Alley in Pisa, Italy

by Lars Kotthoff

submit your photo


Hall of Fame
View past winners from this year

Please participate in Meta
and help us grow.

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

learn more… | top users | synonyms

92
votes
7answers
7k views

What is bokeh, exactly?

I understand that "bokeh" refers to out-of-focus areas of an image — but there is obviously more to it than that. What does the term mean exactly? How well is bokeh really understood? Is it purely ...
56
votes
15answers
8k views

How does one focus for landscape photos in very dark conditions?

Tonight I tried my best to take some night landscapes in the darkest of dark conditions. Hoping for an epic composition of the Milky Way and a landmark. Of course, none of my glass could auto focus ...
32
votes
7answers
1k views

What is “Hyperfocal Distance”?

I'd like a clear & easy-to-understand (especially for non-physics-types) explanation of what Hyperfocal Distance is, how it affects photographs, and what determines its value.
23
votes
4answers
2k views

What tips and advice do you have for photographing the Aurora Borealis?

A friend has been kind enough to lend me a DSLR for a few months. It's my first foray into DSLR photography, or indeed any kind of photography beyond simply aiming my Canon IXUS at something and ...
27
votes
8answers
3k views

What is the advantage to back-button autofocus?

I've heard some advanced photographers talk about using back-button autofocus. As I understand it, this involves changing one of the camera's custom setting to engage the AF when a button on the rear ...
21
votes
7answers
7k views

How to nail focus for DSLR astrophotography?

I've been doing a bit of astrophotography and the problem that I almost always have is nailing focus. I'll manually focus on a bright star or the moon (which hopefully isn't an option!) by magnifying ...
23
votes
5answers
1k views

What are the best practices for DOF stacking?

What are the best practices for DOF stacking? How do you get the frames with focus just right amount apart? How do you stack them in post processing?
13
votes
4answers
4k views

How does changing focal length affect depth of field?

I'm curious about how my "area of acceptable focus" changes when the focal length of the lens I'm using changes as I zoom (or switch lenses). In particular, I'd like to know how the front & back ...
24
votes
3answers
2k views

Does changing the focal length change focus?

When using manual focus or back focus on D60, I sometimes zoom in the lens, set the focus, and then zoom out. Does changing the focal length (zooming out), also change the focus? In case the answer ...
25
votes
13answers
7k views

How does one get manual focus right with a fast-aperture lens?

I have got an old lens (f1.4) that I have to use only with manual focus on a DSLR. Well, it is difficult for me to get the subject on focus. Although on focus according to the viewfinder, the actual ...
15
votes
4answers
2k views

Why can't my SLR autofocus on certain parts of a scene?

I had my Nikon D7000 on single-point auto focus and it just would not focus on the spots I wanted. I have marked the spots that could not be focused on with red circles, and the parts that could be ...
23
votes
9answers
3k views

Why would I want to select an autofocus point?

I'm trying to understand why I would ever want to select an auto focus point other then the center point. I have a Canon XTI Rebel DSLR which has 9 auto-focus points, but I'm also looking into getting ...
8
votes
4answers
2k views

How can I get maximum DoF with no distance markers?

I am aware of what hyperfocal distance is and the general principles behind it. However, most of the tutorials I have seen and read regarding it make use of lenses with focus distance indicators. ...
6
votes
3answers
4k views

What is the technical difference between focus and zooming?

This may look like a silly question but I don't know what the difference between zooming and focusing is. Zooming in will usually let me have fewer subjects in the scene while zooming out will allow ...
5
votes
2answers
2k views

What is the effect of the number of cross-type focus points on sharp focus?

Canon claims that EOS 6D has special capability to focus in low light, but it has only one cross-type sensor and overall only 11 focus points. Does only one cross-type focus point in the Canon EOS 6D ...
23
votes
18answers
2k views

What are some techniques for hand-held image stabilization?

My zoom lens (75-300mm) is fairly slow: 5.6 at its farthest point. (I think it's 3.5-5.6, and it's not image stabilizing. I'm on a budget, sadly!) Unfortunately, my primary use for it is hand-held ...
20
votes
8answers
3k views

How do I focus in low light for long exposures?

