HDR – High Dynamic Range

So you’ve probably heard me mention HDR and seen some rather strange looking photos where the light just doesn’t look natural and wondered how it’s done?

Well before I explain how, I’ll explain why…

When we look at a scene our eyes and brain work together to process all the light, colours, tints, shadows etc. Our brains are like super computers able to adapt to and identify variations in different areas of a scene.

Imagine a room with a window (you’re most likely in one now), now look towards the window (if it’s day time) you should be able to see what’s outside as well as what’s inside the room. Now get your camera (phone, compact, SLR) and take a photo looking out towards the window. Unless it’s a really dull, dark and gloomy day you’re most likely going to either have one of two photos:

  1. The room is exposed properly, but you can’t really see what’s outside as it’s all blown highlights (i.e. all white)
  2. You can see the view from the window, but everything inside the room looks really dark or black.

Your camera can’t adapt to differences in one scene, it can only expose correctly for one part of the scene for any one photo. Our eyes are constantly adapting for every part of the scene, faster than it takes to think about.

This not a new technique by any means. In the 1850’s Gustave Le Gray, a Frenchman famous for technical innovations in photography, produced some of the first exposure blended photos. He wanted to find a way of correctly exposing for both sky and sea in his seascapes and did so by taking the correctly exposed halves from each negative and combining them to produce one positive photo. The photo below was taken in 1857 and titled ‘The Great Wave”

Gustave Le Gray (French, 1820–1884)

The Great Wave, Sète, 1857, Albumen silver print from glass negative; 33.7 x 41.4 cm (13 1/4 x 16 5/16 in.)

A more recent example of HDR can be found in the photo below. Without HDR I would’ve only be able to expose correctly for either the stain glass window or the details in the hall, not both at the same time.

This HDR effect can be applied to all sorts of similar situations, both indoors and outdoors, such as sunset/sunrise, landscapes where the difference between shadows and light areas is too great for cameras to capture correctly.

Clouds are another good application for HDR; often in photos they can appear slightly flat, and by this I mean that you can always make out the full texture and depth of the cloud from a normal photo. Have a look at my cloud photo one of my earlier posts, you can clearly make out the shadows, highlights which gives a real sense of texture and depth as well as drama. In that particular photo they seem slight more dramatic than usual, and that’s because I had one very extreme highlight, the sun, which I had to expose for the best I could.

Now enough of the boring bit, here how you do it….

Essentially you need a camera that you can alter shutter speeds with, so that’s either an SLR (digital or film) or a bridge camera. Some compacts may have this feature, but only a few.

  1. for digital SLR only: set the camera in aperture priority mode and from the main menu set auto exposure bracketing to the widest settings available. Compose your photo and press the shutter button. You camera will take automatically 3 exposures, one with blown highlights (revealing detail in the shadows), a second that is underexposed (revealing detail in the highlights) and a third photo that does it’s best to correctly expose for light and dark areas (essentially this is used for mid tones).
  2. for digital/film SLR and bridge: as above, put the camera into aperture priority mode and compose your photo. At this point you need to figure out what exposure settings you’ll need and if you’re using a film SLR then you’ll need to work this out from experience. On the other hand with a digital SLR or a bridge you can take some test shots at different shutter speeds to figure out which speeds to use for your three photos. Once you’ve figured this out take the photos and hey presto, put them onto your computer. For film SLR cameras this obviously means getting the films processed and scanned in to you computer.

A quick note before I finish up….

Sensitivity: You should not change the aperture between shots, as doing this will result in the focus being different in all three images (making it a mess). Keep it the same throughout. Another handy tip to bear in mind is to keep the ISO/ASA as low as possible. When exposing for shadows, you’re increasing the noise in photo, the lower the ISO/ASA the lower noise levels.

OK so by now you should know a little bit more about what HDR is, but you only know half of the story when it comes to making a HDR photo…

I’ve talked about how to prepare for a HDR photo by taking multiple exposures, and now comes the slightly more difficult bit. Once you’ve uploaded your photos to your computer you need to merge them to create you actual HDR image, and for that you need some software. There are a number of tools currently available that help you achieve this:

  • Photoshop – this is probably the most popular image editing tool on the market, although it is quite overkill for most people and has a steep learning curve. If you’re simply editing a few photos then it’s not very cost effective (Elements or Lightroom is much better choice).
  • Photomatrix Pro – like photoshop this is probably the most common tool for HDR processing. Unlike Photoshop however, this tool is specifically built to process HDR photography, and you can’t do much else with it.

