Questions tagged [focus]
Focus is the mechanism of converging light from a point light source onto an imaging plane by a lens.
568
questions
4
votes
2answers
85 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 ...
2
votes
1answer
84 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 ...
1
vote
0answers
58 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 ...
3
votes
2answers
3k 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 to much. When I pressed the button to adjust the focus the autofocus complained because it was out of range. I tried ...
2
votes
2answers
71 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 ...
21
votes
5answers
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 ...
1
vote
1answer
97 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 ...
1
vote
0answers
133 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 ...
1
vote
4answers
377 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 ...
1
vote
1answer
83 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 ...
0
votes
2answers
57 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 ...
1
vote
0answers
73 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 ...
15
votes
4answers
3k views
How do I tilt a lens to get an entire street in focus?
What is an efficient strategy to get a particular plane in focus by adjusting:
the tilt (or in the example below, the swing)
the focus distance (or rather the focus angle, for a tilted lens)?
I'll ...
0
votes
1answer
130 views
K10D poor focus - manual or auto - with full-frame zoom lens
I'm getting very poor focus particularly at the long end of an 80-320mm tele lens that I am using with my Pentax K10D.
The lens was originally bought for my 35mm Pentax SLR (maybe an MZ5 or something, ...
1
vote
1answer
153 views
Dismissing red frame in close up [Canon EOS M50]
Is there a way to take a shot even though the red frame indicating out of focus appears?
When I am trying to take a picture few inches away from something the red frame appears. Someone asked similar ...
5
votes
4answers
1k views
What causes images to have flat depth?
I am learning about photography and I remember reading about an effect that causes images to look like there is no depth but now I cannot find what it is called or what causes it.
I remember an ...
1
vote
2answers
114 views
Would a screw in 2x converter double the minimum focusing distance?
I want to shoot some very zoomed in shots, my current lens has a 28cm minimum focusing distance. I want to shoot from 35-40cm away but more zoomed in. Sort of macro, but from a distance.
If I bought a ...
1
vote
2answers
151 views
Focus problem with Opteka 500mm mirror lens
Ok, I'll lead with the fact that I know this is a cheap lens and they're notoriously difficult/impossible to focus well.
But ... something is strange here.
I took this lens out to try and get some ...
0
votes
2answers
91 views
How to properly focus using a Macro reverse ring?
Fourth question from me about this topic.
I'm trying to digitize a large number of family slide films with a modified slide projector by taking photos of the slides (I replaced the original yellow ...
1
vote
1answer
246 views
Picture gets blurry when zooming in
My Nikon 3400's kit lens(18-55mm) works fine when I take pictures at 18mm. But when I extend lens beyond that, the picture gets blurry(no clarity). Though I can focus on extremely close distances ...
1
vote
1answer
508 views
Err 01 and no manual focus (Canon lens)
my Canon EF-S 18-55mm f/3.5-5.6 IS STM just stopped communicating with my DSLR (Canon EOS 77D). Furthermore, I can't even use manual focus anymore.
Right before this happened, I tested some extension ...
4
votes
2answers
344 views
Modifying a film camera to display images
My dad passed recently and I would like a way to memorialise him and his photos.
He was an avid photographer and never left home without his camera. The one I remember from growing up was an Asahi ...
1
vote
1answer
154 views
How can I produce high quality images of field ranges for training sets?
I am an Agronomic researcher assisting on a ML problem for identifying soy diseases. I would like to capture an image of a single range of soy (roughly 1' wide by 5' long) that is at least mostly in-...
1
vote
1answer
83 views
Mounting large format lens on PB-4 Bellows
I have a PB-4 bellows. I want to mount a large format lens on the bellows so it can focus to infinity and I will have a very versatile tilt/shift bellows. So I am just wondering if there are any ...
8
votes
8answers
4k views
How can I get sharp bird photos when the bird is further away?
I have Canon 1200D. I use the 55-250mm kit lens for bird photography.
Laughing Dove
ISO 400, 1/100, 250mm, cropped, shot late in day in overcast conditions, brightness increased in post processing
...
1
vote
4answers
381 views
Focussing on a star with wide angle 14mm lens
Has anyone discovered a better way than trial and error to focus on a star - (for Milky Way Astrophotography)? I am using a Canon 5D Mk2 with a 14-40mm lens at 14mm. My Settings are ISO 12800 and ...
3
votes
3answers
278 views
Why can't I reproduce a back-focus problem at home?
I'm a bit out of ideas. Lastly, my Nikon D7000 started to have severe back-focus problems. When I shoot photos of birds and other animals, or portraits of persons, in average, four out of five photos, ...
2
votes
1answer
153 views
Shutter activates when manual focus is achieved. How?
I have a canon 5D mk ii which I've been using for donkeys year. I was messing about with a new lens in the office today and somehow stumbled on a feature I've never noticed before.
Using manual focus, ...
2
votes
2answers
405 views
Canon 250D not focusing on Self Timer [duplicate]
I want to take some smart photos of myself with my Canon 250D. I have it set to 18mm so I can stand a bit away from the tripod. I then put the camera on a 10 second self timer. Eye AF is on.
When I ...
2
votes
5answers
281 views
Can digital zoom affect focus
I was always under the impression that digital zoom has little use since the same thing can be achieved on a computer afterwards by cropping.
I recently purchased a point & shoot digital camera ...