I've been trying to take some long exposure shots at night with my Canon 450D. The problem I'm having is that I can't seem to get a shot in focus. The low light conditions prevent AF from working at ...
7
votes
2answers
2k views

How can a prime lens focus on more than one plane?

By definition, a prime lens is a fixed lens system with a fixed focal length. Then, simple physics tells us that it should be able to focus only on one plane (at a fixed distance) in front of it. But ...
6
votes
4answers
1k views

Are there macro focusing techniques for handheld shots?

I know that when doing much macro work that the autofocus system is nearly useless. When hand holding and trying to manually focus, I find myself continually going a little too far or just not far ...
6
votes
2answers
778 views

How can I get more of this macro photo in focus?

I want to make a full focus on the body, for example: I need to have a clear focus on the each balls in the photo. I used just single point focus. In this picture I used: shutter speed: 8 ...
6
votes
2answers
3k views

How can I take a photo with everything in focus with my DSLR?

I am quite new to DSLRs and one of the first things I noticed was the incredible focus points and depth that you can achieve. That is great in a lot of scenarios, but not in all. When filming a ...
28
votes
4answers
39k views

What is back-focusing?

What is back-focusing? Is it something I need to be worried about, or can I just live with it? How can I tell if my camera/lens is sufferring from it?
21
votes
3answers
6k views

How can a 18-55mm lens focus on objects beyond 55mm?

I guess this is a total noob question, but doesn't 18-55mm mean that it can focus only up to 55mm?
3
votes
2answers
3k views

Do the issues with sharpness I am seeing require AF fine-tuning?

I own a nikon D7000 with 18-105 lens. I am not happy with sharpness I get with autofocus in portraits. I read about front/back focusing, but I am not sure whether my gear has this issue. Is this issue ...
12
votes
4answers
815 views

How close can a lens focus?

From my understanding, if you want to do some macro photography it is better to have a lens that can focus when it is really close to the subject. Sometimes people buy extension tubes to help them ...
8
votes
3answers
1k views

How can I take photographs with a large depth of field?

I was looking at some pictures by TSO Photography, and I was struck by how everything in the image seems to be sharp and in focus. I do realize that to achieve huge depth of field, you set the ...
12
votes
4answers
1k views

How do you use the different autofocus points on your DSLR?

My Nikon D300 has quite a few autofocus points. There's a button I can operate with my thumb to change the autofocus point but I find that quite difficult to use. So I almost exclusively use the ...
9
votes
1answer
3k views

What is the difference between depth of field and depth of focus?

Reading this answer I realized that I didn't know the difference between the two depths (of field and focus). Browsing related questions didn't reduce the blur (!) between the two... Wikipedia ...
3
votes
4answers
20k views

How can I fix an out-of-focus blurred photo in Photoshop?

How can I fix this picture? Somebody else took this picture and well he wasn't able to do it very well, and it's blurred. I have photoshop
32
votes
7answers
6k views

How can I get sharp manual focus despite poor eyesight?

I suffer from astigmatism. It's only mild, though I feel it's affecting what I'm seeing when looking through the viewfinder. Frequently, after shooting a photo with my Canon EOS 7D, I'll load it into ...
15
votes
3answers
3k views

Can software auto-detect image focus?

I was wondering if there was any photo management software out there that could auto detect and "rate" images on how in focus they are. This comes up for me quite commonly when i am looking through a ...
11
votes
5answers
8k views

What is “infinity focus”?

I have been reading a bit about astrophotography and the term infinity focus keeps coming up. What is infinity focus and how do you set the camera to infinity focus?
7
votes
4answers
1k views

Why are my photos taken at f/11 less sharp than those taken at a wider aperture?

I am new to photography. I have Fujifilm FinePix HS10 camera. Lately I was trying my hands on landscape photography. I learnt from different tutorials that setting high aperture value gets most of ...
13
votes
1answer
11k views

How does focus work on mobile phone cameras?

