camera, and the aperture is wide open. I know the AF system uses the phase of light and diffraction to work out when it is ...
5
votes
3answers
4k views

How do I keep my Nikon D5100 from attempting to autofocus with every shutter press?

I have a Nikon D5100 and the auto focus works fairly well most of the time. But there are times when I have a subject in focus and want to fire off multiple shots fairly quickly. I do not need to ...
1
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0answers
68 views

Manual and Autofocus not working on near field with Canon Rebel T3

I dropped my camera on a tile floor the other day and everything appeared fine. My wife tried to take some close up pictures of a gift today and found that the Auto Focus wouldn't work on close field ...
2
votes
2answers
8k views

Why does Nikon D3100 locks Shutter in Autofocus mode?

So I just got this Nikon D3100 Camera. And I am trying to take a picture using autofocus with the kit lens(18-55mm). The system is in Auto mode, AF-A, single frame and the lens A-M switch is on ...
1
vote
1answer
123 views

Where do we focus when shooting cars in a street?

f I just want to put the camera at night at the corner of a street to get long exposure effect of the cars that are moving for their car lights, What is the focus settings I should use? Should I also ...
3
votes
2answers
289 views

lens care: compressing lens without full-time manual focus when camera is off?

The lens manuals for my lenses without "full-time manual focusing" warn not to use the focusing ring when it's in Auto-Focus mode. I assume that even applies when the camera is off, but am I being ...
2
votes
2answers
204 views

Does the Canon AF/MF switch actually do anything on L lenses?

I picked up a second hand 50mm f/1.2L lens recently with not a scratch on it. I've noticed that when the lens is set to MF, the autofocus on the camera (6d) still works. As a workaround I have ...
8
votes
4answers
1k views

Shooting full manual during an event or function

I have been shooting quite a bit of events lately. I do pre-shoot prep on my camera gear and check out the venue ahead of time to evaluate the setting and how the event will run plus light quality to ...
0
votes
2answers
388 views

Does this test chart show that my kit lens front focused?

I just bought me a Nikon D7100 with 18-140 kit lens. When I used focus test chart page 18 to test my camera and lens I got one of following result at 35mm/f4.2. I used Nikon's ViewNX2 to open the raw ...
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0answers
141 views

Contrast detection AF not working?

What are the possible reasons why my Nikon D3300 won't focus properly at all on live view? It works perfectly when using phase detection (or when looking through the viewfinder), but when I start ...
3
votes
2answers
570 views

Nikkor 70-200 2.8 VRII - Does Autofocus <5m really work?

some days ago I daring duck had approached while I was taking photos of her and her friends in a pond. I was testing my new 70-200 2.8 VRII and I was a bit worried about the autofocus while working ...
3
votes
5answers
10k views

Why my “action” shots are blurry even shooting on AF-C, is this a lens or camera limitation?

I'm currently using a Nikon 28-200mm AF-D with my D7000. While trying to take action shots (e.g. my dog running or sports) none of the shots seem to be in focus even on AF-C mode. Would this be a ...
5
votes
5answers
12k views

Missing focus with Canon 50mm 1.8 lens - is it the lens or me?

I purchased a Canon EOS 650D and EF 50mm f/1.8 II lens. Unfortunately, the auto-focus seems to miss focus at f/1.8. I've tried setting it to single-point auto-focus: it is better, but still not good ...
-1
votes
3answers
535 views

Is it true that cameras with larger sensors are more likely to mis-focus under low light?

I use a Sony NEX-5R, and my single biggest problem with the camera is that it often mis-focuses under low light. I shoot a lot of low-light photos, and I work around it by using manual focus. I have ...
1
vote
1answer
279 views

What to do about autofocus problems on a brand new SLR?

I'm having an autofocus problem with my new D5300: I've tested with both the 18-55 kit lens and the 50mm 1.8 AF-S, but it won't always autofocus. I have tested in good light conditions, with different ...