There are a few other tools out there, but I’ve mentioned these as you’re most likely to be able to find more support and tutorials for these titles online. There’s one problem with HDR photography, initially it was designed to help balance and bring out the details in all areas of the image. However, if you Google the word “HDR” and browse the images you’ll see some quite extreme examples of HDR. It’s quite easy to get carried away with the settings and produce quite garish images. If you have the right photograph though, then a more extreme HDR setting may be quite fitting. It is a personal thing though and there are a lot of purists out there who simply don’t like any kind of HDR treatment.

You can download a free trial version of Photoshop from the Adobe website and Photomatrix from this website:

http://www.hdrsoft.com/examples.html – link also shows what you can achieve with the software as well as user examples.

This page provides a list of resources for guides and tutorials:http://www.hdrsoft.com/resources/index.html

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Humble Beginnings

Do you remember when it started?  Your love of photography that is.

Like most kids I loved being involved in photos, and it originally I supposed it was posing!  However, at point, I can’t remember quite when but I was in primary school, I began developing an interest in actually taking photos.  I remember collecting ring-pulls from a certain brand of fizzy pop and exchanging so many for a free small plastic camera with a small plastic pop up view-finder (basically a square that you pulled up and folded back down).

Anyway, I used to carry this thing around with me everywhere, literally everywhere.  I used to walk to school (yes walk, we all walked back then) and stop every time I saw something interesting and think about whether it was worth spending the photo on.  I say spending, because although the camera was free the film wasn’t, I used to get about 50p a week pocket money so wasting photos on random shots.  Unfortunately I don’t have any of those old photos anymore.

I went a while afterwards borrowing my brothers 35mm compact camera whenever I needed, but then went out and bought a Advance Photos System (APS) camera which gave you the option of taking photos in a number of formats.  I can’t really remember what happened to that camera.

Whilst I was at uni I borrowed my departments 35mm SLR for a couple of projects and this was my first real go at what some would call ‘proper’ photography.  It was still film and I was experimenting, I remember wasting a lot of film, but we got it fairly cheaply from somewhere around campus.

I had a couple of phones with built in cameras which were great, but I got my next proper camera when I got my first job.  It was a bridge camera, basically something a step up from compact but not quite an SLR.  You had access to advance settings like shutter speed, aperture and manual focus, but instead of interchangeable lenses you had a fairly adequate zoom lens.  I used this for a good year or so and felt the niggling urge to get an SLR.

After much research I splashed out £15 on a Chinon SLR with three lenses from an auction site.  I think I gave the Chinon about three months before I realised I couldn’t afford the long term cost of film and processing so I went out and got myself a Canon 350D and a couple of lenses.

About eight years and a few cameras after I’m still as happy and excited when I take photos as I was about 25 years ago, and I hope it will still feel the same in another 25 years.

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PHONAR – Free Photography courses

Hi all, I know it’s been a while since I posted anything, even though I promised myself I’d keep this blog updated…

Lots has happened over the past year or so and I haven’t really been using my camera as much as I’d like to.  Lots of project ideas I’d like to make a start on at some point soon, and loads of posts too.

Anyway, I assume you’re waiting for the bit about this free course…

Well, I noticed that Coventry University are offering a free online photography course for those who are serious about photography and want to learn more.  The class, Photography  and Narrative, forms part of a third year undergraduate course.

From the PHONAR website:

Who should take this class ?
Previous students range from undergrad and postgraduate photography students to hobbyists and practicing professionals. Amongst this year’s registered attendees we have hobbyists, pros, undergrad and post-grad, students, architects, writers, sound engineers, journalists, librarians, musicians, printers and more than one chicken farmer.

The current class is finishing up for December, and I believe there will be another in the new year.

Take a look here for further information and keep an eye out for news about a 2013 start date: http://phonar.covmedia.co.uk/

Hopefully I’ll see you there!

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Lightning

It’s one of those things that as a child I was petrified of.  I remember hiding under tables and generally cowering behind my mum.  I must have been around three then because I distinctly remember being in my parents old house.

At some point later in my life, I must have been around seven then,  I remember walking back home from school with my mum during a thunder-storm.  I listened to the thunder claps and felt that with every clap a little bit of the fear drained away.

