It is trendy – and more important it is necessary – to
reduce our carbon footprint. Let’s calculate how much a bad habit of
photographers can pollute.
I am taking in average 10 to 20 thousand images per year.
Many pro photographers will shoot ten times more, typically above 100 thousand
images per year, if not more. At the same time, for different reasons, it
happens I am working hard at keeping only the best shots. Typically, from these
10-20 thousand photos per year, I am storing only 1 or 2 thousand per year. And
there is even room for improvement. I don’t think this ratio is exceptional.
Other people report a typical ratio of 80-95% of useless images, whatever the
reasons. However, I must confess this eradication takes me a lot of time and I
do understand why people don’t do it – it should be somewhat automated. I was
wondering what the impact of keeping all these useless images is. How many greenhouses
gas does it generate per year ? Basically, I am wondering how much our useless
images can pollute when we don’t eradicate them.
How many tons of carbon dioxide per thousand of images stored?
Simple question, difficult answer. First and foremost, there
are head and tail winds: Whereas 1 Gigabytes (GB) of data require less and less
CO tons every year, images are becoming bigger and bigger as new sensors let
you shoot with more megapixels. Same situation for videos. It looks quite
challenging to anticipate the future trends but let’s make the calculation as
per today, in 2019. It is reasonable to believe head and tailwinds will not
completely change the result in the next years.
Let’s try to calculate just a rough estimate…
In this article, I don’t make any calculation for videos,
just for the still images. I will consider 3 categories of photographers:
casual photographer who typically take 5
thousand images per year,
enthusiast (20 thousand images per year)
and pro photographer (100 thousand images per
Casual photographers only create JPG files from their photos in this exercise, with a 24 Mega pixels camera. So, each JPG file weights typically 5 Mega Bytes (MB) each. This means 5 x 5’000 = 25 GB per year.
Enthusiasts shoot RAW, with 36 Mega pixels camera. They convert 10% in JPG, of 7.5 MB each. This means 36 . 20’000 + 7.5 . 2000 = 735 GB per year
Pros will shoot both RAW and JPG, with different cameras and
sensor. Let’s make a rough estimate at 15 MB per image. This means basically 1.5
TB per year.
To summarize, I will just consider 1 TB per year per photographer.
This will simplify the calculation. It will not change the whole result and it
will be consistent with the kind of photographer we are looking at for this effect
(mostly enthusiasts or pros).
All these numbers are arguable but that’s a good starting
point for a first estimation.
Now the key question is how much carbon dioxide emissions for 1 TB ?
Several studies have proven that we need around 100 kg of
Carbon dioxide emissions to store 1 TB of
data on the cloud (ref. ,  and . Again, the calculation is quite complicated,
and the range is very broad, from typically 50 kg to 2 tons. I am considering 100
kg as a conservative estimation.
This means 1 ton per year for 10 TB, after 10 years of
photography as it is cumulative.
What does it mean in a sustainable world?
In a sustainable world, the average individual rate should
be of 3 tons of carbon dioxide per year (ref. ). We are far from that level now
(US: 18-20 tons per year per person, China: 6.5 tons, …) but that’s where we
It is useless to say we can’t use almost 1/3rd of our yearly quota (in a sustainable planet) just for storing images. It should not be more than a couple of percents. Once again, it proves that a sustainable world will have dramatic consequences to our life. It means we should eradicate all our useless images as they represent 80-95% of this storage emission.
It is time to reduce our data from images and videos. Besides storing too much and mostly useless information, it is necessary for living in a sustainable planet. Of course, one can object these data “might” be useful in the future, who knows ? At the same time, it is good practice to focus at what really matters and be able to retrieve this important information later when needed. Less is sometimes better. And we always find good excuses to refuse change. But this change is needed and in the long run, inevitable. It is time to be consistent and eradicate as a “pre-post processing step” most of the useless images, whatever useless may mean.
in photography is well known and whereas sometimes done on purpose, it mostly
comes as a non-desirable effect, because of poor exposure (worst case) or at
least reaching the limits of the sensor range (best case). By clipping, I mean both
blowing highlights and clipping blacks. The topic has been debated countless
times in different forums and blogs.
