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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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Issue with focus when using the viewfinder

I've got a Sony A6500 with a Sigma lens (30mm 1.4 DC-DN). When I take a picture of a landscape (all green squares appear when focusing) it works nicely. However, if I take the same picture (with again ...
rockline's user avatar
1 vote
3 answers
54 views

What is the difference between working focus distance and infinity focus in Camera Lens (specially machine vision camera)

I am new to camera lenses and am trying to understand their details. I have learned concepts like aperture, focal length, FOV, IRIS, and different mounts (C, CS type, etc.). I have a question ...
Aravind D. Chakravarti's user avatar
4 votes
2 answers
142 views

The wrong focus in the cold

I took pictures with a "Start" film camera and, accordingly, 35mm. When photographing indoors, everything is fine, but only i take this camera outside in severe frost (below -15 ° C), the ...
Stiven's user avatar
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-1 votes
3 answers
91 views

How can I get a large depth of field with an SLR? [duplicate]

When smartphones are video recording stuff, pretty much everything is in focus, where as "big" cameras don't do this? If I wanted to record something with my camera I will have to constantly ...
Marcus's user avatar
  • 117
11 votes
2 answers
845 views

How can I make a focus ring More stiff?

I have a manual focusing samyang fisheye lens with one problem.... The focus ring is feather touch and even the aperture ring getings knocked easily. I want it to be less smooth so it's locked on to ...
deek's user avatar
  • 297
8 votes
5 answers
2k views

Why do people not use large f-numbers (small apertures) when shooting landscapes, when you want large depth of field?

When some people take photos of the landscape, why do they not use like a low f-stop like f/32, because wouldn't you want everyone in focus because it's a landscape? But quite a lot of people use f-...
Marcus's user avatar
  • 117
0 votes
5 answers
226 views

How can I get a large depth of field at night?

I am new to photography and have a question on aperture. What if I wanted to take a picture with majority of the picture in focus, but at night time, so I can't have the aperture too high, because it'...
Marcus's user avatar
  • 117
1 vote
1 answer
165 views

Why is only the extreme right of my photo blurred?

I was standing still on a platform ladder when shooting this photo, so not in motion. However, I have several other examples of posed photos like this where only the right side of the photo is blurred....
Timothy L. Miller's user avatar
0 votes
1 answer
75 views

Do I need to upgrade my camera for group portrait photography?

I have a D3500 with kit lenses which I use to shoot group portraits. I have read extensively about lighting, aperture, ISO, shutter speed, etc., and have applied my learning to my photos. I shoot all ...
setholopolus's user avatar
28 votes
10 answers
7k views

What is it about this albatross photograph that makes it look like it might either be faked or actually a photorealistic drawing (to me at least)?

When I first saw this photo of three albatross, it seemed wrong to me somehow - like the birds were hand-drawn and added to a photo of a background. It doesn't look like an actual photograph, but I ...
uhoh's user avatar
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1 vote
3 answers
98 views

Does unit focussing yield smaller depth of field than element focussing?

With unit focussing (also called bellows focussing, although a bellows isn’t intrinsically necessary) the entire photographic objective is moved relative to the film plane to set the focus. This also ...
Daphne Preston-Kendal's user avatar
0 votes
2 answers
93 views

Lateral blur in digital images

I would like to know if is there any term or concept to refer to the effect of lateral blur of the objects which reflected rays enter the optic surface tangencially. Is there any specific term for the ...
solysombra98's user avatar
1 vote
3 answers
334 views

Why are larger apertures used for astrophotography? [duplicate]

Learning about aperture, and depth of field. I have understood it as such ...
user's user avatar
  • 155
0 votes
2 answers
70 views

How is reflection sharp when not in DOF range? [duplicate]

This is baffling to me. When you use fast lens and you focus on a subject, you'd think that everything that's not in DOF range would be blurred but this is not the case if the object is a mirror or ...
netrox's user avatar
  • 201
0 votes
1 answer
191 views

Why can't my Canon 18-135mm IS focus to infinity when zoomed past 100mm?

My EF-S 18-135mm f/3.5-5.6 IS [non-STM/non-USM] cannot focus on my 7D to infinity when it is zoomed past 100mm in both auto and manual focus. It can only focus on objects at a shorter distance (say &...
caond's user avatar
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1 vote
4 answers
208 views

What is the definition of focal length for a camera lens?

I came across many articles where the focal length of a camera lens is defined as the distance between the optical centre of the lens and the sensor. One such article is here: https://photographylife....
LumosMaxima's user avatar
0 votes
2 answers
182 views

I want to measure far distance focus in a short space, but give myself a greater FOV, how would I do that?

Building off of this question, say I put a 1 m lens in front of a camera so I can see a virtual image at 500 m to focus to, when I place an object within the focal length (0.998 m), but I want a ...
user avatar
0 votes
2 answers
143 views

I want to focus at far distances but close, what lens could I use?

