Choosing the aperture

[maxpower2001]

Hi everybody,

I would say I already know most of the photography basics, I'm not really a beginner. BUT: I'm still struggling with one thing: Choosing an aperture.

I'm aware how the basics work:

• small aperture number: Faster shutter speed and shallow depth of field. Soft images, depending on the lens.
• big aperture number: Wide dof. Potentially less sharp images due to diffraction.
• in between: Usually the sharpest images. Somewhat shallow or not dof.

When I'm out with my camera I have it set to aperture priority so the camera only sets shutter speed and maybe ISO. I understand most photographers do it that way.
Since I really like photos with a narrow dof I usually set the camera/lens to f/2.8.

My (many many) questions now are:

• How would you/do you choose your aperture?
• Do you almost never use your lens wide open because you (probably) don't get the sharpest image? If so: did you just test what's the sharpest image?
• If you use a prime lens like the 50mm f/1.4 which aperture do you use to get a narrow dof? Since there's a kinda wide range of apertures which lead to a narrow dof (1.4, 1.8, 2, 2.2, 2.8,...).
• Or do you "know" which aperture is best for the current situation?
• Do you make a lot of pictures and compare later?
• What if you have to be quick? If I want to take a foto of two persons and I want both to be in focus but still separated from the background, which aperture should I use?
• If I don't really need a narrow dof (like when the object doesn't have depth, like a wall), which aperture should I use?
• If I want a wide dof, which aperture should I use?

A lot of questions, I'm sorry about that. But maybe it helps to understand my "problem"

Thanks a lot in advance!

Regards
Max

 

[runnah]

I can't say which aperture to use because every situation is different. The best thing I would say to do is to shoot the same subject in Aperture priority mode and go up and down the range and see what the results are at each f/stop. By doing this you should gain an understanding of the the various f/stops affect the final result.

 

[amolitor]

Not everyone uses aperture priority, but it's pretty common. Here's my approach:

- if I am shooting with plenty of light, I set to around f/5.6 (or whatever I think my lens performs best at).
- if I am shooting when it's dark, I'll push down to f/2.8 or so

That's where I start. Then there are a couple things that might happen:

Shutter speed problems:
- If it's too bright, my camera might complain that it hasn't got a fast enough shutter speed, so I will adjust aperture down (to a bigger number) until the camera says it's OK.
- If it's too dark, and the camera is picking a shutter speed I know I cannot hand-hold at or which is otherwise too slow, I will open up until the shutter speed is OK (or until I am all the way open).

Depth of field issues:
- A need for more depth of field. If I am shooting something and want massive depth of field for some reason, I will stop down. Usually f/8 or f/11, but sometimes more if I think it needs it.
- A need for less depth of field, if I want to isolate something from the background better, I will open up. Usually to about f/2.8 or so.

And that's about all I do. If I have shutter speed problems AND depth of field problems, I hope they're pointing me the same way. If they're not, then I have a substantial photographic problem, and I probably have to start fooling with ISO or something.

 

[Overread17 5]

Knowing what aperture to use is partly experimentation and partly experience. If you want you can also get technical with depth of field calculators (there are loads around to use, even aps for mobile devices).

Often as not the aperture is partly selected by the situation as well, the light you are in combined with the subject can often mean that the required shutter speed and your own ISO demands will limit your usable aperture range. In addition never be afraid to experiment or take a selection of different shots at different apertures. You are no less a photographer for doing so and sometimes you might just get a far superior shot just by experimenting a little.

Experience and shooting more will give you more of an eye for both what the apertures does, but also for what your own visual style is and what you "like" to see in a photo yourself. This latter point often means that there isn't just any one working method or answer for selecting an aperture because different people will visualise a scene very differently.

You will also notice that the more you attempt to pre-visualise a scene and shot the easier you'll find selecting the aperture as the depth of field and background blurring will start to become superior to just the base argument of "well what's sharpest). I'd also encourage you to look into and read up on sharpening processes so that you can use a wider range of apertures without feeling as limited by the wide open softness and diffraction limit points (they are still important concepts, diffraction especailly as it can become very strong, but with proper sharpening, resizing and output sharpening you'll fast find that you can work with a range of apertures and still get good shots).