As a summary, some people believe it does not really matter
as long as the photo is great and other advocate why and how to avoid it. Other
rightfully point out it is sometimes better not to fix it whereas other explain
in detail how to do it the right way.
This is a classic case of different opinions in photography
between those who do not want to consider something else than the purely
artistic result and the scientists obsessed by being consistent with some
physical principles. As usual too, both are right and wrong at the same time.
Indeed, what matters in photography is the result, the emotions a photography
can carry, and whether you like it. Period. Clipping, no clipping, who cares.
At the same time, it is true to say that blowing your sensor which can no
longer deliver any information but “I am blown” (white burned) or “I am blind”
(black clipped) is not really what someone can call good practise, to say the
I am trying in this post to find a way to make all these
opinions somewhat aligned, in a very much Swiss-like consensus way.
How to detect it and how to fix it
There are also plenty of information about the topic. I
would recommend reading:
Most of the people know well the “physical” clipping: when the sensor is blown. Technically speaking, it means the pixels of a given channel (R, G, B) or its luminance (Based on the square root of R, G, B weighted according to the human eye characteristics) is at its maximum value (typically 255 for 8 bits JPG) or its minimum (0).
But it is also important to remember that what matters is
the “visual” clipping: the pixels that are almost blown or clipped also matter
because (at least for JPG images), there can be no way to really fix them
properly and get information from the clipped regions of an image.
Let’s have a look at the clipped pixels highlighted in blue for the blacks and red for the highlights in the image below. First, one could argue that using JPG for such conditions is not the best idea, RAW would have been by far a better choice but without going to start another countless debate RAW vs. JPG, the image has been poorly exposed as there is no clipped pixels in black (they would be in coloured in blue in the image below) whereas they are quite a few blown ones (in red below). So, basically, it says the image should have been significantly less exposed..
But whereas the number of actuals blown pixels in red is not
so significant, the number of visually clipped pixels is at an unacceptable
level. It is making the image ugly whereas it was an interesting one. There are
almost blown from a physical perspective, but for our eye, they are just blown…
you can try to reduce highlights or exposure, there is basically no information
recorded into the sunny mountains part of the photo. The image will stay poor.
So, what matters is not the truly clipped pixels but those which look clipped. Using
Lightroom or other software tool is not enough even if, again, you can’t do
much to fix it when you shoot JPG. That’s a good transition to the next point.
Clipping is not the same animal when you shoot RAW or JPG
I believe it does make sense to differentiate JPG from RAW
images when it comes to clipping. For RAW images, with modern sensors, clipping
images is rare. Or you really do it on purpose. Or you have no idea how to use
your camera’s exposure systems! The below example shows how tolerant sensors
are now to clipping:
I know it is not so simple and you can clip some parts of a photo
despite your goodwill and expertise whilst shooting RAW. My point, however, is
to say it is rarely a problem and it is easy to identify and to anticipate as
it will only concern extremely high contrasted images.
When it comes to JPG, this is a totally different story. It can
be easy to clip parts of an image and it can be difficult to fix it as we have
seen above. What matters is first to know quite well how to detect that the
image will have some clipping. Second, you need to know whether it is a problem
for your image or it is not. There is no good answer to this (from my
perspective, though, it will very often be a problem). One approach would be of
course to shoot RAW anytime there is a risk of clipping, just to have more
latitude in the process, but it is not always possible or desirable. At least
you know what to do. So, it looks important to understand the causes and the
consequences of clipping and how RAW can fix it while bringing the usual inconvenient
of shooting RAW (processing time, file size, buffer limits, …). If you don’t
shoot RAW, you normally have reasons for this choice. This is a good transition
to the next point: this is where good and bad clipping matters as well in your
The Good clipping and the bad clipping
The bad clipping is the one you should not get. Just expose
better your image by underexposing it when you have bright parts or
underexposing it when you have potentially too many black clipped pixels.
The good clipping is just inevitable. Below an example:
When we analyse the image below, we can see we have both blacks
clipped and highlights burnt. In red the burned pixels, in pink the “visually”
clipped ones. In dark green the black clipped ones and in light green the “visually”
Having significant both red and green zone just say you are
going beyond the capabilities of your sensor. Just buy a better one with a
higher dynamic range… or use an artificial way (flash, umbrella, filters …) to
decrease the contrast, which of course is not always possible or desirable
depending on the kind of pictures you are shooting.
