f3, 1/160, ISO 160, 60mm, Shallow Depth-of-Field (No photo editing done, besides the crop on these images to keep it consistent.)
For those of you that know how depth-of-field and aperture (the f-stop numbers) relate, this post is not for you. In fact, many readers here are very competent photographers and this information would be very elementary, but for a portion of you, it may prove most useful. Sometimes a visual example is the best kind, but this post is packed with loads of useful info. And it all started with a reader’s question.
I got an email from a reader the other day who asked,
“I am new to photography with a good camera and a reader of your blog. I have been admiring your photos, especially the closeups with the blurry background. I have been taking all my pictures in Auto Mode and can’t get those out of focus backgrounds. Can you please tell or show me how you do it?” Thanks, Lanni in San Paulo
Well, Lanni, thank you very much for the email and I will do my best to give you one method which will help you to learn your camera in Manual Mode. There are many like you, still using the camera in Auto Mode, and some, having no desire to learn anything but. That is easy to understand too. Keep it simple.
I can see from the rest of your email, you do have a camera that has manual functioning, and it is far better to use it than essentially having an expensive point and shoot.
I could send you to pro sites which could explain depth-of-field, but I will give it a try since you asked, and I can show it rather easily. I will do my best to supplement the photos with simple written information, and explain it as I understand.
First and in case you are not aware, the f-stop number is a ratio of the focal length of the lens to the diameter of the aperture. The definition is the measurement of the aperture setting in a camera lens. It determines how much light is allowed to enter the lens and pass on through to the digital sensor. Its other function is how much in focus a subject is in relationship to what is in front of and behind it, and in this way, effects the depth-of-filed, or blurry background that you asked about.
What people find confusing about f-stop, is that as the numbers for the f-stop get smaller, the aperture (opening) gets wider, or conversely, the numbers increase as the aperture gets smaller. It is an inverse relationship, and is based on the ratio of the focal length of your lens divided by the diameter of the lens opening. If you think about this it is not so hard to understand, but I will spare you the math and keep it simple. Just follow the images. Simply, the smallest numerical f-stop is not the smallest aperture opening. Now with that out-of-the-way…. how to find it.
The camera is said to be ‘wide open’ on its smallest f-stop (lowest numbers). You can set your camera to Manual and find the dial which changes the aperture. You may have to go to the user’s manual if you have never used this before. That dial (Sub-Command Dial) is on the front right of my camera, the dial to set the shutter (Main Command Dial) is on the back right, easy to change without taking your eye off the subject. (For some reason, shutter speed has always been easier for people to understand.) Then you look in the Control Panel to see what f-stop and shutter speed you dialed in or look in the viewfinder. Again, check your user’s manual.
What might be the easiest and less intimidating is to use Aperture Priority Mode. In examples like I am showing with a shallow depth of field (flowers really close to each other), you may have to set the camera lens to manual focus first. The auto focus will jump around and not necessarily focus on the area that you want since the image has so much going on. But it may be the best way you have to understand the objective here because you do not have to dial in a shutter speed, ISO, or even focus.
So try it first, but be aware you may not have in focus just what you want. Once you get a handle on what setting the aperture does, then try all the other fully manual variables. If you have a sizable distance between the foreground and background and a very distinct subject, Aperture Priority Mode is very useful and effective to get those blurry background shots.
In my examples, f3 above, is my most wide open f-stop and one you MIGHT want to use to get your blurry background. Notice I emphasized might. It is based on if your lens can even reach that f-stop, your shutter speed, ISO, and also on personal artistic preference if you go the full manual route. You can have a look at what other f-stop examples produce in my comparison images for the artistic approach. Note the shutter speeds too.
The easiest way to learn this depth-of-field technique, is practice, practice, practice and have your subject positioned as far away from the objects in the background as possible. This makes it much easier to attain, and also makes for your most blurry background.
Unfortunately, in landscape photography, sometimes your subjects are all relativity in the same place like in my example today. So, you have to know how to isolate your subject from the surrounding clutter.
You also did not mention what type of subjects you are photographing, but since you read here, I am guessing it might be flowers or insects. Flowers don’t get up and move, so they will be our subject here today. Again, simple.
f4 1/125 ISO 160
I use Aperture Priority most often shooting wide open landscapes. With the aperture closed down to f22 or greater, there is not much worry on focusing as the foreground to the horizon will be in crisp focus, like below.
I wish you would have said what camera you are using. I use a Nikon so I am discussing the modes on that brand. Here are some shot setup basics:
- The flower grouping was in flat shade and was chosen so only two settings that I changed, aperture and shutter speed, and not sun conditions, would affect the image.
- A busy image was selected to have a subject to isolate. It also will maximize the effect at the smaller f-stop.