 

[Derrel]

And I thought it was f/11 with chicken and fish; f/2.8 with beef and other red meats; and f/5.6 with shellfish. Huh...

With telephoto lenses of 135mm to 300mm in length, I like to keep the shutter speed up and out of the danger zone if possible; I find that a "small" amount of stopping down from wide-open gives just a little tiny bit of focusing error protection; so for example, instead of f/2.8, I would usually rather be at f/3.2, or more often f/3.5, or actually f/4. These wider f/stops often necessitate elevating the ISO to 320,400,500,or 640 at many times of the day.

With lower-magnification focal lengths, stuff in the short range, f/4 to f5.6 are common f/stops for me. If DOF is paramount, f/9,10,11,13, whatever is needed.

Medium-length lenses, like long normals (60mm,70,85-105mm) are the focal lengths where DOF isolation starts to be an easy task, so f/3.2 to f/4.8 are my favored f/stops for people. For landscapes, you'll usually need to use longer normals to short- and medium-tele lengths stopped down to f/8 to f/16 if youi want deeper DOF, and even then, you'll usually have at least some foreground or background area that falls outside the DOF range; unless, of course, you compose to exclude the OOF areas.

 

[hirejn]

Hi everybody,

I would say I already know most of the photography basics, I'm not really a beginner. BUT: I'm still struggling with one thing: Choosing an aperture.

• How would you/do you choose your aperture?
• Do you almost never use your lens wide open because you (probably) don't get the sharpest image? If so: did you just test what's the sharpest image?
• If you use a prime lens like the 50mm f/1.4 which aperture do you use to get a narrow dof? Since there's a kinda wide range of apertures which lead to a narrow dof (1.4, 1.8, 2, 2.2, 2.8,...).
• Or do you "know" which aperture is best for the current situation?
• Do you make a lot of pictures and compare later?
• What if you have to be quick? If I want to take a foto of two persons and I want both to be in focus but still separated from the background, which aperture should I use?
• If I don't really need a narrow dof (like when the object doesn't have depth, like a wall), which aperture should I use?
• If I want a wide dof, which aperture should I use?

There's no one answer. I know the rules, but because I know them I know when I'm breaking them and why. To let a rule stop me from taking a photograph I believe is good would be utterly ridiculous. Therefore, if I want to shoot wide open, I shoot wide open. If I want to shoot at f/22, I shoot at f/22. What determines that is the look and feel I want in the image, and it's limited by mechanics. For example, if I know I want great DOF but a narrow aperture won't give me the shutter speed I need to hold the camera or freeze action, I sacrifice a bit of DOF to get a sharp shot. I also know that you don't always need f/16 for sharpness. Many landscapes can be held sharp at about f/5.6, and silhouettes at wide open. I process the scene visually and emotionally, and in my head there's no such thing as a bad aperture. There's only what I think is right for the shot.

Knowing the basics and mastering them are two different things. If you understand DOF, you understand the limitations of aperture. You can't always hold everything in focus even at f/5,000. If two people must be in focus, but they're on very different focal planes, and you want the background to be blurred, that's not always possible. If the people are on the same focal plane, the same distance to the sensor, then a relatively wide aperture of about f/4 can hold them while blurring out the background. But it also depends on how close the background is. This is a dance you do and knowing the right aperture becomes instinctive with practice.

In your wall example, if the camera plane is parallel to the surface, you don't need to close down huge. Something like 5.6 to 8 will be plenty. The same principle applies in landscapes. If you have a distant mountain, you don't need f/22 to bring it in. The thing is so far away you can nail it with 5.6 tack sharp. But foreground objects also play a role. It's about choices, and nobody can tell you ahead of time what aperture you must use.

I don't take a lot of pictures and compare apertures because technique isn't a mystery to me and I'll know from the LCD whether I got the image or not. The main thing I check for is focus. If my focus is good, I trust my other choices and I don't need to analyze or chimp. If you're uncertain about your aperture, use the depth of field preview button to see the effect of the aperture before taking the shot. When doing HDR, changing the aperture will throw off the image. What will help you is experience.

