Nidelva river through Trondheim Norway

Nidelva river through Trondheim Norway
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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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2k views

Is it really better to not half-press to focus with the Fujifilm X-Pro 1?

Fujifilm's new camera uses contrast-detect autofocus, and the current Internet hand-wringing is over whether this is a horrible critical flaw or not. As often happens in such discussion, a bit of ...
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0answers
295 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?
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1answer
202 views

Nikon D750 + Nikkor 18-35mm - How to enable full autofocus?

I recently got this powerful duet (before I had Pentax K-r), sadly I can call myself a total beginner even I used dslr previously... as I used it with auto mode. However I am learning slowly now, but ...
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1answer
67 views

Bad focus. Is it me or my body (D7000)?

So I have a D7000. Grey market, which I didn't find out until after I had to send it in to get serviced. And it's never felt as...sharp as it should be. I always assumed it was just me. I am going on ...
0
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1answer
140 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 ...
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2answers
111 views

Nikon focus and recompose: identifying behaviour on different models

My Nikon D3000 refuses to take a picture if I focus and recompose with the AE-L/AF-L button set to "AF ON". (The focus point is on an out-of-focus part of the image after I recompose, so the shutter ...
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2answers
2k views

Do separate autofocus motors exist for entry level Nikon DSLRs?

I have a Nikon D3200, which doesn't have an autofocus motor. Therefore, I'm mostly deterred by lenses that don't have focus motors in them. But the ones that do have it are much more expensive. Take ...
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4answers
18k views

Is the lack of AF Motor on the Nikon D5100 an important factor?

I had made up mind on purchasing a Nikon D5100 during the holidays but only yesterday I realized that it doesn't have a AF motor with it. This is forcing me to change to Canon 550D which is in the ...
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1answer
377 views

At which lux level do the Nikon 1 cameras switch from PDAF to contrast-detection?

The Nikon 1 cameras are famous for being able to track focus with their on sensor PDAF. But the story goes that if light is low, it will switch to contrast-detect only and will not track focus as ...
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3answers
7k views

Do I use the camera or lens switch to change between auto and manual focus?

I own Nikon D7000 with 18-105mm lens. I am bit confused how the auto focus and manual focus switching works, particularly with my gear. The confusing part is both the camera and lens have an A-M ...
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0answers
45 views

How can I increase my compact camera's suboptimal autofocus accuracy?

I own a Canon G1X compact camera which is quite good in my expectations, except that I cannot really be confident in its autofocus accuracy especially in non-optimal light conditions. Manual focus is ...
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1answer
55 views

How do I enable back-button AF on the 760D

I have an EOS 760D (recently upgraded from a 30D - yay!), and I'm can't find the custom function that allows you to use back-button AF. Does the 760D have this feature at all or has it been omitted? ...
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2answers
64 views

How can I improve my soft-focus shots out of a moving vehicle?

I was shooting with a shutter speed of 1/4000, f/7, ISO 800, using a 70-300mm telephoto lens. I have been shooting through the windshield of my SUV. Is there a filter I can use to help me get better ...
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0answers
61 views

Difference of auto-focus motor?

What is the difference of ultrasonic motor, stepper motor, and electromagnetic drive? Which one of these are lens-based or screwdrive? What are the advantages of lens-based servo over screwdrive and ...
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1answer
61 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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4answers
63k views

What is back-focusing?

What is back-focusing? Is it something I need to be worried about, or can I just live with it? How can I tell if my camera/lens is sufferring from it?
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1answer
296 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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2answers
72 views

How do I disable autofocus on my Nikon with a Sigma 10-20, which has no manual focus switch?

Just purchased a Sigma 10-20 f/4-5.6 DC HSM lens. In attempting to capture astrophotography, the lens continuously tries to find a focal point in the sky, and doesn't. So I attempt to turn it to ...
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4answers
2k views

Why would my Tamron lens auto focus stop working?

I purchased a Tamron 70-300 mm lens for my Nikon d5300 a few days back. Its autofocus worked perfectly. But now it doesn't work at all. I am a beginner and I don't know much about it. Why would it ...
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4answers
309 views

Why does holding the focus and recomposing also affect the brightness of my photo?

Let's say I try to take a picture of the following scene: a nice, blue river on the bottom and a solid, grey building in the middle. It is a sunny day and I am in a large distance, so both "objects" ...
2
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2answers
178 views

What is the best focus setting for a group photo in manual mode?

I have a Canon 5D Mark III. I understand the depth of field issues taking group photographs at a wedding, but I am concerned the guests at the extremities might be less in focus than the centre if I ...
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2answers
169 views

Fast-focusing point and shoot camera?

I mainly take pictures of my grandkids playing, some scenery and birds. I am looking for an autofocus type camera that has a good zoom, one that will shoot quickly in low light situations. I miss a ...
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1answer
95 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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3answers
782 views

What motor gets used if both lens and camera body have a focus motor?

If both a camera body and lens have motorized autofocus, would one be used over the other or would both work in tandem to speed the focus process along?
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4answers
12k views

How do camera body motors compare to in-lens motors for focusing?

What is the difference between using a motor on the camera body and the motor built into lenses? Aside from how both compare in terms of speed, what differences would I notice if I use a body with a ...
0
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1answer
96 views

Why is my D7100's auto focus not working?