How does focusing work on mobile phone cameras? Aren't their optics simple enough to not have any moving parts whatsoever? If so, how come most smartphones have an auto-focus, and with various ...
8
votes
2answers
655 views

How can I “focus peak” a photograph?

Does an application exist where I can input an image and then the application indicates what parts of the image are in focus? I imagine it as a sort of post-process focus peaking.
8
votes
4answers
3k views

Is it difficult to focus on 1.4F prime lens, and if it is how to counter that?

Does difficulty in focusing have anything to do with 1.4F (Nikon G)? Will it be still difficult if I use manual focus? Is auto focus too slow? Is there a way to counter it? This example photo (from ...
7
votes
1answer
5k views

How do I determine focus points in Adobe Lightroom?

Not sure if this is possible or not in Adobe Lightroom. I would like to see the focus points chosen by my Canon DSLR. I am guessing this is stored somewhere in the EXIF, but I'm not certain. I find ...
19
votes
2answers
1k views

Why am I allowed to turn my focusing ring beyond infinity?

Is there a good reason why I can turn the focusing ring on my lenses beyond infinity mark on focusing scale? Following recent questions here and here, it sounds like a real usability issue. ...
6
votes
1answer
348 views

When focusing at max zoom, focus is lost after zooming out. Is that normal?

On my Canon kit lens, I could completely zoom in, focus on the object and then zoom out to take the picture with the object still in focus. Now I have a Sigma 18-200mm (with a Canon 600D) and that ...
6
votes
3answers
8k views

How can I get correct focus on the moon or stars with my DSLR? [duplicate]

Possible Duplicate: How to nail focus for DSLR astrophotography? I don't know if D5100 is right camera for this kind of stuff, but I would like to shoot night sky covering moon, stars and ...
4
votes
2answers
121 views

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?
4
votes
2answers
1k views

Is it normal for focal length to change while focusing?

When I change the focus distance on my Pentax 55-300mm lens, the focal length appears to change. More specifically, the lens appears to zoom in as I focus towards the minimum focusing distance. This ...
2
votes
1answer
362 views

Why do some lenses focus past infinity?

On the kit 18-55 lens that came with my Nikon D5100 I have noticed that when trying to focus on infinity for shots in dark conditions (star-trails, etc) the lense tends to move past infinity out of ...
1
vote
1answer
127 views

Focus in night photography

Another question related to the Olympus OMD EM5. I bought this camera to replace my Nikon D90 and I'm very satisfied with it. However, I find very hard to do the focus at night. With the Nikon D90, ...
13
votes
7answers
641 views

How do I get proper focus when photographing lightning strikes?

I've been lucky to have the opportunity to photograph several large thunderstorms in Colorado recently, however I ran into a couple issues. The first issue I've run into is getting proper focus. As a ...
5
votes
1answer
18k views

What is the difference between Al Focus and Al Servo autofocus modes?

Recently I bought a Canon 60D and I am uncertain about when and how to use/activate the Al Focus and Al Servo functions. I understand the One Shot autofocus function for still subjects. You press ...
11
votes
6answers
6k views

How can I get everything in focus?

I have a Canon 550D with 70-200 f4 and 50mm prime lenses. Although the camera has built-in 9 focal points, I sometimes face a strange problem. Here's a sample photo: In reference to the above pic, ...
7
votes
4answers
724 views

Which is better - autofocus and recompose vs. manual focus?

In some occasions autofocus doesn't focus what I intend it to. What is the better option - to use autofocus, focus what I want and recompose, or use manual focus in that situation?
5
votes
3answers
625 views

I'm having trouble getting sharp pictures while shooting a concert from a press pass location

I am a bit of a noob when it comes to photography. But I recently got the opportunity to shoot John Mayer this past weekend in Wisconsin. Upon getting home, I noticed the pictures weren't as sharp ...
4
votes
5answers
721 views

How could I achieve stock quality sharpness?

I am using Canon 600d equipped with 18-55mm kit lens and also I bought 50mm 1.8. I am trying to take pin sharp pictures to upload them for sale.I am shooting still objects and models time to time. I ...