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Highlights Long Exposure Photography

Introduction

The second instalment in a short series that condenses some of the most important B&W processing tips I shared over the years and still stand the test of time. The first one, highlighting the most important tips for better Black and White photography can be found here.

Perhaps the topic I wrote about the most over the past 15 years is on Long exposure photography. Even though this topic has brought hundreds of thousands of viewers in the first 5 years, it also has gradually become an overused and misunderstood part of photography. 

The reason in part is that the Internet is now flooded with long exposure tutorials. Most of it is redundant, and even the most complete tutorials don’t cover what I have covered in the last version of my tutorial, published 9 years ago. Even though the number of viewers today is just a tiny fraction of what it was 10 years ago, I believe it still stands the test of time. It is still the most detailed free tutorial and is still head and shoulders above the majority of newer tutorials out there in terms of quality. Of course, specific gear recommendations have been outdated now. That is not enough reason for me to update it again. 

Long Exposure Photography Highlights

So let me highlight the most important elements of the very detailed tutorial in this article while referring to the original tutorial for more background and other relevant information.

First, a definition of what long exposure photography entails. And no, it is not an exposure with a specific duration of an arbitrary time as most tutorials would claim.

Therefore, it’s not the duration of the exposure that qualifies it as a long-exposure photograph, but the intention of capturing moving objects with longer exposure times than necessary that makes it a long-exposure photograph.

The phrase “[…]using longer exposure times than needed to obtain a correctly exposed photograph[…]” contains the key. So if a photo, to be correctly exposed, needs an exposure time of 1/4000s and with a 6-stop ND filter it would result in 1/60s then it still is a long-exposure photograph, even though according to many ‘experts’ it would not be a long exposure photograph when they state it needs to be longer than let’s say an arbitrary 1 second.

Long Exposure and its effects on moving subjects

I’m going to keep it simple here. You can use long exposure techniques for either water, skies, or crowds/traffic. Water can look like ice with a smooth surface, clouds can look like streaks or soft transparent veils, and people and traffic can be invisible or look like ghosts. There are other variations where water can look less silky but with directional streams using shorter exposures, and clouds can look like a whiteout sky. Just try the different exposures with different ND filters.

The following table still is a good guide.

Exposure Time TMoving WaterMoving Clouds – Camera Pointed Straight Forward To HorizonMoving Clouds – Camera Pointed To The SkyMoving People And Traffic
Short: T – Less Than 30s– Visible texture and details in the water– Strong sense of water flowing and its direction– Richer in contrast (details still visible)– Recommended for very fast flowing water like water falls and for normal water flow if you want to create a dynamic looking water– Slightly distorted clouds, depending on how fast they are, but under normal conditions they’re still recognizable with softer, blurred edges, softer contrast and less details.– Clouds tend to be more distorted and form the beginning of short streaks of clouds under average conditions. There are less details– Transparent shapes of people and of traffic are visible with some details– Ghostly effect of people and traffic– Visible sense of movement– Light trails will dominate the scene at night in traffic
Medium: T – Between 30s And 3m– Less to no texture and details in the water– No sense of direction or movement of the water– Less contrast in the water– Depending on how fast the water flows, the water will look smooth and flat like ice– Less recommended for water falls, recommended for normally flowing water to create a calm and minimalistic look– Soft, blurry clouds with even less to no details, but clouds are still recognizable– Even less details, hard and contrasty streaks of clouds, distorted shape– Shapes of people and traffic are less to not visible, depending on the speed of people/traffic moving. Static people/traffic will be better visible– Ghosting effect is more blurry and softer, no details visible– Streaks of lines and colors in traffic during daytime, at night light trails will dominate the scene in traffic and appear longer– Still visible sense of movement but to a lesser extent, again, depending on the speed of moving objects/people
Long: T – More Than 3m– No texture or details at all in the water– Very soft to no contrasts in the water, very flat and smooth looking– Not recommended for water falls but recommended for any other type of very fast flowing water to make it look smooth, calm and minimalistic– Ideal to create an ‘ethereal’ look-Very soft looking clouds, blurry, dreamlike and ethereal. Less recognizable shapes and in some cases they even form soft streaks of clouds– No details, softer and longer, almost transparent streaks of clouds: ethereal.– People and traffic will completely disappear only leaving some traces of ghosting effects.– At night light trails will still be visible depending on the amount of traffic but appear more as ghosting effects, transparent.– Public areas will appear empty