In the image progression you will see the background coming into focus.
- I used a prime lens, (one that does not zoom, but has a set focal length), to illustrate how depth-of-field by changing aperture settings and associated shutter speed affects your final image.
- I kept the focal length and ISO constant for two less variables.
- I used a tripod to keep images consistent and keep the camera steady at slower shutter speeds.
Many people have a difficult time visualizing depth-of-field before they push the shutter, and some cameras have a button you can push that gives you an idea beforehand. Check your manual, I bet you have a Depth-Of-Field Preview button. Honestly though, knowing is better than relying on the camera to show you.
You end up with a short-range of focus in the image if you use a wide aperture. You can see even at f5.6 the Veronica is still blurred. It is a fine f-stop for this shot, giving a good amount of information. But an errant sun ray had the nerve to sneak in and brighten my background.
f5.6 1/60 ISO 160
As we close down the aperture to higher numbers, the background starts coming into sharper focus. And the background can become distracting if one wants to highlight a certain bloom. Another thing to notice, the shutter speed is slower at f5.6 in this lighting and we are getting where we cannot hand hold the camera. Of course, this varies by your daylight conditions, and with sunnier conditions, f5.6 is a good number to use pretty often.
f8 1/30 ISO 160
Depth-of-field is going to be primarily affected by a few things:
- The aperture.
- The distance between the subject and the background.
- Where you are positioned in relationship to the subject, see below.
- The lens you are using.
So to get your desired image, simply choose…
f13 1/10 ISO 160
- If you want both near and far objects in your scene in focus use a small aperture or bigger f-stop numbers.
- If you want the soft backgrounds and isolate your subject by letting the background go out of focus, use a large aperture and small f-stop numbers.
- Softening the background with smaller f-stops adds a pleasing quality to a photo, and it serves to eliminate a lot of the distracting elements, so it may be a great choice to make.
f20 1/5 ISO 160
I stopped at f20 because the background is pretty focused in this image. So I guess the purpose of this exercise besides the use of aperture, is also what you want to feature in your image. Is it about the verbena or is it about a grouping of the lavender, verbena, hydrangea, and veronica? Do we have to see everything clearly, or is a certain amount of blur helpful in the strength of what the image is trying to tell?
I hope I helped answer your question Lanni, but, there is so much more to discuss on aperture. My preference is the soft background too, and a little less contrast to the image. I have been including camera settings with my photos but did not realize some may not know what they mean. You also mentioned in your question the photos being closeup, and that leads to another use of depth-of-field.
Zoom Lens 165mm f5 1/60 ISO 160
If you want maximum depth-of-field, use a zoom lens because they allow you to fill up the frame with the subject, and they give the background visual importance. But, you have to be a bit careful with zoom lenses at the wider aperture because distortion of your main subject can occur.
So of the images that I showed, which of the above do you find more appealing? Which conveys the information or story you wish to tell?
Have a look at the really short video to see the image progress from f3, blurry background to f20, sharp background. It adds many more f-stops than I showed in the still images.
f3.8, 1/100, ISO 100 manual with flash 60mm Nikkor Micro ( which really means macro as it is a 1:1 ratio lens, weirdly confusing). This is the same lens as I used in the above examples too.
And what about really close with loads of blur?
One thing to notice about this kind of image, you cannot really even tell what flowers are being photographed this close.
f4.5 1/30 ISO 100, See how a flash makes the image in shadow pop? I also added a polarizing filter, which reduces glare off the raindrops and gives a punch of saturation.
So this kind of depth-of-field is a whole different approach when shooting macros such as this. Notice how very shallow the depth-of-field becomes when the plane of view and focus is so very narrow. Think about the information in the post, what aperture could I have used to get more of the two shots above in focus?
Another good point to make, it matters how close YOU are to your subject. I used the same lens as almost all the images above, and the only thing that moved was me! That is something people often forget about when framing an image, that their feet are one of the best tools they have at their disposal.
Since I have been getting emails requesting me to show how I do some of my photo work, especially really close photos like my bees, I added the tab above called Photography Tips and Thoughts. I will do a post on true macro, like the photo above sometime in the future, for both Lanni and a few others that requested a reply. These are some things that might be useful for beginners that want to go a little beyond. Also, there are five-minute tutorials with some cool things to do with Photoshop in the link above.
Thanks again, Lanni, hope I helped you out. If you need more in-depth, try a few of the professional photographers’ sites. I am a member of NAPP, the Professional Association of Photoshop Professionals and Kelby Training. They are go-to sites for photography and Photoshop. The best of the best teach there. Update, a professional photographer has a post, What is the f-stop number all about? For more to learn… go see filmcamera999.