Questions tagged [focus]

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

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18
votes
3answers
6k views

How can a smartphone take pictures of a landscape with everything in focus?

After the announcement of the new Samsung Galaxy S9 with the new camera that changes aperture, I caught myself wondering: if smartphones have such a wide aperture (f/2.8, f/2.2, etc), how are ...
0
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2answers
233 views

Sharp focus photography with APS-C [closed]

So, it happens that I am really passionate about the sharp focus photography, where some points on the picture looks sharper than the usual, just like the example I've attached. My question is: how ...
11
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4answers
2k views

Why does wider aperture make snowflakes look bigger?

Recently I went out to shoot when it was snowing. I was playing around with different aperture sizes and exposure times. What I have noticed that the wider the aperture, the more snow I can capture ...
-1
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1answer
525 views

Focus distance and infinity

When I play with M12 lenses (board lenses. Fixed fl. Aperture) , I can focus them to a distance and they have a certain depth of field. Objects within the Delta of field looks sharp. Can these lenses ...
0
votes
1answer
74 views

Pentax lens focus ring snapping

I have a Pentax DA 35mm lens that was stored in the camera bag for a while. When trying to use it today, I noticed that the focus ring motion is not smooth. It is "snapping" at specific intervals, 3 ...
1
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3answers
207 views

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, ...
2
votes
2answers
317 views

How to tell which image from a set is the most in focus? [duplicate]

I am calibrating the focus on my 35mm film scanner, to do this I am rescanning the same photo repeatedly with different focus configurations and comparing the results to choose the configuration which ...
3
votes
1answer
675 views

Can I keep the 'Constant Preview' feature active during MF assist on my Panasonic Lumix?

I have a Lumix G7, here's the issue I'm in Manual mode, and I have Constant Preview on, so if I modify the aperture, shutter speed, ISO, WB, I see everything correctly in the preview. However, if I ...
2
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1answer
145 views

Does diopter settings change when lens is put on backwards?

One way of doing macro photography on the cheap is to flip the lens backwards I am having issues focusing, the diopter is calibrated but when I flip the lens the focus of taken picture is not the ...
0
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3answers
3k views

Camera Slow To Respond When Trying To Take A Photo | Nikon D5300

I have a Nikon D5300. When I try to take a photo (I reset all settings to factory settings) and hold down the button to focus or just a quick snap, there is a long delay in the camera finishing to ...
4
votes
3answers
228 views

help with moon flares

I recently switched from a cropped sensor, APS-C Sony to a full frame sensor Sony. When I would take pictures of the moon with the cropped sensor, I would get this: 15s, f1.4, ISO 1000. And this is ...
0
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3answers
2k views

Understanding focus distance of Nikon f/1.8D lens with D5600 Camera

I took some sample photos using my Nikon D5600 camera with Nikon f/1.8D lens. I had to set the focus manually since this lens doesn't provide AF with my camera. My Question: The album of my sample ...
3
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4answers
2k views

How can I focus on only part of the scene when there are multiple objects at the same distance?

I just wanted to have the red leaf focus only, and not have the nearby twigs in focus too. How can I achieve that? I locked the focus on the read leaf then move the camera to reposition the scene. ...
0
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2answers
123 views

Does processor affect auto-focus precision?

I am considering purchasing a Canon sl2. I notice that it has the same 9 point 1 cross type auto focus system that has been used for many many years. My current Canon t3 uses this auto-focus system. ...
1
vote
1answer
924 views

How do I force my Canon dSLR (800D) to take a photo?

I noticed when I went out early in the morning to take some landscape photography that sometimes when the image was "dark", the camera would not attempt to take the photo. I tried changing from a ...
0
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2answers
2k views

How can I cause red eye in photos I take with my iPhone 6s?

How do I cause red-eye in my photos? I had no trouble causing red-eye in my old iPhone 4; but having issues with the 6s, even with [right & left] circular polarising filters over the flash and ...
2
votes
4answers
1k views

Do convex lenses make light from different points converge to different points?

I'm starting to study camera and lenses. Most of the sources online introduce you to the concept of convex lenses, with pictures similiar to this: This picture just show you that parallel rays (of ...
12
votes
3answers
2k views

Do convex lenses make parallel light rays of different wavelength converge to different points?