Anyway…

Lightning is one of the most beautiful and powerful events in the natural world.  It’s also one of the most difficult to photograph due to unpredictability and speed.  Some interesting facts about lightning:

  • a strike can travel over 10miles from the storm cloud
  • can, on average, carry 10,000Amps and 100 million Volts
  • Crawling lightning (cloud to cloud) has been detected by radar travelling for 75miles distance.
  • it’s hotter than the surface of the Sun.
  • there’s loads more about lightning here

So anyway, unless you live near Lightning Alley in the USA then you’ll just have to be prepared, patient and keep an eye on the weather reports.  Here in the UK we tend to find that thundery storms usually follow a spell of warm weather, even more so if it’s been humid; you’ll notice that lightning has an ionising effect as the air usually feels fresher/cleaner after a storm.

There a few main factors you need to consider when photographing lightning:

  • Day or night?  If it’s daytime photography then you’ll most likely need a neutral density (ND) filter.  For night-time this isn’t so essential unless your environment suffers from a lot of light pollution.
  • Lens: as you can’t predict exactly where the next lightning strike is going to occur, it’s best to use the widest possible angle and you’ll have more a chance of getting it in frame.

Besides the above, it’s more or less playing around with aperture and keeping  ISO/ISA as low as possible.  The method is pretty simple and for it you’ll need a remote shutter release, wired or wireless:

  1. setup the camera on a tripod facing towards the direction of the storm.
  2. set lens to widest angle and attach a ND filter of desired strength (stronger for daytime)
  3. set camera to manual or bulb mode, where the shutter speed is dictated by the length of time shutter button is depressed.
  4. using either manual or auto focus (AF), set the focal point on the clouds – as a rule I generally manually focus to infinity and then dial it back slightly. If AF is used then once focussed, switch to manual to make sure the camera doesn’t try to refocus.
  5. Set aperture fairly high, at least f16, I usually set to around f22 – this is also very dependant on lighting conditions; it’s always best to take a few test shots.Lightning
  6. plug in your remote and depress the shutter button, lock with remote and wait – as soon as you see the strike end the exposure by unlocking the remote shutter release.
  7. the exposure time will vary considerably depending on your lighting condition, aperture, ND filter strength etc.

So there is it, a little fiddling, patients and luck should leave you with a nice photo; if it has lightning in it, that’s even better! 😛

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Sharpness & Depth of Field

Sharpness and depth of field (DoF) are two very common elements of photography that help achieve very different outcomes.

Sharpness is pretty much what it says on the tin, it’s how in focus the image is.  The majority of SLR lenses tend to be sharper if they are stopped down to around f8 to f11, few are sharp wide open.  However, stopping down much further than f11 isn’t really going to improve image sharpness much, and in some cases can even begin to degrade image quality.  When talking about sharpness in this instance you’re talking about sharpness at a particular point on the image or put another way, the sharpness at a particular distance in the scene.

Another effect of stopping down/using a narrower aperture is that more of the image comes into focus, this is what is referred to as depth of field.  Depth of field can be used to great effect in photography and even in cinematography.  There may be times when you want to isolate the subject from distracting background/foreground and this can be achieved by using either a wider aperture or placing some distance between the subject and background/foreground such as in this photo:

Sweet spot

Focus is sharp on the drop of honey only

Landscapes and architectural photography generally require high DoF, so the priority here is not to concentrate on one point in the scene but to get as much in focus from front to back.  The only way this can be achieved is with a narrow aperture, which is why many wide-angle landscape lenses can stop all the way down to f22 and some even further to f36.  There is a trade-off here between optimal sharpness at one point in the image and overall focus, and some lenses handle narrow apertures much better than others.

In summary, there are instances where more DoF is required and a small sacrifice has to be made in order to to achieve that, and the amount of sacrifice will be dictated by the lens.

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You’ve Got Mail!

It’s been a long tiring day at work, you get home only to find that you can barely push the door open.  You manage to open it wide enough to squeeze inside and you see the problem…

….a pile of flyers that have built up over the day.

It doesn’t end here though.  Once you’re in and have settled into whatever it is that you’re doing, you can hear the constant clapping of the letterbox flap, this carries on late into the evening. So now you’ve got a tree’s worth of flyers that are just going to go straight into the recycling bin.  It’s such a waste.

What can anyone do about this?  I suppose it doesn’t help that I live five minutes’ walk from the University (hot spots for take-aways).  I can’t go around all the local business and ask them to take me off their mailing list;  even if I put a sign up it’ll get ignored.  I’m not angry at the distributors, because lets face it, at least they’re working!

