Archive for the 'Tutorial' Category

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HDR Tutorial: What gear do I need?

Stadsaal Cave, Cederberg

 

Right, everybody, it’s on to part 2 of the HDR tutorial, and another example image. This is a view of the Stadsaal Cave in the Cederberg, South Africa. It’s more of a real-world example than part 1 of the tutorial last week, where I shot a random window to show the trickiness of capturing a scene that contains extremes of light and dark. This cave scene is quite tricksy too. What to expose for, light or dark? Easy, expose for everything and let your software sort it out!

The cave’s name translates from Afrikaans to Town Hall Cave. I don’t know if it was ever really used as a meeting hall, but it has historic graffiti all over one of the walls, supposedly by long-gone politicians which tantalizingly hints that maybe it was. Or maybe it’s just graffiti from an age when people cared less about defacing such a beautiful spot. It’s certainly extremely far from the nearest town (or village for matter), so it would take quite dedicated and civic-minded people to meet out here.

 

What gear do I need?

This is a nice and short list, so no need to stress, unless you like to. I’ll be getting into much more detail on all of these items over the next couple of weeks.

Out on your photographic adventures you will need just three things, and most of them are pretty ‘doh!’:

  • Camera – Doh! To make your life easy, you really want to have a digital SLR, capable of shooting bracketed exposures, able to be triggered with a remote control, and with a tripod connector. Set it to RAW mode and the lowest possible ISO. If your camera can’t do any of those things they can all be worked around. I use a Nikon D7000 which does everything I need. Note to self: avoid stirring up a Nikon versus Canon fight.
  • Lens – Almost anything will do, but make sure it’s super clean. The process of combining multiple exposures into one tends to exaggerate any dirt and specks on the lens or lens filters. I suggest a good wide-angle or zoom used on the wider end, but the standard lens that came with your camera ought to be fine. I usually use a Nikkor 18-200mm lens.
  • Tripod – The sturdier the better. Which sadly for your carrying shoulder means heavier. Don’t scrimp of this one. Get something decent like a Manfrotto and you will be able to use it for your entire photographic career. Handholding is possible and I will dedicate a tutorial to that later, but setting up on a tripod will give significantly better results. I know it’s a pain to carry around, but you need to do it.

Having been out photographing and hopefully having captured some awesome images, you are ready to process your first HDR image. What you will need are:

  • Computer – Ideally a fast one with a BIG monitor, but pretty much anything should so. Further note to self: avoid stirring up an even bigger Mac versus PC fight.
  • HDR Software – This software will combine your multiple images into a single image through a process called tonemapping. There are several options here. I use Photomatix Pro, and find it very comfortable to use. You could also use Photoshop’s built in ‘Merge to HDR’ command, or Nik Software HDR Pro which is a plugin to Photoshop. As a free option, there are a couple of options such as Picturenaut or Luminance HDR. I’ve tried several of these, and am sticking with Photomatix for the time being. It just works. If you want to experiment with it, you can download a free trial from HDRSoft that will do everything the paid version does, but will watermark the image.
  • Photoshop – You’re going to need this to clean up your tonemapped image. You will never be able to get the tonemapping exactly as you would like it, so you will need Photoshop to adjust parts of the image, for example by bringing in part of one your original bracketed images to replace a portion of the tonemapped image that doesn’t look good. You could also get by with similar software such as Photoshop Elements or GIMP.
  • Software to help you with noise reduction and sharpening. I use the Nik Photoshop plugins for this, Dfine and Sharpener Pro, and they do a mighty fine job. Photoshop can also manage this without plugins. Photomatix can also help with the noise reduction part.

Next week I’ll be discussing what subjects look good in HDR and what don’t.

 

Before and After

Unlike my epic 11 exposure bracket set from the tutorial last week, where I was really just showing off, here is the bracket set I shot for this scene. This is a far more typical number of shots for me. 5 shots, at -4, -2, 0, +2, and +4. With practice you can probably set up the tripod and shoot the set in less than a minute. I’ll time it sometime and let you know.

 

Stadsaal Cave, Cederberg (5 exp set)

 

Here is the Before and After showing the middle shot and the finished product. The wind was blowing quite hard, which blurred the trees and made the post-processing quite a bit harder. Wind is the enemy of HDR, so avoid it if you can.

 

Stadsaal Cave, Cederberg (before)Stadsaal Cave, Cederberg

HDR Tutorial: What is HDR?