I'm starting to study cameras and lenses. By reading explanations and watching videos on convex lenses, I learnt that they make parallel light rays converge to a single point called the focal point. ...
2
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0answers
92 views

Why does a blurred out background make this photo look like a miniature? [duplicate]

I have this photo before and after being blurred (From Macphun software ad): I dont know about you but for some reason the blurred version almost makes the island look like it is an intricately ...
5
votes
1answer
2k views

Can I use focus point on manual mode?

I just got my first DSLR Canon 6d and Canon 50mm f1.8 lens . Because im begginer on photography i dont know anything but im tring to learn by watching youtube, but there are some questions i have, i ...
1
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1answer
125 views

error on lens or camera?

i brought a brand new d5300 50mm 1.8g and tamron 18-200 about 10 months ago. everything is fine. the camera and the 2 lens. i borrow a d300 for testing. i put 50mm to d300. everythings fine. it ...
1
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1answer
136 views

Getting two subjects sitting across the table in focus

Hoping to get some tips on photographing two subjects sitting across each other a table (the table is maybe 2 feet long). They’ll be at the same distance from the camera just a few feet away from each ...
49
votes
3answers
10k views

Why do photo cameras lose focus when you zoom, when movie or TV cameras keep it?

In photo cameras, i.e. (D)SLRs, digital cameras, etc., when you focus on an object and then you zoom (in or out), the object gets out of focus. On the other hand, in movie or TV cameras, the focus is ...
0
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3answers
103 views

Focus of lens dropoff from center to ends [duplicate]

I have come across a couple lens manufacturers that mention that when a lens is focused such that the center of the FOV is well focused, the extreme ends of the FOV will be slightly defocused. What ...
2
votes
3answers
3k views

Why can't my dSLR take close-up photos?

I am relatively new to DSLR cameras, so I apologize for any potential ignorance. Since I have been using my Canon T3i, every time I attempt to take a close-up photo, the camera does not auto adjust ...
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3answers
281 views

Is focal length internal or external? [duplicate]

I just wanted to check because I've encountered various distinctly different assertions. I was originally taught that focal length referred to the optimum distance from subject| ←→|lens, where ...
-2
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3answers
170 views

Having trouble getting my entire frame in focus! [duplicate]

I'm shooting a banquet room restaurant for website pitures and am having trouble getting the enitre room in focus. The shots Ive taken theres one set table in focus and the glasses and decor on the ...
1
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0answers
53 views

auto focus in nikon d7000

I have a Nikon D7000. I am facing a problem. AF-S, AF-A, AF-C options are not showing in the camera monitor even after pushing the AF button and moving the dial. The different types of AF mode are not ...
2
votes
4answers
3k views

What is the formula for determining where infinity focus begins?

I'm having difficulty find any info on determining where infinity focus begins. I'm assuming there's a formula involving focal length and... Can anyone help?
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6answers
2k views

How to ensure sharp focus when shooting with an open aperture?

I've bought a Canon EF 50mm f/1.8 to use with my EOS 200D and while I love the wide aperture, it appears to be quite difficult to achieve sharp focus on people's faces when shooting at f/1.8. I've ...
1
vote
1answer
498 views

How do smartphone cameras know they are in focus?

I just wanna begin by saying that I have no real knowledge of cameras, so this might be a stupid question. But how do smartphone cameras know they are in focus? I would assume that if you told a ...
0
votes
1answer
159 views

Focus issue - possible cause?

I took a whole series of photographs of local listed buildings, so I could add them to wikimedia - until I saw the results. D5500 with Nikkor 24-120mm VR 3.5/5.6G 50mm ISO 100 1/320s f4.8 Full ...
1
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1answer
973 views

Why do mirrorless cameras have poorer autofocus that DSLRs in general

My question is similar to this but not quite. Why do mirrorless cameras have slower and less accurate auto-focus in general when compared to their DSLR competitors?
0
votes
3answers
132 views

Is it possible to upgrade Canon 1100D screen to one with better resolution?

