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by evan-pak

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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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Canon 5D - Focus viewfinder indicators in Manual focus mode

On a Canon 5D MkIII, is there anyway to see the autofocus lock boxes on screen while manually focusing (showing the areas the camera detects as in focus)? This might just be an insane product of my ...
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1answer
288 views

How to get tack sharp portraits with shallow DOF when lacking an AF point where I want to focus?

What is the best way to get tack sharp portraits with shallow depth of field when lacking an auto focus point where I want to focus. I don't want to crop and "focus and recompose" is not an option ...
2
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1answer
216 views

A recently acquired lens will focus automatically, but won't manually, why?

I have recently acquired a Sigma 70-200mm f/2.8 (Canon mount, relatively old), and it focuses perfectly in auto mode, but in manual mode the focus ring simply won't budge at all. What could be causing ...
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2answers
831 views

Is it normal for autofocus to struggle when using a variable ND Filter?

I recently bought a Marumi variable ND filter and I've been testing it on my 24 - 105mm F4 and 70 - 200mm F2.8 Canon lenses. It seems that my lenses have a hard time focusing when the ND filter is ...
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1answer
1k views

How can I make phase-detection AF more accurate with a Canon 650d and 50mm/1.8?

This is what I get pretty much every time when shooting in Live View mode using the Canon 50 1.8: This is what I get when I'm lucky when focusing through the viewfinder: This is what I get when ...
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1answer
2k views

Is back-button autofocus possible on the Nikon D7000?

A while back I asked about the purpose of back-button autofocus and got several answers. The Nikon D7000 lacks the "AF ON" button that's present in some higher-end cameras. Is it possible to use ...
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1answer
420 views

Do AF-S lenses work with bodies with in-built motors?

I have D-5000 body (without AF motor in the body) and two AF-S lenses. If I upgrade my body to more expensive body one with built-in AF motors, will AF-S lenses work (do autofocus) with new body ? ...
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1answer
233 views

Where is the AF-MF switch on a Tamron 70-300mm tele macro lens?

I am beginner. Recently bought a second hand Tamron 70-300mm tele-macro lens (model 572D) for nikon d5200. Its manual says it has AF-MF switch, but there is no switch I can see on it except normal/...
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3answers
207 views

How to overcome auto-focusing problem in event photography?

The biggest issue for event photography I have noticed is camera not getting auto-focus at correct time. The moment you have to capture the camera is still focusing. If it would be landscape ...
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1answer
83 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 ...
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2answers
388 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 ...
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1answer
293 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 ...
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1answer
435 views

What Ever Happened to Hologram AF?

I'm currently using it in my Sony DSC-F828 and I think works very well especially in low light condition. I've read a lot of hypothesis about it but anyone know for sure why modern cameras don't use ...
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1answer
258 views

Why is my ISO so high in auto mode?

New user of a Canon 7D - less than 50 shots taken. Last night, I needed to take a quick picture of something that was on my cell phone with my Canon 7D I propped the phone up against a white pillow ...
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2answers
1k views

EOS 60D manual focus/exposure selection only after half press

The 60D only lets you select exposure compensation (with the round wheel on the camera back) and AF point (using the 8-way button or the AF point selection button, depending on your settings) only ...
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1answer
1k views

Canon T2i doesn't seem to take crisp photos

I've been using my Canon T2i to do portraits for the last year now, and usually have really good luck with it. Most of my shots are up close, and turn out beautiful. However, it seems like when I ...
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1answer
399 views

Is Sigma 50-500mm EX DG HSM lens compatible with a Nikon D90 body?

Aloha, Can anyone tell me if the Sigma 50-500mm EX DG HSM lens (non OS model) is compatible with a Nikon D90 body? I recently purchased this lens on eBay but it seems that the lens will not ...
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1answer
54 views

How can I use AF+MF on Fujinon lenses with hard stop focus rings?

Fujifilm cameras have an AF+MF mode which autofocuses when the shutter button is half-depressed, then lets you correct it using the focus ring. However, some Fuji focus rings have hard stops, so you ...
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1answer
64 views

What are the (dis)advantages of moving the entire lens for focusing vs. only parts of it?