Keurbosfontein Window, Cederberg

 

Today I am kicking off the first of a series on tutorials on how I do HDR photography, in the hopes that I might inspire you to do the same. Earlier this year I saw an image which made me go ‘wow’ many, many times, and it turned out that it was made using the HDR photographic technique. I immediately downloaded some demo Photomatix software and started experimenting. I eventually spent a large part of this year learning about the technique and trying to read and practice as much as possible, and now it’s time for me to pass on that knowledge. It’s also just in time for a new year, and maybe for your new year’s resolution to teach yourself a new aspect of photography? It’s not hard, but it does need quite a bit of patience. Let’s get to it!

This first tutorial is an intro to look at just what is HDR or High Dynamic Range photography? Don’t worry about the acronym or the confusing sounding name. Very simply, it’s a technique that allows you to photograph a scene that has complicated lighting. Where there are extremes of lighting in a scene, a camera, whether film or digital, is not able to cope with the lighting range successfully. Photography is all about capturing the light, and that light is often complicated because that’s the kind that impresses us the most.

A very typical example, which is the subject of this post, is shooting an interior scene with a window onto an exterior view. It’s dark inside and bright outside, and your poor camera does not have a clue how to expose this, which makes it quite sad. You can expose for the scene outside the window, but the interior will be as black as the toast I forgot in the toaster this morning. Or you can expose for the interior, but the outside will be bleached out white like you’ve been staring at the sun too long (instead of watching the toast).

Have a look at the before and after slider below to get an idea of the range of lighting in this scene. The darker image is shot at an exposure compensation of -3 and the lighter one is shot at +3. For those that are new to exposure compensation, 0 represents the setting where the camera thinks the scene is correctly exposed, and any + or – setting allows more or less light into the camera than the ‘correct’ setting.

Keurbosfontein Window, Cederberg (underexposed)Keurbosfontein Window, Cederberg (overexposed)

 

Neither of these images works, but there are a couple of ways you could try and tackle this scene. You could maybe turn on the lights inside the house to illuminate the wall if they were bright enough, but this was cottage in the country with no electricity and candles were not going to cut it. You could illuminate the inside wall with a very big flash or studio lighting, but I don’t own either of those, or have much of a clue how to use them. You could take two exposures, one correct for inside, and one correct for outside, and then combine then manually later in Photoshop, which would probably work quite well. But the most fun way to do it is to take a much larger range of photos to ensure that you have the correct exposure for every part of the scene, and then process them all using specialized HDR software. The software combines the images into one composite image that reflects the correct exposure for each portion of the scene. That’s mostly correct, but also a little bit of a lie, because you can also have a lot of fun with the software and create the composite in a number of ways, from fairly realistic to completely lurid and over the top.

Here is the range of images I took for this scene. Using a tripod to ensure all the images lined up perfectly, I shot an 11 exposure bracket set from -5 all the way through to +5, using 1 f-stop increments. That’s probably overkill, and I would usually have shot a 5 exposure set at -4, -2, 0, +2 and +4 for an interior scene like this, but I felt like going a bit overboard on this one. No real reason. I usually shoot with 2 f-stop increments, and for most images with less extreme lighting I shoot a 3 exposure set at -2, 0 and +2. Shooting a bigger set than you need isn’t much of a problem other than taking more time to shoot and more space on your hard drive afterwards.

Keurbosfontein Window, Cederberg (11 exposure set)

 

These images then all get loaded into your HDR software, you get to tweak a number of sliders and settings, and out pops an HDR image. They usually look a little fuzzy and vaseline-smeared when they are freshly made, and need to be cleaned up quite a bit with post-processing in Photoshop before they are ready to show your friends.

Here’s a comparison using the before and after slider of a fresh Photomatix HDR next to the fully cleaned up and post-processed HDR version of the scene. Over the next several weeks, I’ll be adding several tutorials to go step by step through the whole process, from using a tripod through to Photoshop post-processing.

Keurbosfontein Window, Cederberg (photomatix)Keurbosfontein Window, Cederberg

 

By the way, this picture was taken inside the cottage on the charming homestead of Keurbosfontein, close to where I photographed my previous blog image from. There was no electricity here, no cellphone reception, no people, and it was just terribly relaxing! There were beautiful gardens all around the cottage, even though we were in a very harsh and dry climatic area, and it felt like a little oasis.




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