I want to be able to set the focus at far distances, like 500 m, but in a smaller setting, like 5 m. What lens could I use to achieve this? I have found this lens that achieves it for a FOV of 120 ...
user avatar
1 vote
1 answer
372 views

What can I do to improve my blurry indoor hockey photos?

I’m an amateur and just starting shooting my grandsons hockey. I’m using Nikon 18-300 f3.5 lens. My settings were 1/1000 f9 iso 5000 as it’s dark inside. Focus mode AF-C and dynamic area mode. The ...
Marilynh's user avatar
1 vote
2 answers
326 views

My Nikon D7100 autofocus fluctuates and will not focus on distant objects

I photograph with a Nikon D7100 with a Tamron 18-400 mm lens. My camera is set to autofocus but when I try to photograph a bird sitting on a branch that is BEHIND near branches, the camera vacillates (...
Hol's user avatar
  • 11
1 vote
4 answers
649 views

Pixel 6: Any camera app to stack subject and background into the same JPG, so that both appear sharp?

I often take pictures with food as the subject (foreground) and a monument in the background. Problem: Using a Pixel 6 smartphone, either subject or background is blurry. Reading How do I keep both ...
Nicolas Raoul's user avatar
0 votes
1 answer
128 views

How can a fixed-focus lens have a focus range of 0.5 meters to infinity?

I have a Mavic Air 1 drone and I was wondering how the camera of this drone can have a shooting range as large as 0.5 meters to infinity with a fixed focus? Mavic Air 1 camera specs: Parameter Value ...
Sebastyen Laroche's user avatar
9 votes
5 answers
5k views

How can I reproduce a myopic effect on a picture?

I want to accurately reproduce a myopic effect on a picture or a scene. I will explain... I'm a guy with very high myopia (20° to round). I want to show people how I see without my contact lenses. I ...
efirvida's user avatar
  • 191
3 votes
1 answer
580 views

TTArtisan 25mm f2 lens focus ring adjustment

The lens: https://www.ttartisan.com/?list_10/152.html I bought this lens now twice for my Fuji X-E1, and both lenses had identical infinity focus issue. Infinity mark is not focussed, I have to move ...
MOTIVECODEX's user avatar
4 votes
2 answers
1k views

How can I find a lens locking screw if I have lost the original one?

I have an industrial camera with a C-mount lens, like this one: (Source of image, last accessed 2022.11.02.) You can see a tiny screw on the top of the picture. It is used to lock the focus ring or ...
LimeAndConconut's user avatar
2 votes
7 answers
646 views

Why is the commonly utilized aperture for moon photography much higher than that provided by DoF formula?

in this Moon Photography Guide, a F-Number equal to f/11.0 is suggested. In many answers in this forum, similar values are suggested (ranging from f/8.0 to f/11.0). Even if someone suggests f/5.6, it ...
Kinka-Byo's user avatar
  • 514
1 vote
1 answer
206 views

Calibrate Argus C3 focus

As a personal project I bought a broken Argus C3 on eBay, and managed to completely clean and fix it, however it involved taking the lens apart since there was dead insects and dirt inbetween the ...
Matty's user avatar
  • 55
0 votes
3 answers
201 views

Do photographic lens show virtual image if the subject distance is less than focal length?

A convex thin lens produces a real inverted image if the subject distance from the lens is higher than the focal lens. If it is lower, the image will be virtual. Of course a virtual image appears on ...
Kinka-Byo's user avatar
  • 514
3 votes
3 answers
715 views

Why do mirrorless cameras still backfocus?

If mirrorless cameras focus through the lens and directly focus using the image on the sensor, why do some lenses still backfocus and need calibration? What is the mechanism that allows this issue?
Ana's user avatar
  • 43
0 votes
1 answer
137 views

To infinity... and beyond? [duplicate]

In the old days when I wanted to take pictures of distant objects, like landscapes, with my 35mm OM-2 I would just move the focus all the end: infinity. Now, however, my lenses focus past infinity. ...
Clickety Ricket's user avatar
0 votes
1 answer
80 views

Camera not working while shooting long distance

I have a nikon 3200 and lately I have observed that it does not allow me to take any photos if the lens is not zoomed. It doesnt even focus or take any picture even when I click the button. I checked ...
Nik's user avatar
  • 1
1 vote
1 answer
294 views

Focus ring on Canon 18-200mm stuck

I am very new to photography and my 18-200mm lens by canon has gone broken. The focus ring seems to be stuck. It nearly does not move at all when there is no zoom and it moves roughly when zoomed out. ...
Rasse's user avatar
  • 11
0 votes
2 answers
217 views

I keep slightly missing focus in Live View. Is there a way to recalibrate it so it matches viewfinder focus?

