Few things in life draw as much universal admiration as a rainbow streaking across the sky with its vibrant colour spectrum, I don't know a single person who doesn't love a rainbow.
Rainbow over Chesil Beach, Dorset.
Why Photograph Rainbows ?
They are prized amongst landscape photographers and non photographers alike, its one of the few things that evokes a universal emotion from all people, instant joy and happiness and gasps of awe.
I have seen numerous times in the past people who are not photographers come to screeching halt whilst driving to jump out of their car and capture a rainbow on their phone.
I don't know of another single subject that has quite the same effect on the general public, sunsets can be ignored but never a rainbow, everyone wants to capture that special moment and rightly so.
Perhaps the fascination of a rainbow is the fact you never really know when or where one will appear ?
And when they do they can be fast and fleeting, here for a few seconds and gone the next. On rare occasions they will be there for longer periods of time and I have personally witnessed rainbows lasting as long as 30 minutes before, but these are few and far between.
Perhaps the only guaranteed time one will come out is when I'm at work stuck in the office without a camera and have to stare through the windows with that slowly sinking feeling on missing out on something really special, unfortunately this happens way too often.
Rainbow over Portland, Dorset.
So this illusive sky spectre is indeed prized most highly by landscape photographers and it happens to be one of my favourite things to shoot and I've learned a lot about them during my years of chasing which will hopefully help you to capture a few of your own, alas I can't help with the pot of gold at the end of it though, That, in my opinion is the capture itself of these wonderful visions.
The Thrill Of Chasing Rainbows
The thrill of the chase is also a factor with this type of photography, Nothing gets the adrenalin flowing more while chasing around after one and the feeling of expectation that something might just be about to happen, Simply wonderful !
Some of the mystery of a rainbow is the fact that you are rarely seeing all of the masterpiece, only half the arc due to the way the light is refracted but those who have been lucky enough to witness a rainbow from a aeroplane for example can be treated to the full circle on rare occasions revealing the unrivalled beauty of these teasing mistresses of the sky.
I chased this shot for four years before I finally got what I was after, Horton Tower, Dorset.
So what can we do to improve our chances of capturing these illusive wonders ? Understanding them is the first step, how are they formed, what conditions are needed, what in fact are they ?
Education about rainbows starts at an early age, I still remember learning some 35 years ago at school the rhyme Richard Of York Gave Battle In Vain which was the easy way to remember the order of the colours of the rainbow.
Richard RED
Of ORANGE
York YELLOW
Gave GREEN
Battle BLUE
In INDIGO
Vain VIOLET
It struck a chord with me then and I still remember it to this day such was the excitement and intrigue of a rainbow.
The colour scheme order of a rainbow never ever changes on the primary body of it, however if you are lucky enough to witness a secondary or "double rainbow" then the order of the secondary rainbow is reversed to VIBGYOR, This often catches out photoshopped examples where people simply haven't noticed it before assuming it is the same all the way through.
An example of how shooting with a longer lens can give you a different impact on the shot
What exactly is a rainbow ?
It's simply refraction and reflection of light.
When light passes through suspended water droplets they act like a tiny prism which disperses the light and indeed reflects it back to the eye. The circular shape of a droplet causes the light to be dispersed at angles and splits it down to the colour spectrum which you see in the sky.
So do you need rain in order to see a rainbow ? Surprisingly no, its about water droplets in the air but not rain itself, although this is the most common way to see a rainbow. For example it is very common to see a rainbow at a waterfall as the vapour or spray from the waterfall refracts the light, mist as well can cause the formation of a rainbow or indeed the super rare "Fog bow" which we will cover later.
You might have been watering your garden or washing the car with a hose pipe and seen a mini rainbow forming as the you catch just the right angle and the light pours through the water spray. The important thing to remember here is water in the atmosphere rather than JUST rain itself.
Another example of this is when you have been standing somewhere dry and there has been a rainbow formed but no rain to be seen close by, its guaranteed it is in the air somewhere between the path of light and the rainbow formation itself, again wonderfully unpredictable and part of the joy of seeing one.