 

[DiskoJoe]

This is totally a beginner question. You say you like to shoot at f2.8 alot. Why? What are you shooting? The subject would determine what aperture you would want to use. For portraits you typically use a large aperture since you just need the subject in focus and most people like the background blurry. But for landscape you would want the whole scene in focus so a smaller aperture would be ideal.

 

[table1349]

How would you/do you choose your aperture?

I choose the aperture I need to get the look that I want.

Do you almost never use your lens wide open because you (probably) don't get the sharpest image? If so: did you just test what's the sharpest image?

See Answer above.

If you use a prime lens like the 50mm f/1.4 which aperture do you use to get a narrow dof? Since there's a kinda wide range of apertures which lead to a narrow dof (1.4, 1.8, 2, 2.2, 2.8,...).

See answer above.

Or do you "know" which aperture is best for the current situation?

I know what look I am wanting and choose the settings to achieve that look.

Do you make a lot of pictures and compare later?

No

What if you have to be quick? If I want to take a foto of two persons and I want both to be in focus but still separated from the background, which aperture should I use?

The aperture that gives you sufficient DOF to have both in focus.

If I don't really need a narrow dof (like when the object doesn't have depth, like a wall), which aperture should I use?

The one that gives you the look you want.

If I want a wide dof, which aperture should I use?

The one that gives you the necessary DOF you need/want.


http://www.cambridgeincolour.com/tutorials/camera-exposure.htm
http://www.cambridgeincolour.com/tutorials/depth-of-field.htm
http://www.cambridgeincolour.com/tutorials/camera-lenses.htm

The whole series: http://www.cambridgeincolour.com/learn-photography-concepts.htm

DOF Calculator: http://www.dofmaster.com/dofjs.html

 

[maxpower2001]

Thanks everyone, you already help me a lot to understand this topic more. I also really liked the mini how-tos. Not to do it exactly the same, but it's always nice to know how other people work compared to oneself.

This is totally a beginner question. You say you like to shoot at f2.8 alot. Why? What are you shooting? The subject would determine what aperture you would want to use. For portraits you typically use a large aperture since you just need the subject in focus and most people like the background blurry. But for landscape you would want the whole scene in focus so a smaller aperture would be ideal.

I like to shoot at f/2.8 because most subjects I shoot, demand (imho) a shallow dof. I just like the separation of what I'm shooting to the rest in the picture. Also, that always leaves me with fast shutter speeds, in case there's less light or I go indoors. I'm not a huge landscape photographer. But every time I did shoot "landscapes" I just kept using the f/2.8 aperture. I'm not dissatisfied with my pictures but since I know that it might be possible to improve my results and I'm always eager to learn new things/get better in what I do/get rid of bad habits, I was seeking for some advice by people more experiences than me.

Thanks again to all of you

 

[maxpower2001]

Haha, great answers gryphonslair99. Kinda what I was thinking but I wanted to make sure

How would you/do you choose your aperture?

I choose the aperture I need to get the look that I want.

And how do I know which aperture get's the look that I want? Experience?

Do you make a lot of pictures and compare later?

No

Did you ever?

If you use a prime lens like the 50mm f/1.4 which aperture do you use to get a narrow dof? Since there's a kinda wide range of apertures which lead to a narrow dof (1.4, 1.8, 2, 2.2, 2.8,...).

See answer above.​

The problem I'm having: I kinda know what look I'm getting with f/1.4-2.8 vs. f/5.6-8 etc. But in between these ranges it feels like random bingo to choose one. It works but I thought there might be something better than bingo. Also the subjects usually are different every time, so testing the look beforehand is difficult.

 

[table1349]

Haha, great answers gryphonslair99. Kinda what I was thinking but I wanted to make sure

How would you/do you choose your aperture?

I choose the aperture I need to get the look that I want.

And how do I know which aperture get's the look that I want? Experience?


Did you ever?

If you use a prime lens like the 50mm f/1.4 which aperture do you use to get a narrow dof? Since there's a kinda wide range of apertures which lead to a narrow dof (1.4, 1.8, 2, 2.2, 2.8,...).

See answer above.​

The problem I'm having: I kinda know what look I'm getting with f/1.4-2.8 vs. f/5.6-8 etc. But in between these ranges it feels like random bingo to choose one. It works but I thought there might be something better than bingo. Also the subjects usually are different every time, so testing the look beforehand is difficult.