While the question as per title can naturally be answered with "Just get a better camera", I still would like to know for the following reason: my 1100D still has some life in it and because I'm just ...
0
votes
2answers
130 views

Focus problems with all lens [duplicate]

Suddenly having a problem with out of focus or very very soft images. Doesn't matter if I use a Canon 50mm f/1.8 or a Sigma 70-200 or 24-70. I'm guessing user error or camera. Example image from ...
2
votes
1answer
3k views

How can I fix an out of focus photo? Is there an app for that? I don't have Photoshop [duplicate]

Someone else took this picture of me and didn't focus. :( How can I fix this? Is there an app for that? I don't have Photoshop.
0
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2answers
576 views

Nikon D3300 takes photos with no focus point

I know that photograppy is about the user and not the camera but when I have been taking pictures of birds in flight my camera can't hold a focus point. I have it set up for back button focusing in ...
3
votes
6answers
3k views

Why do we need a DOF preview button?

Why not just show the effective depth of field, by default? What's the point of having it display a picture that's different to how the image will actually turn out? My first thought was, it must be ...
1
vote
1answer
227 views

Focusing issue with kit lens

I have been using my camera (Nikon D5100) for around 5 years. Recently I am facing an issue when I use the kit lens. If I take a group photo (of a group of people) standing not very far from them, the ...
2
votes
1answer
261 views

Do fixed focus distance lenses exist for Micro Four Thirds?

I have a Panasonic GH5 camera. Is there a Micro Four Third lens that has fixed focus? I want a lens that would allow me to just shoot video of my son running around without using the AF/MF, I do not ...
2
votes
1answer
475 views

Why is my Nikon 18-300 lens not focusing at higher focal lengths?

I found a similar question about the 18-200. Someone suggested screwing the front element tighter. Is it possible to do the same with the 18-300? My problem happens at 200-300mm. I am not sure how to ...
0
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2answers
5k views

Why does auto focus on my new Fuji X100F keep moving while I have the shutter button held halfway?

I just bought a Fuji x100f and right out of the box I notice something with the autofocus (maybe it's normal and I just need to understand the camera). When you push the shutter button half way and ...
2
votes
2answers
133 views

Why is fine focus adjustment sometimes necessary on DSLRs? [duplicate]

Many DSLRs have a "fine focus adjustment" option, stored in the camera per lens. Why is it that some lenses need this? Why do some lenses not project a focused image onto the sensor when the camera ...
2
votes
1answer
174 views

Where to focus when taking a portrait of 2 people? [duplicate]

Could someone please tell me where to focus when taking a portrait picture of a couple who are standing next to each other. Thank You
2
votes
3answers
1k views

How can I refocus a downloaded Huawei P9 image?

I know of course, I can do it with the camera app on the phone if the "Aperture mode" has been activated. Is it possible to refocus such image once it's downloaded from the camera? How?
3
votes
1answer
625 views

What should I do when autofocus doesn't work on a Nikon D5100 and 18–55mm kit lens?

My brother bought a D5100 body only a few days ago and I've given him my 18–55 kit lens (I have a D3300). Today his focus stopped working (he might have fiddled with the settings a bit, I'm not sure). ...
3
votes
1answer
230 views

Why are specular highlights sharp when focusing on close object?

I am trying to understand how specular highlights work. As I understand specular highlights are created by reflecting light-sources in a mirror-like fashion. Because faraway reflected objects are out ...
1
vote
1answer
466 views

Why might focus fall off at the edges?

In the John Wayne movie Rooster Cogburn (1975), there is a dramatic focus fall off at least 10% of the vertical height at both the top and bottom of the lens. Why does this happen?
1
vote
5answers
2k views

How to get subject eyes/face in focus reliably with my Fujifilm X-T10?

I have been getting inconsistent results with focusing on the face using a Fujifilm X-T10 set to eye-detection focus. When the face takes quite a large area of the photo (like for a head and shoulder ...
0
votes
2answers
645 views

Canon 5D photos look terrible, possible Focus Screen issues?

I have an original Canon 5D. I cannot get good, sharp, clear photos no matter how much I try. They will look clear at one area, and distorted looking in another area. Not Bokeh or bad focus, but just ...