There's a lens adapter available that adapts Leica lenses to Sony mirrorless cameras. It's called TECHART PRO. The key feature is that it allows to use autofocus with the manual lenses. This works by ...
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2answers
169 views

Why doesn't autofocus work after using manual focus for a while on my Nikon DSLR?

I bought a Nikon D3200 DSLR with 18-55 and 70-200mm lens. I was taking photos for week in autofocus mode, where I have to press shutter button halfway to focus. And then I switched to manual, where I ...
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2answers
134 views

How can I turn off auto focus when using the remote with my Nikon D7000?

I have a remote with my D7000 and it's hugely frustrating that it auto focuses when using the remote. The whole reason I want it is for speed and to not move the tripod. I have looked through the ...
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1answer
66 views

Why do phone cameras focus and defocus deliberately while clicking a macro shot?

I've tried this with many phone cameras and almost all of them focused well for macros but only for a moment before they defocus to focus something further behind. If the camera can focus on objects ...
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2answers
267 views

Why are some portion of my landscape shots totally out of focus?

When shooting landscapes, a single image (say 1 of 200) is totally out-of-focus. A typical setup might be: focal distance = 7.1 (x 3.9) f-number: 5 exposure time: 1/800 According to ...
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2answers
82 views

Does half pressing a RS-80N3 trigger autofocus if back-button AF is enabled?

I'm looking to invest in a remote trigger say the RS-80N3 or alike for my Canon DSLRs. I'm using them all with back-button AF enabled (and half press shutter autofocus disabled) and I wonder if half ...
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2answers
217 views

Why does my lens refocus when the f-stop is changed?

I have a prime Sigma f1.4 50mm lens on my Nikon D90 in P mode and focus mode on a set point of the field and notice that when I am using a tripod and change the f-stop that the camera changes the ...
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2answers
225 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 ...
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2answers
1k views

Nikon D5100 intermittent focusing problem

I'm having this intermittent problem that the camera does not want to focus in auto-focus. When this happens I try to switch to manual on the lens, (both 300mm, and 55mm) but the toggle button will ...
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1answer
844 views

Problem with TTL autofocus on Canon 450d - is there a way to adjust?

I have Canon EOS 450D, and it seems, that camera have problem with autofocusing, when i'm looking through optical viewfinder. If I switch camera to liveview - autofocus works correctly, but slow. The ...
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1answer
531 views

autofocus and maximum aperture of 60D [duplicate]

Possible Duplicate: What are the aperture limits for autofocus on Canon DSLR cameras? It is mentioned on page 79 of the EOS 60D manual that the center point AF is twice as accurate at ...
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1answer
3k views

How do I fix a lens with a problem returning to autofocus mode?

I bought a Canon EF 28-105mm f/3.5-4.5 II USM lens for my Canon 350D. It works mostly fine, except after switching from AF to MF, I can't return to AF mode. After I switch MF->AF, the lens doesn't ...
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1answer
8k views

Sony 18-250 or new Tamron 18-270 lens? Which has better autofocus?

I want to buy either Sony 18-250 F3.5-6.3 or the new Tamron 18-270 F3.5-6.3 as a travel lens for Sony A55. I have found good reviews that told me quite something about image quality of these lens. ...
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1answer
58 views

How do I achieve autofocus while zoomed in on a face, if surrounding elements hold more contrast?

I recently bought a new camera, a Panasonic FZ1000, and noticed on more than one occasion when I was photographing my wife in a posed situation, and I choose to zoom in a little for the shot, the ...
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2answers
374 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 ...
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1answer
355 views

Circular Polarization and Passive autofocus [duplicate]

Couple of weeks ago, I was assigned a homework in one of my Applied Physics master's course. My professor asked to explain why passive autofocus works only with circular polarizers. I am not a very ...
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2answers
2k views

Nikon D60: Autofocus of two AF-S lenses not working anymore after using another lens

I have used my Nikon D60 for about 6 years now, with AF-S DX NIKKOR 18-55mm f/3.5-5.6G, and AF-S 55-200mm Nikkor f/4-5.6G lens, and the autofocus has been working fine this entire time. However, I ...
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6answers
725 views

Is it normal for autofocus to produce blurry photos under low light?