So the other day I decided to turn the situation on its head and have a bit of fun with it.  I was minding my own business clearing up the living room when I noticed a distributor approaching the house.  I hid beside the door and as the he open the letter box to put the flyer through I shoved my hand through frantically grabbing the flyer off him.  To say he jump back would be a bit of an understatement.

I did open the door and apologise to him after, he was quite shaken but managed to smile and walk on to the next house.

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Mocha and Lemon Cakes

Right, so I’ve made some cakes and taken them into work and everyone is asking for the recipe. So as I was making a cake tonight anyway I thought I’d go ahead and take photos while I cooked!

The cakes I took into work were coffee and walnut with a mocha buttercream filling and a lemon cake with a lemon buttercream filling. Tonight I made a mocha sponge which I’ll be filling with tomorrow night with cream, strawberry and kiwi fruit slices (fresh). The recipe and method for all cakes is basically the same but I’ll talk about the coffee and walnut and lemon cakes too.
Just as a note I used 8″ (20cm) circular cake tin 2″ (5cm) in depth.
Ingredients:

Mocha sponge

  • 350g self-raising flour
  • 350g margarine
  • 350g castor sugar
  • 7 large eggs or 8-9small eggs (roughly 1 egg for each 50g of flour, duck eggs are meant to be much nicer in cakes, but I’m not sure about size and quantity)
  • 1 teaspoon of baking power
  • 3-5 heaped teaspoons of cocoa powder
  • 2 heaped teaspoons instant coffee
  • 2-3 teaspoons of coffee flavouring

Lemon sponge

  • as above but with out cocoa powder
  • 3 unwaxed (waxed but washed) lemons for the rind and juice
  • 2 teaspoons of lemon ‘extract’ not essence

Coffee & walnut sponge

  • as mocha but without cocoa power
  • 3-5 heaped teaspoons of instant coffee
  • a large handful of shelled walnuts
  • Coffee essence

Cream filling

  • 1 tub of double cream
  • castor sugar (optional)
  • vanilla extract (optional)

Buttercream filling

  • 75g of unsalted butter
  • 175g icing sugar
  • lemon extract / coffee essence

Equipment

  • large mixing bowl
  • 2 small bowls
  • wooden spoon or electric food mixer/whisker
  • palette knife
  • sieve (medium to large)
  • cake tins 8″

Method:

Note: before doing anything below, preheat your oven to gas mark 4, and grease the cake tins. I find it better to use grease proof paper as well to line the tins.

  1. Separate the egg white from egg yolks into two bowls.
  2. put the egg white into a mixing bowl
  3. add the castor sugar
  4. beat the egg whites and sugar until you get a thick white mix, like mouse in consistency (this is where a food mixer comes in handy)
  5. now add the yolks and mix
  6. followed by the margarine, better to dice this up first, easier to mix.
  7. now sift in the flower (even if it says ‘no need to sift’)
  8. add a teaspoon of baking powder (fairly heaped)
  9. If you’re using a food mixer it’s better to stir in the flower else it’ll blow everywhere
  10. At this point you should have a fairly light consistency of sponge mix.
  11. now is the time to add your preferred ingredient, coffee,
  12. walnuts, cocoa, lemon etc…
  13. Walnuts could do with a bit of crushing so wrap them in cling film or foil and smash them up with either hammer, rolling-pin or anything else that works! :o)
  14. Any rind or flavouring can go in now as well
  15. After adding any additional ingredients such as the
  16. above, give it another good mix.
  17. spoon the mixture in to your two cake tins and slam them into the oven for about 30mins at gas mark 4. This cooking time will vary from oven to oven. Fan assisted ovens will cook quicker. However, you need to be careful not to have the temperature too high as the cakes will balloon and burn, leaving the inside soggy and wet! The best way to make sure your cake turns out nice, even and unburnt is to cook it nice and slow.

Buttercream

  1. this can be a pain to get right and take a while too, especially if done by hand so better to leave the unsalted butter out of the fridge at least an hour or two before you make it.
  2. dice up the butter and beat it in a mixing bowl to soften it up (takes a while by hand).
  3. once the butter has softened start sifting in the icing sugar gradually mixing it all in.
  4. add a little warm milk to help soften even more and add a little fluffiness to the texture. It’s important to add the milk 4-6 drops at a time, too much and you’ll need to top up again with icing sugar.

Standard cream: this is fairly simple, just whisk it at high-speed and add any flavouring you wish. Sugar is optional if you like it sweet!

Happy Baking!!!

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