# How can I show a slope? Even mountain roads appear flat in my photos

During a bicycle trip, I wanted to take a pic to show how sharp the slope was (about 20%). The same applies downhill. See below, the viewer can't really tell whether it is downhill or flat or uphill:

What are your tricks to imply the steepness of a slope?

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I think the sign helps. :) – mattdm May 8 '11 at 16:26

You need to shoot from an angle - if all the trees/signs are in front of you then they will all appear vertical in the image regardless of the slope.

This is actually a well known illusion that gives rise to "gravity hill", a road which slopes downhill but looking head on in the absence of any visual cues the brain interprets it as flat/sloping up, which causes objects to appear to roll uphill!

Photo by fluxn

If you shoot side-on or from an angle there would be a clear difference in the line of the trees and road which would give the viewer the information that the road is sloping.

Here's an extreme example:

The slope is clearly evident when you look at the trees. Note that photo was taken by a friend with my camera, as I'm in it!

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That is a bright suit you have there. – Evan Krall May 8 '11 at 10:27
Interesting! Going out of the road is something I can't easily do when cycling... I guess a first rule would be to at least make sure the horizon is included in the pic. Also, any trick to make the slope appear even sharper than real, or is this impossible? – Nicolas Raoul May 8 '11 at 10:44
Hey @Matt, is that an Acid EVA spacesuit? ;-) – ysap May 8 '11 at 13:28
It's just a regular one piece ski suit, right? – Matt Grum May 8 '11 at 16:06
@Nicolas To make the slope appear even steeper than it is, you'll need to provide the same sort of angle clues. Find a tree, sign, or something else that should be vertical but is tilting towards the slope. Angle your camera so your tree/sign is vertical in the photograph, and make sure there aren't any giveaways (a whole forest of tilted trees in the background, etc.) – Evan Krall May 8 '11 at 22:59

In addition to Matt's answer, if you can until the bottom of the hill is in sight you can also get an idea of slope without shooting from an angle. See, for a not particularly good example, the following taken from Flickr:

Credit: Frans de Wit, cc licensed

This obviously only applies if you're facing downhill.

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The Inception effect. – Evan Krall May 8 '11 at 22:53

Shoot sideways. Certain things are most often vertical, regardless if they are on a slope or not. So, I would shoot the slope at an angle so that you can see the slope and those naturally vertical objects.

In your example, the trees and road-signs should be vertical (although I know in some extremely rare occasions they are not which cause an optical-illusion of sorts), so there should be a non-90-degree angle between the slope of the hill and tree-trunk and road-signs.

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