[I have a Nikon D5600, but I'm sure any answers and talking points will be relevant to other brands too.] When using Live View to focus, I've noticed that I often slightly miss focus. I've heard the ...
user382459's user avatar
2 votes
4 answers
3k views

Image is Blurry, but Viewfinder is sharp

I recently bought a Canon 550D. The problems is when I take a picture through the ViewFinder, the image gets blurry and out of focus. But when I use Live Mode, the image is sharp and in focus. What ...
Niks's user avatar
  • 21
2 votes
2 answers
811 views

Terminology for camera focus values

I am a software developer writing a software interface for a Bosch mic 9000i camera. I have an interface to change the focus of the camera and I'm writing documentation for an end user. The numeric ...
Nate Anderson's user avatar
0 votes
2 answers
869 views

Do my photos look blurrier on a newer, higher-resolution camera body because my lens has a problem?

I have a Canon EF 100-400 1:4.5-5.6 L IS USM (the old version, not the II) zoom lens, which I often use for bird photography. I used to have a Canon 10D body, which I used in combination with this ...
CesarGon's user avatar
  • 103
2 votes
3 answers
252 views

Get correct focus on low light with modelling light

I'm looking for a good way to get "perfect" focus on lower light environment. I'm doing product photography (top down) of textiles with two flashes. The flashes have a model light (is that ...
jona's user avatar
  • 123
3 votes
2 answers
616 views

Focussing issue with Canon 90D and Tamron 24-70

A few weeks ago, I took wedding photos for a friend of a friend. A problem I had been having lately suddenly became very apparent: a lot of photos I take are not in focus. The focus indicators of my ...
Wouter C's user avatar
  • 131
4 votes
2 answers
108 views

Panning - narrower focus than expected

When panning, I find that I can keep the entirety of subjects in focus when they're moving perpendicular to me -- straight L-R or R-L, as in this shot: However, I notice that when I'm panning in ...
D. Lambert's user avatar
  • 10.5k
2 votes
1 answer
224 views

AE-Lock and Re-compose

I'm confused on how AE-lock works. I was advised and also tried this. Walk into a room point at what I want to capture, lock the exposure with AE-lock. Re-compose and take the shot. In theory the shot ...
Big Joe's user avatar
  • 293
1 vote
0 answers
331 views

online image focus detection or app

I am wondering if anyone knows of an online image focus detector programme that will detect that the image is in focus without having to painstakingly go through and printing all images. I have ...
Tracey Simon's user avatar
3 votes
2 answers
4k views

Can I post-process this out of focus image?

There was a small snake hiding in the grass. I pointed my camera, but I zoomed too much. When I pressed the button to adjust the focus, the autofocus complained because it was out of range. I tried ...
FluidCode's user avatar
  • 171
2 votes
2 answers
225 views

How to configure the FujiFilm X-T30 to take a selfie while holding a baby?

I'm trying to take a selfie while holding a baby, but the FujiFilm X-T30 keeps only me in focus, leaving the baby is out of focus. Is it possible with one of the auto settings to keep both of us in ...
TMOTTM's user avatar
  • 123
23 votes
6 answers
6k views

What are the best (ethical) ways to keep insect still for outdoor macro photography?

What are the best techniques to improve the details of my insects macro shots ? I don't want to kill them, and ideally, would like to use some focus stacking. I shoot handheld (with a Laowa 2X), with ...
GhislainCote's user avatar
1 vote
2 answers
794 views

D7200 no longer autofocusing

AF on the body of the camera M/A on the lens Back dial is not locked I've tried clicking and holding the AE-L/AF-L button Tried two different lenses Battery is full In the viewfinder, I see two arrows ...
krapzz's user avatar
  • 11
1 vote
0 answers
392 views

Auto focus won’t work in viewfinder on Aperture priority mode

My camera (Canon Rebel t7i) won’t auto focus in manual or aperture priority mode in viewfinder. (It works perfectly in liveview) Maybe it’s important to say that I’ve never shot in manual mode so I ...
Emnsmnc's user avatar
  • 11
1 vote
4 answers
1k views

Why I am unable to focus at all while using ND filters

Lately, I am unable to focus with ND8 AND ND10 filters put over the kit lenses of my Canon1300D camera. Whenever I try to focus, it allows me to only reach to a point where the subjects are only ...
pixhibit.samco's user avatar
1 vote
1 answer
109 views

How to calculate depth of field at different resolutions

I have a DSLR (EOS 60D) and I use hyperfocal pro when setting up astro-photography. At lower resolutions though, such as in video mode, how can I calculate the depth of field? The field of view barely ...
MParks's user avatar
  • 21
0 votes
2 answers
293 views

How can I measure the exact range of focus of a given fixed focus webcam?

By moving objects around the camera I can see that they get very blurry at 10cm and less sharp at 3-4m away from the camera but how can I measure the exact range of focus? If I check the sharpness of ...
OMGsh's user avatar
  • 133
2 votes
0 answers
415 views

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 ...
Esther's user avatar
  • 21

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