I use a Sony NEX-5R. I find that the autofocus often fails during low light, as in produces out of focus photos. Sometimes it's clearly out of focus, and I can see that on the LCD, in which case I ...
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6answers
798 views

What would be the right way to shoot a portrait in a very dark room with flash?

I have several flash units. Both the shoe-mount type and the "studio" type. The portrait has to be taken in a room that happens to not have windows. It is always dark in there. I can bring a light ...
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2answers
512 views

Is there a way to use phase detection AF with live view on a Canon EOS camera?

On any of the EOS xx(x)D model that has the live view function, can the camera make focus using the AF collimators (instead of using contrast detection), as it's possible on the old Nikon D300 ? If ...
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4answers
3k views

What low-cost ultra-wide angle DX lens will autofocus on my Nikon D5000?

I need a wide angle lens for low-light/club photography with my Nikon D5000. I was going to pick up this one, but then I realized that it won't autofocus on my body. What is the closest equivalent ...
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1answer
355 views

Pictures start in focus then go out of focus?

I was recently shooting some surf after a session with my 7d and Tamron 18-270MM F/3.5-6.3 Di II VC PZD. I started shooting while he was in focus, then as he got to the main part of the maneuver the ...
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4answers
563 views

Autofocus performance of different brands at night

Are there huge differences in the ability to focus in low light between different brands and models? I have a Pentax Kx with a Sigma 30mm 1.4. My problem is, that the camera's autofocus does not work ...
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2answers
255 views

How can lens cause consistent front or back focus?

I can understand body focusing problems, but I can't imagine why lens might cause front or back focus. I have two third party manufacturer lenses for my Nikon: one is front-focusing, the other is back-...
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3answers
353 views

Why is micro 4/3 autofocus so much faster than DSLR live mode focus? [duplicate]

Both a DSLR in live view mode and a micro 4/3 system camera use the main sensor for autofocus. However, on a DSLR it's embarrassingly slow. This can't just be a software thing. How is it that one is ...
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2answers
1k views

Why can't AF-S lens (with broken auto-focus) work with bodies that have build-in motor?

Background: I have a Nikkor 70-300 AF-S G. Somehow, the VR and AF systems stopped working.. It was working perfectly fine, then for 2-3 months it stayed inside the bag, in a wardrobe, without even ...
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3answers
905 views

canon 6d or 5d II for macro?

At the mo I have a 550d and a 60d. my lenses are 17-35 2,8L, 24-80 2,8L, 70-200 2,8L, 100-400 4,5-5,4L sigma 150 2,8 and looking for the canon 50 1,2. The obvious next step is a FF Body. My main ...
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3answers
197 views

Why does my autofocus fail in windy conditions?

When I say windy, I mean inside 100+mph prop-wash, shooting from an open cockpit aircraft. The camera is an Olympus C-765 UltraZoom, which features a retracting zoom lens. It may be that manually ...
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1answer
104 views

Can an off-centre AF point be as sharp/sensitive as a centre AF point?

What is the focal plane for an off centre AF point? Is it the same focal plane as centre AF point? Can off-centre AF point be as sharp focus as the centre AF point? If not, will the sensitivity of ...
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2answers
113 views

How many autofocus points in iPhone 6 camera

I have seen that high-end SLR camera tout the number of autofocus points they have. How many AF points does the iPhone 6 camera have? I have not seen any discussion on it except for "focus pixels".
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13k views

What does the AE lock button do that half-pressing the shutter doesn't?

The Sony A6000 has an AEL button, while Nikon SLRs have an AE/AF lock button. What do these do that half-pressing the shutter to lock focus and exposure, and then recomposing, doesn't? I'm used to the ...
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2answers
120 views

Are extra auto focus points expensive for the manufacturer?

Having a lot of auto focus points is a feature associated with expensive camera bodies. There are of course different types of points like crosstypes and also different sensitivities, but lets ...