Osmington Mills Waterfall rainbow, Dorset.
What Conditions Do You Need For Rainbows ?
Do you need sun for a rainbow ? Well, for the most part yes but also no. The rainbow is formed by light and it is possible to have a rainbow at night with light from the moon forming a "Moonbow" which has the appearance of being white but are in fact, still made up of various colours but the moon light is far weaker which is why they appear white, These are super rare and I've never actually seen one in the flesh but have seen pictures of these wonderful apparitions.
So back to the original point. No, sun light is not needed for the formation of a rainbow but LIGHT itself is, but for the purposes of photographing a rainbow then sunlight is the best chance of getting one for obvious reasons.
Sweeping light & stormy skies as west Dorset delivers a rainbow.
Best Time Of Day For A Rainbow ?
So, can you see a rainbow at any time of the day ? Again surprisingly no, well no of sorts. Rainbows are most common in the morning or late afternoon simply due to the position of the sun in the sky. The optimum position would be 42 degrees. This is where it gets confusing as in the height of summer as the sun is at a higher point at mid day for example then you won't see one, but in winter when the sun at mid day is in a much lower position then it is easily possible to get one. The angle of the light is the deciding factor and as you look at the sun position throughout the year you can see it get progressively lower on the same cycle as days get shorter and vice versa for the summer months.
The position of the sun will also have a bearing on how bright your rainbow is, for example if the sun is very low in the sky almost at setting point it is possible to get a "red rainbow" which is essentially because the lower the sun is the lower the angle and intensity of blues and greens in the light as they are the inner part of the spectrum thus giving the appearance of a red rainbow. I have witnessed this only once and sadly didn't get to capture it due to the position of it behind houses with just the tip of it showing but they really are quite spectacular to see.
Rainbow over Poole Harbour, Dorset.
So we now know when is the best time for a rainbow so let's look at conditions, the three main elements, light, water and position of the sun. The optimum conditions for a rainbow as I'm sure you have all experienced is right after heavy rain and with intense light streaming through onto the rain or vapour.
Now it seems a pretty obvious statement but a rainbow will always be opposite the sun so be sure you're facing the right direction and moving in accordance to the pattern of the sun. I say this is obvious but believe me people don't always realise this and are often looking in the wrong direction, no seriously !.
The type of rainbow you get will effect the choice of how you shoot it, do you have a full arc ? do you have just a small section of the rainbow ? Will you be using a wide angle lens to photograph it or a telephoto zoom with a longer focal length, all need careful consideration in order to get the best out of it.
I will try and run through the scenarios and how I approach shooting each type.
The Full Arc
By far the most prized of all the rainbows but probably the hardest to capture well.
Obviously in order to capture the full arc you will need to shoot fairly wide such as 16-17 mm and even then you might not get it all in.
For these shots I make sure I am NOT using a polariser filter as with a slight rotation too far you will make the rainbow vanish from your picture due to the way the polariser works. You may have seen pictures in the past where a full arc rainbow seems to be missing a bit of it, chances are these were taken while using a polariser which had been rotated too far, although mother nature herself will dictate the form of the rainbow and if its the full arc or not.
If your wide angle lens is not wide enough to shoot the full rainbow you can simply switch it to portrait position and do a panorama to get the full rainbow, again another reason NOT to be using a polariser filter in this situation as it will make blending a lot harder as the colour of the polarised areas won't match up in most cases.
The Half Rainbow
Now this is the complete opposite of the above, when you have a rainbow streaking up into the sky but you can't see the end of it, these can be super dramatic and are far easier to capture in my opinion.
This is where the previous advice gets flipped on its head and you absolutely SHOULD use a polariser filter, it will give the rainbow absolutely amazing punch and intensify it, I can't recommend this highly enough.
You can of course shoot one without it but once you have used one for this type of rainbow then you simply won't go back, the results are nothing short of spectacular.
Long focal lengths are great for these enabling you to get close in and with a good foreground subject to give depth, balance and strength to the image.