1
vote
3answers
124 views
Is the sharpness of imaging different within the depth of field?
Is the sharpness of imaging different within the depth of field? Where is the sharpest? What I am asking is the distance from the lens to the object, not the image distance in the lens. How to ...
3
votes
3answers
244 views
Distant objects not in focus
This is almost certainly my fault, not the camera. I mostly shoot landscapes with myself in the foreground via a small tripod:
My former camera was a Sony A5000 and for these kinds of shots (see ...
1
vote
2answers
72 views
Convex lens, object distance, distance, focal length, in what state is the hyperfocal state? [closed]
Suppose we have a convex lens for a middle school physics experiment, a screen, and an object being imaged, under what state will we find the hyperfocal state?
The screen is the imaged screen. It can ...
1
vote
2answers
176 views
Using a modern lens (with electronics) manually?
Long story short:
What I have:
Panasonic GH4
Endless 3D printing options for making my own adapters
Very, very nice japanese retro prime lens from almost 50 years ago (yeah, it really looks ...
6
votes
3answers
255 views
What is this style of photography called?
I am trying to learn a specific type of photography and am having a difficult time finding out the name for it. What I am most interested in, is a specific niche of high focus, minimalist, black ...
3
votes
5answers
539 views
Focussing with Extension Tubes
I bought a set of extension Tubes to use with my Nikon D5300 and 35mm f/1.8 lens. However, it seems that the only option to focus is to change the distance to the subject. This is very inaccurate and ...
0
votes
2answers
275 views
Why is my Nikon D5500 unable to lock focus while using Live View but works fine when using the ViewFinder?
It just keeps trying to find focus. If I press the half-click focus button I hear the motor moving and the numbers on my lens go from smallest to infinity and stop. If I press the half-click focus ...
-2
votes
2answers
187 views
When the object is 50 meters away, how do you know that the camera is focused at a distance of 50 meters?
When the object is 50 meters away, how do you know that the camera is focused at a distance of 50 meters? Is it that we can only focus at about 50 meters?
-2
votes
3answers
332 views
What is the acceptable CoC (Circle of Confusion) of the human eye to directly observe the object? [closed]
What is the acceptable CoC (Circle of Confusion) of the human eye to directly observe the object? The human eye has many cells and high pixels. Should the permissible circle of confusion be small?
5
votes
2answers
496 views
Is there an effect opposite of tilt-shifting?
Is there any effect that would make objects seem much larger than they actually are?
I tried to google for it and the only thing I could find was a discussion on flickr where focus stacking is ...
-3
votes
1answer
101 views
For the formula 1 / u + 1 / v = 1 / f, what is infinite depth of field or hyperfocal distance?
For the formula 1 / u + 1 / v = 1 / f, what is infinite depth of field or hyperfocal distance? In other words, when u, v, and f, we have infinite depth of field or hyperfocal distance?
1
vote
2answers
196 views
What does focusing mean? What does it have to do with the formula 1 / u + 1 / v = 1 / f?
What does focusing mean? What does it have to do with the formula
1 / u + 1 / v = 1 / f
u is the object distance,
v is the image distance,
f is the focal length.
Does focusing mean that both ...
0
votes
1answer
50 views
Measuring Change in Focal Length
I have a Nikkor 28mm f/2.8 prime lens. I understand that this focal length is only valid when the focus is held at infinity. Is there a way to easily measure how the focal length changes when I adjust ...
0
votes
2answers
88 views
Selective focus optical illusion [duplicate]
I have come across some shots from other people and they create something like an illusion to me and trick me of the scale of the actual scenery.
For example, this shot by @chuttersnap on Unsplash ...
2
votes
3answers
175 views
Is the hyperfocal distance calculation outdated?
The hyperfocal distance H is calculated by H = (f^2)/(N*c)+f where f is the focal length, N the f-stop and c the circle of confusion limit. Lets assume we use a fullframe sensor. All those calculators ...
1
vote
1answer
137 views
What could cause the focus to be off in some images and not others?
I took a number of photos like the one here. Each was at the same settings but each time I asked the camera to focus (with a single focus point) and the focus point right on the girls face. The ...
0
votes
2answers
182 views
Calibrating a lens...is auto focus less reliable when zoomed?
So, I'm calibrating my lenses to a new camera body, a 5D Mark IV. When calibrating my 70-200 ƒ2.8 (version 1), I found that the focus was accurate at 70mm. However, when I calibrated it at the 200mm ...
0
votes
1answer
281 views
Is a Siemens star, printed with laser printer, suficiant for sharpness testing?
I have a Samsung SCX-4600 and I decided to make a Siemens star out of it using an A4 paper with vector to very high resolution PNG illustrations.
Is it an decent choice? How will it compare to a ...
2
votes
1answer
242 views
Are internal focusing primes actually uncompensated varifocal lenses?
If I shorten the focal length of a lens without taking any other measures, that will reduce the required flange distance for infinity focus - meaning that if the actual flange distance is not changed, ...
0
votes
2answers
578 views
Why can't I turn the focus ring on my Vivitar 100-300mm far enough to get infinity focus?
I recently bought VIVITAR 100-300mm F5.6-6.7 macro zoom. I use it with Nikon D70S. Here is my problem. When distance between my D70S with VIVITAR and object of photography is 15meters and more, I can ...
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