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Photography

Questions tagged [focus]

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

469 questions
info newest frequent votes active unanswered
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91 views

Does shift based perpsective correction have any effect on focus?

Consider a photographer with an SLR camera and a PC lens attached in its default, unshifted position, standing on the ground at the base of a columned building whose height is X times that of the ...
0
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2answers
91 views

What lense and flash should I get to take pictures of kids?

I'm new to having a camera and I'm not sure how everything works with my DSLR. I have a T6, and I would like to take pictures with flash without the kids squinting and that it is fast when I shoot. I ...
0
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1answer
45 views

Viewfinder shaking in my sigma 18-200 lens with Canon eos1100d

So, I dropped my camera yesterday wasn't a big drop and it was in its bag but today when I tried to use it the viewfinder has got an almost constant shake on it and all the photos are out of focus. ...
1
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3answers
142 views

A projection of a real-image is one fixed perspective, but looking through the lens with my eye, I see many perspectives. Why?

Assume that I have a camera obscura (with a large lens - something like a magnifying glass) setup projecting an image of some still life. I look at my projection on my projection plane and I see one ...
2
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2answers
113 views

Why can my eye focus on the real image of a convex lens at many distances from the lens, but a projection only works at a specific distance?

Say I have a single convex lens. I set it up like a camera obscura, shine a light on my object and project the image onto a projection plane. Given the focal length of my lens, the projection plane, ...
2
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1answer
111 views

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 ...
-1
votes
1answer
119 views

Sentimental photo taken by an iPhone out of focus

First let me say I am not a photographer, however I have a photo that was taken of my mom, myself and niece that is very dear to me. The photo was not properly focused I don't think. Could a ...
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0answers
42 views

My nikon d5300 camera won't take a photo nor will it focus?

I got my camera for Christmas (couple of days ago) and it was running fine! The focus was amazing etc. Then all of a sudden today, it won't focus. When i half shut the shutter, a noise is created (...
5
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2answers
523 views

One camera unable to focus in low light, different camera, same brand model, has no problem

With a Canon T3i mounted in a camera/flash tower, the camera cannot focus in low ambient light with dark complected subjects. All the settings are preset as this is being used in a drivers license ...
1
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2answers
63 views

Is it necessary to use focus point selection if I use back button focusing?

I'm a beginner in photography who just started using back button focusing.
2
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2answers
39 views

Focussing 100mm Auto Bellows Minolta lens on Bellows I with slide duplicator

I have a Minolta Auto Bellows 100mm lens (no focussing functionality, just aperture), that I am trying to use to duplicate slides with a A7R III and Minolta bellows I, focussing rail and slide ...
0
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1answer
92 views

How to enable back button focus on a Canon EOS 1300D?

I have recently switched cameras to a Canon EOS 1300D and I am unable to find how to enable back button focus. Does anyone know how to enable it?
0
votes
1answer
82 views

Focus Mode issue with the Nikon 7200

It is my understanding that to change the Focus mode you press and hold the AF - Mode button next to the lens and then rotate the knurled dial on the back of the camera. Then you select your desired ...
4
votes
2answers
250 views

Is there really a trend of portraits where the subject is not in focus?

My wife told me is a trend to aim out of focus on portrait shot. Maybe like focus on the background and let the main subject look blurred. Is there such trend? What kind of photography is this? Anyway,...
3
votes
2answers
98 views

Focus on near eye in backlit situation

As far as I am aware, for a portrait of a single person, focus should be on the eye closer to the camera, as a rule. Does the same apply in more or less backlit situations, i.e., when the near eye is ...
4
votes
5answers
424 views

Why use ultra-wide with short focus?

I have a Samyang F/2.0 12 mm for the Sony E Mount, so the 35-mm equivalent focal length is 18 mm (crop sensor 1.5×). I use it mainly for landscapes and architecture in order to fit more in my frame ...
1
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4answers
150 views

Are all prime lenses designed so that the same DoF scale applies at any focusing distance? If so, why?

This question is about the mapping between the angular position of the focusing ring and the focusing distance. This mapping could be anything but the design of prime lenses seems to be such that a ...
6
votes
4answers
187 views

Why does this thin plate disappear when changing focus

I am photographing a very thin plate (0.01" thick) that is partially submerged in a tank of water. My goal is to find the angle that the water surface makes with plate. When I focus on the front edge ...
3
votes
1answer
103 views

Focusing techniques with old folding camera (Agfa Isolette/Jsolette V)

I inherited one of these from my grandmother recently. Bought new in Romania in the 1930s or 1940s, can't remember. Anyway, I've been shooting all kinds of films with it, and have gotten ...
4
votes
3answers
131 views

How can I focus on someone who is in motion and still get them in focus with a wide aperture?

