Plumb vertical lines

A23 Perspective Rule #3

Make vertical lines plumb

This module aims to teach you the tricks needed to make the vertical lines in your shots look perfect.

Here is a quick outline:

Introduction
What causes vertical lines to lean?
How to check if your vertical lines are plumb
How to plumb vertical lines?
Dealing with the unacceptable side-effect

Terms explained

This line "─ " is horizontal

A horizontal line is LEVEL when it's parallel to the horizon.

This line "|" is vertical

A vertical line is PLUMB when it's perpendicular to the horizon = Not leaning = Parallel to your frame sides.

Disclaimer

This module on Making vertical lines plumb is intended only for the most devoted and passionate local guides who wish to make every effort possible to perfect their photography skills. Making all vertical lines plumb might be the most ambitious and intricate skill presented in this tutorial. So feel free to skip ahead to Shooting tips now or anytime if this module gets too complicated.

Below are 3 examples of leaning and plumb vertical limes. If you find the images equally good looking then also please skip ahead to Shooting tips.

This 3rd perspective rule Plumb vertical lines is very simple, but it takes some time and effort to master this specialty. So please be patient and read on - and you will 'get it'! Once you 'get it' you will be able to improve the perspective significantly in most of your shots.

1. Introduction

Easy to spot vertical lines include:

The sides of buildings and storefronts
The sides of windows and doors
Downspouts
Painted vertical lines
Any visible vertical lines

Plumb means:

Not leaning
Straight up and down
True vertical
Parallel to your frame sides
Perpendicular to the horizon.

These 4 vertical lines are far from plumb. Notice how they are further apart at the top? We call these OUTwards leaning lines. Symbolized: \ /.

These 4 vertical lines are also far from plumb. They are closer together at the top. We call these INwards leaning lines. Symbolized: / \.

The easiest way to check if a line is plumb is to compare it to the nearest side of your frame. Is the distance constant up and down? If yes, your line is plumb.

photos.app.goo.gl/ZgzCWCaZakh4f93L9

A perfect example

In this example all the vertical lines are plumb.

Just check the lines visually against the nearest side of the frame.

As in most photos, there are several lines you can check: The sides of the building, sides of the storefront, sides of windows, and doors and here also a downspout.

Google Maps link

photos.app.goo.gl/4vBXvSD6UHfVrV5G8

A very bad example

Notice, the lines on the woodwork to the left. They are nowhere near parallel to the left side of the frame. Also, the lines on the right side are not straight up and down.

Looking at the two sides of the window reveal they are leaning outwards (\ /).

Google Maps link

Turn on your grid-lines

If your camera can show grid-lines on your screen, then, as suggested earlier, please turn them on. These lines are extremely useful as they give you 2 extra vertical lines to compare with when checking for plumbness.

Watch this short video to see some grid-lines.

2. What causes vertical lines to lean?

Tilting does. Tilting is always the problem. Tilting causes vertical lines to lean in photos.

So if you can eliminate the tilt of your camera, your vertical lines will automatically be plumb.

We often unconsciously tilt our camera to fit a building inside the frame or to center a storefront vertically in our shots.

If you can stop the tilt your vertical lines will look perfectly perpendicular to the horizon.

3. How to check if your vertical lines are plumb

Overall, there are two ways to check if your lines are plumb:

A: You can take your eyes off the screen and instead look at how you are holding your camera.

B: Check the vertical lines on your screen against the frame sides or the grid-lines.

A: Look at your camera and use a spirit level

It sounds like a crazy idea. But if you are having trouble with getting your vertical lines plumb this trick can be useful. It is not easy to hold a spirit level to your camera. Preferably you should use a smaller spirit level than the one shown in the two photos below. The spirit level will remind you to check the lines! And the bobbles position will show you which way to tilt.

This is a smaller and more handy spirit level. You can get it from eBay for only 2-3 USD. Find links here.

Holding this kind of spirit level against you phone allows you to quickly check if the tilt is neutral or not.

You can also use an app to check if your camera is plumb and level. Notice the scales on the sides in this short video. I have tested a few apps but none of them works well with the native camera app. But they can be useful when practicing or if you are using a tripod. Search for "camera spirit level" in the App or Play Store to give them a try.

B: Check the vertical lines on your screen against the frame sides or the grid-lines

The second and most obvious way to check if your vertical lines are plumb does not require you to take your eyes off the viewfinder screen. Instead, you eye one or more vertical lines and check if they are parallel to the frame side or the vertical grid-lines.

4. How to plumb vertical lines?

When you have spotted leaning lines, you can just "play" with the tilt. Tilt-up a bit and tilt-down a bit until you see the vertical lines becoming more and more parallel with the frame sides or grid-lines. And stop when the lines line up perfectly. This is super easy.

Try it out. Go practice!

Just "play" with the tilt up and down until your vertical lines are plumb!

Plumb both sides

Don't repeat my mistake. In the beginning, I was very focused on plumbing the nearest side of storefronts and buildings. So much so that I sometimes forgot to check the far side for plumbness. Study the three images below.

