For those of you who are pretty new to this, depth-of-field, aperture, and f-stops are all really closely related (in case you’re wondering what terms this tutorial entails).
From what I’ve seen, most people don’t learn about this because the camera takes care of it for you nowadays. In general you don’t set the aperture on the lens, you do it on the DSLR itself. I thought it might be helpful to give a quick-and-dirty rundown on how it works, because this visual always made it so much easier for me. For all my photography classes back in the 90s we used manual SLRs and a lot of stuff was trial-and-error because you couldn’t look at the screen right after you took a photo - you didn’t find out how your pics came out until you developed the film. I notice a lot of people asking about depth of field and aperture, and it occurred to me that a lot of lenses don’t have these handy little ticks on them anymore…
If you look at this image you’ll see several things.
Notice it has feet and meters listed. Where they line up with that orange vertical line below them is where the focus lies, so in this case it’s right at 15 feet, just under 5 meters.
Near the back of the lens (bottom of the pic), notice the numbers 1.4, 2, 2.8, 4, 5.6, 8, 11 and 16. Those are f-stop values. On a lens like this, you would turn that ring until one of them lines up with the orange vertical line. In this case, the f-stop is between 2.8 and 4 right now. The number is small, but that means the aperture is large (a larger opening).
Okay! Now that we know what these numbers stand for, let’s tackle them one by one.
The feet/meters are easy enough. In this case, anything in the shot that is 15 feet away will be crisp. When you turn your focal ring, you’re lining up where you want your focal point to be. So if you want everything at 5 feet to be crisp, you’d turn it so that the 5 (and therefore 1.5 meters) will be lined up above the orange line. If you want everything at “infinity” (like if you were taking a shot of a landscape) to be crisp, you’d move it so the infinity symbol would be lined up above the orange line.
As far as aperture goes, as I mentioned, a smaller NUMBER means a larger APERTURE (the hole that light comes in through). You would read it as “f/2” or “f/16”. Confusing? Think of it like this - you’re reading the denominator of the fraction. For example, 1/2 is larger than 1/16, right? We’re just looking at that bottom number when we list f-stops. Because 1/2 is larger than 1/16, f/2 is a larger aperture than f/16.
When we talk about depth-of-field we’re talking about how much of the shot is in focus. A small DOF means that only the parts of the subject that are at a particular range of focus will be crisp. A large DOF means that parts of the subject that are much closer or farther away will still be in focus. For a small DOF you’d use a large aperture - more light coming in around that focal point will make the image fuzzy where it’s not directly being focused. If you want a large DOF you use a small aperture - it only lets in a small amount of light so everything will be sharp, you don’t have light from other angles interfering.
Now, how does all this tie in to those numbers on either side of the orange line? Well, here’s where lenses like this are super-handy, and if you remember what this one looks like, hopefully it will help you while you’re shooting.
Look at that orange vertical line again and you’ll see identical numbers on either side - 4, 8, 11, and 16. Notice that they are identical to some of the aperture values I listed, that are at the back of the lens. It’s not a coincidence!
Let’s say this person wants to take a shot with a very small DOF so that only the subject will be in focus, but everything else will be blurry. Small DOF = small f-stop = large aperture, right? In the picture above, it’s already set to a fairly small f-stop of just less than 4, so that’s handy for the purposes of this illustration. Look again at those numbers around the orange line, and find the 4 on either side, and notice that they also line up with the feet/meters listed. The one on the left is at about 13 feet, and the one on the right is at about 18 feet. That means that anything in that range will basically be in focus, and anything outside that range (less than 13 feet but more than 18 feet) will be out of focus.
Let’s say that we wanted to get a photo of something at 5 feet away. Since I don’t have a picture of a lens with 5 feet as the focal point, imagine with me that we’ve turned this one so the white 5 is above the orange line. See how the feet are much farther apart in that range? If you look back around that orange line and look at where those two 4’s would line up, they’d be somewhere between the 4 and 5 on the left, and between the 5 and 7 on the right - probably about 4.75 feet and 5.5 feet. If you were focusing on something 5 feet away, with an f-stop of f/4, everything between 4.75-5.5 feet would be in focus, and anything closer or farther would not. That’s not a very big range. When you take a photo using similar values, you’re going to get that lovely thing we call bokeh if your background is far enough away.
Okay, now let’s say we wanted a very large DOF. Large DOF = large f-stop = small aperture. So we’d turn that aperture ring at the back of the lens to 16. Now, we still have 15 feet as our focal point, but our DOF is going to be larger. Notice the two 16’s around that vertical line. Where those line up to the feet/meters is what will be in focus. So in this case, anything between about 8.5 feet and infinity will be in focus. You’d use a large DOF for something like landscape photography - you’d want, say, the mountain and the lake in front of it and the sky and the grass close to you to be in focus, not just parts of it.