I'm trying to figure out the best technique to use for photographing people in motion. I would love to do weddings one day - but for now I’m concentrating on just getting my focus down (with a very ...
-1
votes
1answer
71 views

DSLR cannot focus after short drop

Have an old Canon 300D which suffered a drop onto hard floor from less than half a metre. It was in a bag, with a lens attached, and there is no visible damage. However, it seems to have lost the ...
1
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4answers
223 views

Wondering about the metering mode and focus area? [closed]

I just learn about the metering mode and focus area on youtube. But i am wondering about are they on at the same time? I got a sony a6300 camera.
3
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2answers
105 views

Pentax K-x with kit lenses problem producing sharp photos [duplicate]

Hey guys I have recently dug out old Pentax K-X with kit lenses, but I noticed I struggle with sharpness of the photos. No matter what settings I try I get my photos blurry when I crop it to make ...
1
vote
2answers
87 views

How to accurately determine the size of a nearby object (~15cm) using the autofocus focus distance?

The problem I'm trying to determine the size of an object using the focus distance determined by the autofocus of a smartphone camera (Galaxy Note 8). But I don't seem to be able to get an accurate ...
1
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1answer
140 views

Is it normal for focus to “drift” in timelapse mode?

I use a Canon 77D with a 24mm 2.8 STM lens. If I set the camera to back-button focusing, focus, then take a short series of shots, everything looks fine. But if I leave the camera in timelapse mode (...
1
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0answers
26 views

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 ...
0
votes
2answers
458 views

My DSLR's autofocus doesn't work after I dropped it — how can I narrow down the problem?

If I try to focus by the shutter button the image doesn't change, even in live view (and I'm not be able to shot a picture). But if I hold the "AE-L/AF-L" button and click the shutter button I'm able ...
1
vote
1answer
424 views

Panasonic Lumix TZ100 - how to stop autofocusing and just get everything in equal focus?

I’m an amateur photographer and would like to ask for some help! I’ve recently bought a new camera, a Panasonic Lumix TZ100. Before that for 5 years I was using a Canon Ixus 255 HS. So far I haven’t ...
0
votes
2answers
139 views

Manual focus in A mode can harm my lens? [duplicate]

I use 18-140 Nikkor . This lens have two A & M focus mode and this lens is AF-S that mean when auto focus is enable the focus ring dose't move. If i do manual focus when the lens is at A mode , ...
1
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1answer
196 views

Manual focus lens on fixed focus camera?

Hello i have bought this camera: It is a lens type camera, but it has a FIXED focus. I read on the internet that if I buy and put a manual focus lens it will work? Is that true ? If it is true ...
3
votes
4answers
286 views

Is recomposing ideal rather than changing focus point?

As a beginner in photography I’ve stumbled across several videos stating that the center point is the sharpest and most accurate point as apposed to the others. I’ve seen many photographers take ...
8
votes
3answers
1k views

How to avoid the grainy background in sunset picture?

I was taking this picture of the sunset. I used auto focus, but the trees are not really that focused. Also, the red background is grainy. Any tips if I get this opportunity again? I was using a ...
3
votes
2answers
192 views

Focal length measurement and definition in DSLR cameras [duplicate]

So i am a bit confused when it comes to focal length in DSLR cameras. According to multiple sources online i found and as per NIKON "It is a calculation of an optical distance from the point where ...
3
votes
2answers
141 views

How to take a macro photo, but with the subject completely in focus [duplicate]

I love macro photography, it gives an insight in the small world around is. Unfortunately, I'm really not good at it. When I came across an artificial beehive, I took a chance to get into the bees and ...
5
votes
1answer
79 views

Are focus and resolving power optically equivalent?

Limited "resolving power" or "sharpness" is a problem one can see with many lower-quality lenses, especially with higher-resolution camera bodies. Playing with my cheap 500mm mirror lens, I often get ...
4
votes
1answer
561 views

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....
1
vote
2answers
1k views

70-300 AF-S Lens Won't Autofocus on one of my D7100's

I recently purchased a used Nikkor 70-300 AF-S VR lens used from B&H that is in "Excellent" condition. I have 2 Nikon D7100 bodies that I shoot with and both autofocus just fine with all of my ...
1
vote
2answers
1k views

Tamron lens focusing problems?

I own a Tamron 18-270mm F/3,5-6,3 Di II VC PZD lens - a fabulous lens, but since I got it (around Christmas time), the autofocus has been playing up; see below image. EXIF is as follows: 270mm, ...
0
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4answers
369 views

After I dropped my lens, focus locks but images are blurry — what could be wrong?

I have a Tamron 24-70 2.8 on a D610. I usually go for small apertures (F11 to 16) since I work with flashes on studio setups, my lens gives sharp images on those appertures but anything below F5.6 ...
3
votes
3answers
421 views

Why can't my compact digital camera focus when applying 8x zoom?

I have a compact digital camera which is Canon IXUS 165. The specification is in this link. I bought it in June 2016. It has 8x Optical Zoom. Just now I was zooming 8x on something, and when I tried ...
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
votes
2answers
129 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 ...
10
votes
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 ...
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votes
1answer
348 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
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1answer
56 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
vote
3answers
188 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, ...
1
vote
2answers
133 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
256 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
votes
1answer
117 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
votes
3answers
1k 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 ...

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