Recently my Nikon D7100 has stopped auto focusing. It's with the AF-S 50mm f/1.8G lens (my only lens). Yes, all the switches are set to auto, and I've done a reset. The autofocus assist light doesn't ...
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0answers
43 views

Autofocus not working on AF-S 35mm 1.8 DX with Nikon D3100

I haven't been using my camera very much over the past few months. The few times I've pulled it out, I noticed that the autofocus doesn't work when I put on my 35mm prime. I tested my 55-200mm and ...
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1answer
7k views

Why is my Canon Rebel T3i delayed 10 seconds or more before image capture?

I am brand new to photography and this camera. Had the smaller lens on and the shutter seemed fine. Tried the larger lens (I bought a kit) which was 200M. Played around with settings, also tried the ...
3
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2answers
172 views

How to more effectively stay in focus with a wide aperture (50mm/1.8)?

I've been experimenting with street photography lately and - while I'm getting some decent shots - my biggest pain point is staying in focus. For example: With the following subject, I nailed a ...
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2answers
86 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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1answer
51 views

Focus issue in D810 after repair

Just got my D810 back from Nikon repair for a USB port problem. The camera was reset completely, including all my settings, date, etc. It has the latest firmware. After doing my usual setup, I used ...
2
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3answers
127 views

Why isn't my DSLR focusing accurately on a fast-moving subject?

Here is a photo I took earlier today: I did my best to track him down the hill and fire off as many shots as I could. Some turned out fine and in focus but the better ones like this one didn't. My ...
43
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4answers
24k views

What apertures are required to enable autofocus, including cross-type or high-precision focusing, on Canon DSLR cameras?

This is a follow-up to Why does Canon and Nikon limit or disable autofocus beyond certain f-numbers? I'm doing this to separate the AF aperture requirements from the linked question above. My goal ...
6
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1answer
1k views

Where is the AF sensor located in a DSLR?

As I understand every DSLR has a separate, smaller sensor that handles phase detection focusing. Where is it located? If this location is different for every DSLR, and therefore this broad question ...
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2answers
143 views

Why does a manual focus lens have an autofocus motor?

Can someone explain to me why the Rokinon 24mm lens has a focus motor? Quoting from LensHero's page on the lens: Generic motor built-in focus motor From what I understand, only autofocus lenses ...
0
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2answers
177 views

How important is body microcalibration feature?

I'm considering buying a Canon 760D / Rebel T6S but it lacks autofocus microcalibration. It's an expensive camera and all upper models including the 70D offer it - so is it something that I can ...
0
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1answer
111 views

Autofocus points in Mirrorless Cameras

Some mirrorless camera such as Sony Alpha 6300 has a lot of AF points (425), whereas flagship DSLR like Canon 1DX Mark II "only" has 61 AF points. Nikon D5 has 153 but it is still way lower than this ...
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4answers
2k views

What causes auto-focus “freezing”?

On occasion, the auto-focus system in my camera and/or lens just stops working. I'll be holding down the shutter release halfway and tracking a subject and I can feel/hear the auto-focus system ...
2
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4answers
2k views

How to tell whether a lens has an autofocus motor or not?

I have to buy a lens and I have a Nikon d7000. I want to know which lenses have AF motors and which do not, as the D7000 has an AF motor built into the body. How do I tell whether a lens has a motor ...
7
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1answer
689 views

What is Nano USM and how does it compare to an STM or USM lens?

The Canon EF-S 18-135mm f/3.5-5.6 IS USM has a designation of Nano USM on the lens. What does this mean? What are the advantages of having it vs STM or USM? We have a terminology thread that usually ...
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2answers
177 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 ...
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1answer
230 views

Why did my Canon 1000D stop working in full auto mode, when it still works in P, Av, etc.?

It's my 7th day with my second hand Canon 1000D. But now, it's stopped capturing pictures in full auto, portrait, close-up, landscape, night portrait, sports, and flash off modes when used in ...
0
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1answer
60 views

Nikon Lens: A (Auto-focus) vs. A/M (Auto-focus/Manual)

I have two lenses which are 18-140 VR and 50 1.8G. On the 18-140 VR I got a button showing A and M while on the 50 1.8 I got a button showing A/M and M. I understand that A is for auto-focus and M is ...
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3answers
95 views

Why did my D5500's autofocus stop working?

My Nikon D5500 will no longer autofocus. It is a brand new camera with hardly any use. My neighbor, who has vast experience in photography, attached the macro lens, took a few shots, and then it ...
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3answers
8k views

Why does my Nikon D3100 no longer auto-focus via the viewfinder?

My Nikon D3100 out of the blue cannot focus correctly. It seem the that the focus motor always stops at the end of the run (Infinity) and cannot lock on the target, thus cannot release the shutter. I ...
2
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1answer
57 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 ...
2
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2answers
1k 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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2answers
28k views

How does focus work on mobile phone cameras?

How does focusing work on mobile phone cameras? Aren't their optics simple enough to not have any moving parts whatsoever? If so, how come most smartphones have an auto-focus, and with various ...
2
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2answers
147 views

For those that can afford fancy teleprimes is it preferred to use AF or MF for birds?

Context I'll be using a Nikon 300mm/f4 on my Sony a6000 and seeing what birds I can get with it. The Sony 55-210mm is what I've been using but it lacks the reach and native teleconverters. ...
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1answer
236 views

How do I auto-focus an EOS M when stopped down to kill the ambient?

I'm trying to do take some portraits with two off-camera strobes. I want a dark background, so I'm using a high f-stop and high ISO to kill the ambient, relying on the strobes to light the model. But ...