The first shot of this beautiful building. Ups, look how the left side is leaning inwards.

So I lined up the left side of the building by rolling the camera clock-wise. As the left side now looks fine the right side is leaning even more. And the building in the background is almost 45 degrees off from being level. Never use Roll to fix vertical lines.

Since moving up to Center height of this tall building was impossible I moved back and used the Zoom+Tilt+Crop-trick to get this much better shot.

Tilting up or down

I had a hard time figuring out when to tilt up and when to tilt down to fix the vertical lines. So the following 5 mnemonic tricks were developed to make this easier for you to remember which way to correct the tilt. They are:

Above=Tilt Up. Below=Tilt Down.
Push the intrusion out.
Spot the big arrow head.
\ / = Up. / \ = Down.
Spot a 'pulled out'-corner.

These trick are explained and illustrated on page Tilting UP or DOWN? Which trick will be most helpful and easy for you to remember?

PS: There is no need to study these tricks if you are OK with always just try tilting up and down to see what kind of tilt makes your vertical lines plumb.

If you need help figuring out when to tilt up and when to tilt down visit these

Mnemonic tricks

You will never be in doubt about how much tilting is needed to make the vertical lines plumb. Just keep adjusting the tilt up and down until the vertical lines are plumb!

5. Dealing with the unacceptable side-effect

Now you know how to check the vertical lines and how to plumb them. But. Yes, there is a catch.

Removing the tilt can cause another problem. The storefront or building might be sliding out the frame so the bottom of the storefront or the top of a building will be missing in your shot. This is really bad. This is an unacceptable side-effect of making the vertical lines plumb.

To deal with this unacceptable side-effect there are 3 solutions available:

Move down
Move up
The Zoom+Tilt+Crop-trick

You need to find the best possible balance between plumbing the vertical lines and keeping the store/building inside the frame.

The optimal height for your camera is always 50% of the height of the storefront/building you are photographing. We call this center height.

The move down-trick

Notice the outwards (\ /) leaning vertical lines in this shot. To fix them you need to tilt up quite a lot. Tilting up will cut off the lower part of this basement shop.

Here the trick is to sit down (get down low) and take the shot from there. The shop windows are about 1.5 meters high. To get this perfect shot you need to move the camera down to the height of about 0.75 meters high. This is the center height.

The move up-trick

This shot is taken from eye height. The building is 2 stories high, so it is no surprise that the sides are leaning inwards.

This shot is taken from 4.5 meters up which is close to center height. Notice all the plumb vertical lines? Also, you can see a bit more of the roof in this shot.

To reach 4.5 meters up I use this monopod with a phone mount and the shown Bluetooth trigger button. I connect the button to my phone and lift my phone up to take the shot. This is the way I can reach the heigth of 4.5 meters. It often takes a few tries to get the angle and framing right. Details on these accessories can be found here.

To carry around a monopod is not very convenient, but it gives opportunities to take shots from unusual angles like in this shot.

Instead of carrying this gear I mostly use the Zoom+Tilt+Crop-trick described below.

The Zoom+Tilt+Crop-trick

When shooting tall building you inevitably tend to tilt up to fit the building in your shot. This causes the vertical lines to lean inwards. If you did not bring gear to get up high or the building is too high you need another trick.

The trick is to walk backward away from the building and or zoom out. This will allow you to tilt down while still keeping the building inside the top half of your frame. Later you remove the unwanted extra from the bottom half of your frame.

This very useful trick is explained and illustrated here.

Please try using this trick.

Use this trick to plumb the sides of taller buildings and basement stores

Zoom+Tilt+Crop-trick

Establishing a new habit

The hardest part is not to fix the lines but to always remember to check the vertical lines.

Therefore try to make it a new habit to always STOP after you have framed a shot. STOP right before you take the shot. You need this break to check the vertical lines and adjust if necessary before you pull the trigger and capture your image.

Start practicing: STOP, CHECK, and ADJUST THE TILT before you take a shot. Always STOP and CHECK.

One day this will become automatic and you will always remember and know by heart how to fix the vertical lines without even thinking about it. But in the beginning, it takes a lot of effort and practice to get this new habit established. The best advice is to practice, practice, and practice some more.

Always STOP, CHECK, and ADJUST the tilt if needed before taking a shot.

Congratulations

Now you know how to make the vertical lines straight up and down. The cheatsheet and the illustration below summarizes how you can improve perspective distortion in your photos while out shooting by tilting and moving.

If you want to test your new skills try taking the quiz called Plumb vertical lines. Can you answer all the 15 questions correctly?

Plumb vertical lines

Snapseed demonstration

There is one last tool you probably will love. Perspective distortion can also be fixed later. You can use an app to artificially squeeze and counter distort your image to make the lines look plumb. It is always better to fix the lines while out shooting, but if it proves impossible using an app can save your shots.

One such app is called Snapseed from Google. See the Snapseed demo here.