Conversely, if you aim at having high (or low) keys images, the
result will be clipped, fair enough but the pre-processed images – before you
start to work at them, the RAW images or the JPG out of the camera should not
be clipped. And to illustrate this, a cute gallery that I like of high
I like these images but I would not bet they were clipped out
of the camera.
Good principle: clipping is bad
Long story short, it will be difficult to convince me
clipping is not bad. Indeed, if you are looking to shoot high or low keys image
or if you want to stylize your images, that’s more a post process thing. If you
know what to do, you can argue “I clip on purpose” but most of the time,
clipping is just bad. Your sensor doesn’t provide information any longer but a
very black and white approach of the reality. What you will do in the post
process is a different discussion, when you shoot, and you anticipate clipping,
unless knowing exactly why, you should just take whatever it takes to limit it
(thanks to under/over exposing or bracketing) or avoid it (same actions + RAW +
Conclusion and summary
Let’s start by another example. From my perspective, this
image below is poorly exposed, over clipped in a white grey ugly sky:
The light was terrible, due to some haze caused by hot air.
This image looks ugly to me whereas Mopti is such a dramatic city and I have
tried to post process it, there was no way to fix it (I was travelling, was
short on time, and I did not see a way to avoid clipping). Light is bad, it is
what it is.
My point: clipping is (very often) bad even if you can’t
avoid it. They may be some counter examples (try to shoot an image of a polar
bear in the artic without clipping the snow…) but they demand to have at least understood
how to produce a pleasant image and taking counter measure to reduce the visual
impact (shooting RAW, shot only when there are some shadows to produce some
darker zones, …).
When you always shoot the same kind of picture, you know what
you are doing. You don’t really need the following conclusion as you have no
problem to deliver images you are familiar with. But it is also good in life to
try new things. And it is good to remember some good principles because when
you shoot new subjects, in a new way, in new places, you will have many reasons
to fail delivering great images. It is good to remember some basic principles.
Beyond all the discussions and remarks, I like to remember something easy not
Shoot whatever you like, but clipping is bad.
The more you know how to detect it, avoid it or at least manage it, the better. It is not a fight between art and science, it is about discipline.
A few years ago, the main reason to buy and use DSLR where mainly the following:
Better images quality Optical view finder Great control of the depth of field (thanks to bigger sensor and faster lenses) Better controls and ergonomics Faster AF and many images per second Access to a full photographic system of lenses, flashes and other accessories
Nowadays, thanks to enhanced sensors, mirrorless cameras, miniaturization, specialized cameras for every kind of photographers, most of these reasons have become less and less true. Of course it still makes sense for some professional photographers, of course I and many amateurs still prefer shooting with a DSLR but as a matter of fact, I like to say the main reason to still go for such a camera is: “I don’t want to compromise”. “I accept to pay a lot, to carry a heavy bunch of gear, to have several bodies and many lenses and accessories, because I will also accept to spend hours on post processes of my images. All I want is the best gear available to let me have the pictures like I want to”.
This means an APS-C sized sensor (DX for Nikon) DSLR does not make sense any longer but for those who never tried beforeap one (like a Nikon D3200 which costs less, by far, than a mirrorless whereas able to make really excellent images). Frankly – I own a Nikon D7000, I don’t see the point having nowadays a DX DSLR when you are an “experienced” photographer. Full frame (FX for Nikon) cameras are becoming really affordable and are somewhere, the only consistent option for a DSLR given the present competition of great mirrorless cameras and excellent compact cameras. Back to before 2000, at this time, only such cameras existed!
It does not mean the manufacturers will stop developing lenses for DX, nor will stop releasing new cameras (Nikon refreshed its D7000 recently by the D7100), I just don’t recommend investing into a DX DSLR system. If you have one – like me – you can still use it a secondary system, or because it still works very well but the DX time, basically, sounds to be over to me. Buy FX DSLR cameras if you want no compromise, and middle format should you be able to afford it. Again, if you are on budget, a DX DSLR could be your first DSLR, but it will just be “temporary”. And don’t forget mirrorless, compacts and smartphone as complementary but “mandatory” cameras.
Nowadays, it does not really make sense to own just one camera. And certainly not a DX DSLR!