More lenses, to get the feel of it:
On this one, we’re focusing on something just under 5 feet away, about 1.5 meters. The aperture is set to an f-stop of 11 (notice the dot above the 11 on the bottom section). Now look at that top part again and find the two 11’s on either side of the thick white line. They line up at almost exactly 1 meter and 2 meters. That means anything that is between 1-2 meters away from you will be in focus, and anything closer or farther away will not.
Okay, on this one if you look above the red dot you’ll see we’re focusing at 10m/30ft - a pretty good distance away. We have an aperture of f/8 (look below the red dot). When we find the two 8’s on either side of the red dot, we see that they line up with 3m/10ft and… well, anything to the left of the infinity symbol is still infinity. So anything closer than 10ft will be out of focus, but everything past that will be in focus.
This one’s a little harder to follow because they use a comma instead of a period (and those numbers are really smushed together, but they’re 16, 11, 8, 5.6, 4, 2.8, and 1.8), and it doesn’t have feet listed, but it still works the same way. We’re focusing at just over 3m. Our aperture is between 2.8-4. We’ll go with the 4 for this one just because it’s listed, and see that the 4’s on either side of the red line are at just under 3m, and just under 5m. So anything closer than 3m and anything farther than about 4.5m will be out of focus, and anything between 3m-4.5m will be in focus.
When I take pics, I try to imagine a lens like these, and then it’s pretty easy to remember that a small f-stop number means small DOF, and a high f-stop number means large DOF.
One way to look at this is to turn the lens 90 degrees so that the low feet/meters are closest to you, and the infinity symbol is away from you. When you look at the apertures around that middle line, you can see what distances will be in focus. So let’s say you have a subject that’s standing 10 feet from you. Your focus ring will be turned so that 10ft will be above the vertical line, right? If you have a low aperture (high number) then almost everything in your frame will be in focus. If you have a high aperture (low number) then everything from, let’s say, 8ft to 12ft away from you will be in focus.
So if you have your subject leaning on brick wall, that wall will be in focus in either case because it’s within the DOF. If you have them standing 10 feet away from the brick wall though (so the subject is 10ft from you but the wall is 20ft from you), then the wall will be in focus if you have a low aperture (high number) but it will be blurry if you have a high aperture (low number).
I really recommend that you try a few things with your camera. Find a person that will go with you where there is a solid background of some sort that you can move different distances from; even a house wall is fine. Make sure that you are only keeping your focus on the subject, not on the wall.
Take one picture with them standing against the wall, using a low aperture, and one using a high aperture.
Take one with them standing 5ft from the wall, using a low aperture, and one using a high aperture.
Take one with them standing 10ft from the wall, using a low aperture, and one using a high aperture.
Bring those pictures up side-by-side on your computer and compare what they look like and note your settings in each. You should notice a difference - the ones with low aperture will have more in focus, and the ones with high aperture will have blurriness in the background.
Handy image from foodrepublik.com:
The histogram shows how many pixels you have at every level of gray. Look at it as a bunch of lines standing next to each other - it’s a bar graph. The info here lines up to the gradient below (called Output Levels).
See how on the left-hand side, there are almost no pixels at 100% gray (black), but there are a whole lot at about 90% gray? That means the darkest parts of this photo are about 90% gray.
And on the right-hand side, there are almost no pixels at 0% gray (white) but we start getting some at about 15% gray. That means the lightest parts of this photo are about 15% gray.
That’s really muddy - we only have from 90% to 15% here. You want to have the full range from 100% to 0%, black to white (depending on your editing style).
And now for the adjusted histogram…
This is the same image as in the original post, after I adjusted the sliders. This is the part people usually have a little trouble understanding, so hopefully I’m thorough with this.
Notice that I’ve moved where it reads “100% gray” “75% gray” etc.
I’ve dragged up the left-hand slider to where the graph spikes - it was showing me that the darkest pixels I have fell at about 90% gray, right? By dragging my slider up to that mark, I am telling Photoshop that I want it to make those pixels my new 100% gray mark (black), and to adjust all the other pixels in the photo along with it (everything will become a little darker because we’re basically compressing the graph - everything that was 90% is now 100% black, everything that was 80% is more like 90% black, 70% is more like 77% black, etc.).
I’ve dragged down the right-hand slider to where I start seeing that there are more pixels - it was showing me that the lightest pixels I have fell at about 15% gray. By dragging my slider down to that mark, I am telling Photoshop that I want it to make those pixels my new 0% gray mark (white), and to adjust all the other pixels in the photo along with it (now everything will become a little *lighter* - everything that was 15% gray is now 0% gray, everything that was 25% gray is now about 10% gray, etc.).