Rainbow over Bat Head, Dorset. (Long Lens)
Which Lens Is Best For Rainbows ?
Whilst wide angle lenses will also work for the shot they are in my opinion for less effective as the rainbow is less prominent and there can be too much empty space in the shot and it loses impact.
With this situation it is not uncommon for me to take two cameras with two different set ups, one with a long lens (70-200 mm or 100-400mm) and then another with a wide angle lens (16-35 mm or 24-105 mm) so I am equipped for any situation as swopping lenses in the middle of heavy rain is a recipe for disaster and absolutely not recommended.
I appreciate this situation is not something that most people will be able to do as usually people own one camera but if you do have the luxury of owning two it is a tactic well worth employing when chasing rainbows as I guarantee it will score you extra shots at some point as well as having two very different views of the same rainbow, a bonus!
This shot and the one above are perfect examples of a wide angle and a long lens shot of the same rainbow but both producing very different results, Filling the frame with the long lens gave the better picture in my opinion (Bat Head)
How To Expose A Rainbow Correctly
In terms of exposure then I will always try and shoot a rainbow in full manual mode, the reason for this is that it will inevitably be in very bright light but also heavy shadowing and the cameras meter is often fooled by the light and manual mode will give you complete control over this and enable you to expose for the scene in front of you.
Manual focus is also employed here and not for the rainbow, focus for the scene, not the rainbow.
You should approach it in roughly the same way as if you were shooting the scene without a rainbow, looking to focus roughly a third into the frame for the wide angle shots whereas you should focus on the "Feature" if shooting with longer focal lengths in order to make sure your isolated subject is pin sharp and the rainbow will take care of itself.
Bournemouth Beach Rainbow.
There are no hard and fast rules about settings for a rainbow as the scene will totally dictate what you use, a good base start is with the wide angle at F11, ISO 100 and shutter speed to suit, Long lens F8, Iso 100 and again shutter speed to suit.
For scenes where you are including heavy foreground and lots more layers then extending up to F16 is a better bet.
One of the best ways to ensure good results is to bracket your shots, that way you cover all bases, that's assuming the rainbow has lasted long enough for you to do this.
Having the clipping alerts on in your camera will also make you very aware if you have over done the shot with the dreaded "Blinkys" flashing up for over exposed areas, but as stated the histogram is your friend here with accurate brightness representation.
I try and keep my ISO as low as possible, usually ISO 50 but if wind is a factor and foliage is moving then I will move to a higher ISO in order to give me the desired shutter speed to freeze any motion.
The reason for using the lowest ISO is that I want the best possible quality for post processing as rainbows can be notoriously difficult and from past experience the less processing the better on them.
Rainbow over Creech Hill, Dorset.
How To Post Process Rainbow Pictures
When you have a rainbow that has millions of colours due to the graduation even though we only name 7 of them ROYGBIV, there will be by nature be a perfect transition through each of the colours, once you start adjusting levels and curves in post it can throw out these transitions and adjustments become really noticeable. Light adjustment at most is all that is needed, the rainbow is a thing of beauty and needs very little adjustment for that to show through, anything more will butcher it.
The weather forecast always fills me with excitement and joy when I see sun and rain for the day, I know I will be out chasing rainbows and loving every second of it.
It gives you a chance to pick out your locations in advance and anticipate where a rainbow will form at the relevant times of the day.
Now this is not an exact science and I can't tell you how many times I have stood in the rain for hours waiting for one only for nothing to happen except for me to get thoroughly soaked. However, I still think its totally worth every second of it for the chance of a rainbow in a great location.
Those that know me know that I have been chasing rainbows at a specific location for upwards of 5 years and still not managed to capture a full arc, I've had the small strips of rainbows there but never the full arc and its been an ongoing challenge ever since and has been my go to place for a long time, I will eventually get it even if it kills me ! Never give up !
St Catherines Chapel Rainbow, Dorset.
The Little Edge !