Now you are seeing the difference between understanding the idea's behind the basics of photography and actually understanding the basics of photography. If you truly understand the basics you can put that understanding to use.


I love the sciences, especially the physical sciences. I watch a lot of Discovery Channel, Science Channel, History Channel, etc. I also have read several of Einstein's books, a couple of Micho Kaku's books, a few of Hawking's books and am currently reading one written by Neil deGrasse Tyson. I also have read the writings of the likes of Tesla, Planck and Bohr to name a few.

With that said, I understand the basic principles behind Physics, Quantum Physics, Quantum Mechanics, etc. I however am in no way a Physicist, Quantum physicist or any thing remotely close. That take the ability to possess, use and expound upon that knowledge, which I can not do.

Photography is not as complex. It does however take time, effort and patience to learn the basics to the point that you can actually put that knowledge to use. I have been involved in photography for 45+ years now and I am still learning. Good Luck with your journey.

 

[KmH]

Yep. Experience.
I too love the physical sciences and how those relate to photography is a large part of photography's appeal to me. I was surprised how much I enjoyed (and was good at) the artistic aspects of doing photography.
I learned photography back when manual mode was the only choice. Choosing a lens aperture and it's associated DoF has long been second nature and doesn't really require much in the way of conscious thought.

Having a very good, intuitive understanding of how lens aperture, lens focal length, and point of focus distance effect DoF really helps.

You mentioned "really need a narrow dof". DoF is depth-of-field so I think of it in terms of deep or shallow, rather than narrow or wide.
In other words I think of DoF in terms of being a range of distance from the camera to the background.

Whenever I see/hear someone use the terms narrow or wide when discussing DoF I get the impression they don't yet have a good grasp of how DoF really works.

I have said before that DoF is likely the most difficult fundamental technical photography concept those new to doing photography have to learn to deal with.

 

[maxpower2001]

I don't want to state that I truly know how dof works at all. But about what you just mentioned: narrow vs. shallow.. I'm not English, I'm German Even though I would say, my English is quite good, the narrow vs. shallow problem is probably more due to my (less than perfect) vocabulary than my dof knowledge

Thanks a lot for the comment!

 

[bratkinson]

As I do most of my shooting indoors at church events, and perhaps 40-50% without flash, much of my settings, including aperture, are 'driven' by lighting conditions. Obviously, wide-open or nearly so shooting is a must. For me, my biggest choices are ISO (without too much noise) and shutter speed...fast enough to stop subject motion or do I actually -want- arm/hand motion blur while the subject is talking, etc. Of course, if I want to separate just the subject, wide open...135mm f2 works fantastic for that. When I want more DOF, stop down, slow down the shutter and speed up the ISO.

I don't know whether I'm an 'oddball' in my thinking or not, but I never think: "ISO this, f-stop that, speed such-fast under conditions 1, ISO/f/s xxx under conditions 2..." etc. Unless I simply want to put the camera on "A", there's no way I could shoot under such mind-boggling situations. I've simply learned wider/smaller - faster/slower - what's the highest ISO I can live with? What are the desireable/undesireable results of changing xxxx setting? That's it. What's the histogram show? And make adjustments from there, knowing what I want and that the limits of the equipment may or may not restrict what I can get. Fortunately, over the past few years, I've had the resources to finally upgrade my glass to f4 or faster L glass, and a 5D3 with mind-boggling ISO capabilities. So my choices of settings have fewer restrictions and limitations to deal with. So now I can spend more time thinking/composing my shots without having to make compromises due to equipment limitations.

 

[Dao]

Experience play a major role in here. Without knowing HOW it affect the result, it is just hard to predict the result.

If I going to shoot an insect with my macro lens, I am going to start the f number at f/10 to f/12 with diffused flash. If I am going to shoot a indoor birthday party or events with bounce flash, I will start at f/5.6 to f/8. A dance recital, I will choose a min of 1/200 (of faster) shutter speed and adjust the ISO and aperture to achieve the shutter speed I want. Why I choose that settings? It all based on my own experience.

So I believe after you take photos for a little while, you should know some of your settings as well.