Below is an example with water that looks smooth and silky and with a sky that has no details and looks like a veil due to the longer exposure time of over several minutes.

Essential gear for long exposure photography

What do you need?

  • A camera with bulb setting – any DSLR or mirrorless these days has that setting albeit under different names.
  • A remote control so you don’t need to depress the shutter button continuously
  • A tripod to hold your camera perfectly still for a longer time
  • A set of ND filters. I recommend having a 6-stop and a 10-stop filter. You can use it separately or stacked up to have 16 stops at the most. Longer is very rarely needed.
  • Duct tape and a dark cloth to cover up the camera and the lenses where light might leak through. Light leakage is a big issue in long-exposure photography! Especially with very wide-angle lenses and even worse with tilt-shift lenses. It’s the most common issue in long-exposure photography. How to prevent it: cover up everything. See more on that here

How to use it

  1. COMPOSE THE SHOT WITHOUT THE ND FILTER.
  2. SET YOUR CAMERA TO APERTURE PRIORITY
  3. TAKE A TEST SHOT AND TAKE A METER READING WITHOUT THE ND FILTER.
  4. USE THAT TIME AS THE TIME TO CALCULATE THE LONG EXPOSURE TIME DEPENDING ON THE FILTER DENSITY
  5. SWITCH OFF AUTOFOCUS AND SET THE CAMERA TO BULB MODE
  6. MOUNT THE ND FILTERS
  7. CALCULATE THE EXPOSURE TIME
  8. TAKE THE SHOT

For a detailed explanation for the individual steps have a look here 

Calculating the exposure time

For calculating the exposure times there are several apps or just use the chart below.

The simple math behind long exposure photography is as follows: every ND-stop will reduce the light with 2. For example, a meter reading without filters for a correctly exposed photograph of 1/400s using a 3-stop filter will result in 1/50s (1 stop = 1/200s, 2 stops = 1/100s, and 3 stops = 1/50s).

TIPS

  • If you want to increase the exposure time, don’t stop down the aperture to anything smaller than f/10. It will lead to an increase in visible sensor dust and due to lens diffraction, the sharpness of the photograph will decrease progressively with smaller lens apertures. Better to add an ND filter. The sweet spot of the lens is usually around f/8.
  • My most used setting is the 5MF8 rule: 5 minutes at f/8. More or less. This means that if your exposure time without an ND filter is around 1/250s, and you use a 16-stop filter, this will result in a long exposure time of 4.5 minutes. If the light circumstances are much brighter and you can’t achieve this target time, then try adding a CP filter which is usually around 1.5 stops extra. Or simply go with anything shorter than 4.5 minutes. In my experience, anything longer than 2 minutes is already a good result. More on 5MF8 here in the original article.

Final word

If you want to know more then I would refer to my original and very detailed article. This article was meant as a quick reference and starting point.

A final highlights article will follow within a month to cover the most important topics on my website in a few short articles. 

Few announcements

  1. At this moment there’s 1 spot left for my fine art architecture workshop in Berlin which I aim to make it a transformative workshop. Long exposure will be a part of the demonstrations. More info here
  2. We just released a 5-hr video tutorial on manually processing B&W fine art images. It’s covering the updated iSGM method now called iSGM 2024 and includes Advanced Masking integrated with Adobe AI. There’s a 20% introduction discount valid up to June 16, 2024. More info here

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