While on this subject its worth mentioning a little edge I have which will sound daft but being a dog owner every pocket of every item of clothing always seems to have empty dog poo bags in and these are perfect for slipping over the camera and lens while its on the tripod complete with filter set up ready to shoot.
There have been so many times while I have watched others waiting for the rain to stop so they can unpack their gear and get the shot only to miss it completely as the rainbow has come and gone in the time its taken them to set up, meanwhile I have simply pulled off the poo bag and nailed it in seconds, you might think it sounds daft but believe me it has scored me so many extra shots in the past.
For those of you without dogs (why would you not have one ?!) simply store a carrier bag in your back pack and pre focus your camera and settings then "bag up" ready.
I prefer this approach to an umbrella simply because if its windy you can't hold on to it and umbrellas have a nasty habit of dripping water in the most awkward of places when you turn round to get something from your bag only to get drips all over your lens, trust me here poo bag for the win !
Alexanders Dark Band
Another phenomenon you may notice when you get back to your computer and look at your pictures on the bigger screen is a darker area between the primary rainbow and the secondary rainbow, this is called Alexanders dark band and was named after Alexander of Aphrodisias who first talked about it in 200 AD. Now the full explanation of this is quite complex so I will try and summarise in layman terms to make it easier. When light is reflected through a droplet it can sometimes cause a secondary reflection which will be seen as a secondary rainbow. This secondary rainbow is a further reflection hence one is brighter than the other and the sky between has less light reflected on it therefore appearing darker, still with me ?
If you want to know more about this look up "Minimum deviation angle" which will explain it in much more scientific way and in far greater depth. In short you don't need to "correct" this in post processing, its not a camera fault or a bad shot its a naturally occurring phenomenon and should be there.
Rape seed field Rainbow, Dorset.
I tend to rely heavily on the histogram for rainbow shots due to the excessive brightness that is part and parcel of shooting them, its very easy to over expose and indeed under expose if using the cameras metering judgement so I suggest you keep a close eye on it (as you always should for any shot).
Like with any winning shot the composition is the key and therefore planning is even more important. I have so many early shots of rainbows that were simply formed while I was out and I just jumped out to shoot the rainbow itself paying little or no attention to the surrounding landscape and the composition and while at the time I thought these looked great showing the beautiful rainbow, they were simply snaps, not good images.
I started to plan my rainbow shoots with far more precision and anticipating where and when a rainbow would form so I could tie it in with compositions that worked along side it and these have been much better shots.
Expect The Unexpected
Now I know there will still be times when an unexpected rainbow comes out and the mad rush to capture it begins but I urge you to slow down, think about the scene in front of you and try to get a winning composition before the rainbow, don't be blinded by the rainbow itself. It might well be the centrepiece of the image but it is still just an element of the whole picture, a mere section of great dialogue in a movie, its not the whole film, treat it that way and think about the bigger picture and you will finish up with something wonderful.
When rainbows are out chances are there will be angry cloudy skies and beautifully lit areas of foreground for you to make the most of and compliment your rainbow picture.
Another area well worth looking at is lakes when a rainbows due, the reflections you can get can make the scene even more interesting and can turn a double rainbow into four !
Rainbow Reflections, Wiltshire.
Im no expert in chasing rainbows and these ramblings are simply just what works for me and hopefully some of you will want to give it a try and share in the euphoria I feel when I get lucky enough to capturing these fabulous, vibrant phenomenons.
If you take the above advice and also if lady luck is smiling down on you then I guarantee you will nail some shots the next time you see a rainbow.
Finally its worth mentioning some of my very favourite shots have come while chasing rainbows but not actually getting one, the rainbow is the crowning moment should it come along, but fantastic light and heavy clouds will often give you a stand alone stunning shot even if the rainbows are not playing ball.
Corfe Castle, Waiting for a rainbow that never came.
Above everything enjoy your time chasing these colourful sky serpents and don't forget your waterproofs ! ;)
Happy shooting
Daniel Wretham
*Please note all of these pictures on the blog are extremely low resolution so don't reflect the image especially well.
Rainbow and light, dream conditions
