Photography Stack Exchange
Photography Stack Exchange

Questions tagged [focus]

Focus is the mechanism of converging light from a point light source onto an imaging plane by a lens.

For detailed information on how focus works, see the Imaging Properties section on this Wikipedia article: http://en.wikipedia.org/wiki/Lens_(optics).

A basic diagram of lens focus of points of light in and out of the plane of focus is demonstrated here:

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Any cameras move the sensor instead of lens elements for focus?

All the cameras that I'm aware of move lens elements to obtain focus, although I'm not familiar with the workings of in-phone cameras. It occurred to me this morning that you could also focus by moving the sensor in or out. Just curious if a) it's…
Mark Ransom
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What is focus throw?

This answer to an earlier question of mine about manual focus lenses uses the term "focus throw". Exactly what does that mean? Why do manual focus lenses have more of it than auto focus lenses?
Jan Goyvaerts
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Do 49 focus points mean the camera will focus on 49 different areas at the same time?

I've read a lot but could not find a clear explanation. As I understand, a lens can only focus physically on one point since the focus depends on the physical position of the lens vis-a-vis the sensor. So what is the purpose of these 49 focus points…
Marco
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What is the reference plane used when the minimum focus distance is measured?

Once you know the MFD (minimum focus distance) for a particular lens, is that the distance from the subject to the front of the lens or to the camera sensor?
angel rojas
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How does a camera without hardware autofocus focus?

For e.g. an Apple external Firewire iSight does not have hardware autofocus. So how does it focus? Related questions: Does it focus to infinity? Does that mean it needs a "longer" minimum distance from lens in order for objects to be in focus?
Global nomad
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How can I take a photo through trees but focus on an object behind the trees?

I tried taking a picture of something through some trees but my camera keeps focusing on the trees instead of what is behind the trees. How can I focus on what is behind the tree?
L.Halfpenny
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Programmable cameras that can take multiple shots at different focus settings

To do focus stacking in case of moving subjects, it would be useful to have the ability to preset different focus settings and let the camera take the pictures with the different settings in fast succession. Are there cameras with such a…
Count Iblis
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Nikon D5300 pictures are coming out blurry

When I'm taking pictures in Autofocus on my Nikon d5300 the subject's face comes out blurry. It's not the camera shaking, the shutter speed was on 1/200. It didn't help to zoom in, however, when I zoomed in on half a bench with a little bit of the…
Esther
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How to adjust focus without changing zoom?

I'm taking pictures of a D&D miniature. I'm using an iPhone with an app called VSCO that allows me to change the focus point. I've taped a 10x jeweler's loupe over the camera. My goal is to focus stack the images. However, the images are not…
mark
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Why can I get sharp single person photos but not group photos?

I am just starting out in photography and when I am focusing on one point (like a single person portrait), I can get really sharp photos. However when I am photographing a scene or a group of people, the photos come out blurred, every single time.…
Debbily
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Science Fair Project Relating focus to pinhole size

I am doing a science fair project in which i want to see how the size of a pinhole effects the light diameter, and i would like to also relate this to focus and focal point. How would i do this?
user24494
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Does image quality of the lens affect "focus and recompose" technique?

As I understand it, 'focus and recompose' is often used to ensure the subject is in focus and at the same time composition is right. It has been estimated that some lenses are best in terms of image quality at the center and soft/blurry towards the…
Anil Joseph
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Mavic Pro 1 Infinity focus problem

1 Hello everyone, I am very new to flying drones. I have bought a second hand Mavic Pro 1, and it has this strange issue of focusing at night. Whenever I try to focus to infinity to get a broad DoF, it just doesn't work. I have read every possible…
Dipanjan Pal
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Focus highlighting thumbnails

Is there any software that will analyze the photos in a directory and create thumbnails with the areas most in focus highlighted in color? I know my camera (Sony a99ii) can do this real time. It would be pretty useful, especially when working with…
bruceceng
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set manual focus distance

My nikon D3100 with 18-55 lense set to manual mode. How do i set the focus to 10.5 meters as required for a landscape photo using Hyperfocus calculation. The camera has a range setting for focus but does not show a distance scale. Thanks
chris
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