Finally, I’ve dragged down the middle slider to where I’d like the 50% grays to be. When I moved the other two sliders, the middle one automatically moved to where Photoshop thinks middle gray should be. I felt that it was too dark, so I moved it to the left. That means I’m telling Photoshop that I want everything at about 65% gray to look like a 50% gray, and to adjust everything else accordingly. So not only can I tell it that I want white whites and black blacks, I can also tell it how dark I want the midranges to be.
One more easy way you can see if it’s muddy is to use your eyedropper tool in conjunction with the Info window. With your grayscale image open, notice that when you hover the eyedropper over any part of the photo, it shows you a value for “K:” in the upper left on the Info window. “K” stands for black (CMYK is Cyan Magenta Yellow blacK for example - it’s labeled that to keep it separate from Blue as in RGB, Red Green Blue). So when you hover over a light part, that number will be low - 10% gray is pretty light, for example. When you hover over a dark part, the number will be high - 90% gray is pretty dark. It changes automatically as you move your eyedropper around the photo, you don’t even have to click - pretty handy!
So what you want to do is find the lightest part of your image and hover over that. In the case above, that would be the little flower on her shirt. The dropper shows that it’s around 5% gray - fairly light but not quite white. But that’s just one little tiny area - I don’t want JUST that part to be light, so I’m going to choose a larger area as my sample - her diaper or the lightest part of her arm. The info window tells me that’s around 15-20%. Hey, notice my histogram showed me that’s where my lightest grays are falling! It’s not a coincidence!
Now I want to find out what the darkest parts of my photo are - the trees in the background are perfect for that because it’s a nice big sample area. The darkest I find on there is 93% but it’s mostly around 90% - again, that matches up to what we found on the histogram!
So now with just the eyedropper and the info window, we’ve found out the same info that the histogram told us - my darkest grays are about 90% on average, and my lightest grays are about 15% on average. Just by hovering around like that, we can still tell our image is pretty muddy because there are hardly any areas with lower than 5% gray or higher than 90% gray.
Before you get mad at people who “cut” in front of you in a traffic jam, while you’re patiently (ish) waiting much farther back because you did the “right” thing and merged earlier… please realize that you’re actually contributing to the problem! The actual, proper way to merge is to wait until your lane runs out and then merge. This is not even just an opinion, it’s actually the way traffic engineers expect you to behave, and backed up by the DOT. There are some good reasons behind this! Here’s one of them.
The concept behind the zipper merge is not just to make things fair for everyone; it actually minimizes the congestion by opening up turns for people farther back in line. Notice that car 6, the green one, is unable to reach the exit in the first example. That’s one extra car that doesn’t need to be in line, but is still stuck where he is.
In the zipper merge, by waiting until the merge point to move over, you make certain that the line of cars is actually shorter, allowing more room to open up for people to turn. The length of traffic backup can be reduced by as much as 40%!
“When most drivers see the first ‘lane closed ahead’ sign in a work zone, they slow too quickly and move to the lane that will continue through the construction area. This driving behavior can lead to unexpected and dangerous lane switching, serious crashes and road rage.
Zipper merging, however, benefits individual drivers as well as the public at large. Research shows that these dangers decrease when motorists use both lanes until reaching the defined merge area and then alternate in ‘zipper’ fashion into the open lane.”
Everyone keeps calling this thing Potato Jesus and I can’t help but feel like they’re missing the obvious. So I present to you… Brutus Jesus.
After the Introverts design I made blew up so quickly, someone created a similar list for Extroverts. Working with her, we came up with this companion design. Both are available for purchase through my Zazzle store; t-shirts should be available soon. I hope you enjoy!
From this discussion: “The awesome part about being a good photoshopper is I can make a terrible photo look a lot better and you can’t even tell that I ‘shopped it. The horrible part about being a good photoshopper is I can make a terrible photo look a lot better and nobody will ever know that it was originally a terrible photo. Betta recognize. #whyyesiammodestwhydoyouask”
Straightened image, adjusted perspective, and recropped.
Duplicated and flipped right side of building onto left, blended.
Removed tree shadow from parking lot.
Duplicated and flipped bushes from right side of building onto left, cloned areas as necessary, blended.
Cloned out truck.
Cloned out hose.
Added a high pass layer to sharpen, radius 1.9%, set to overlay at 50% opacity.
Added a levels layer, brightening the image overall, masking out the sky so it wouldn’t wash out.
Added a saturation layer, pulling it up to +9.