How to HDR


HDR photography using qtpfsgui

I am writing this guide because many friends have asked me how I create my HDR photos & now i am going to share a very simple & easy method to achieve such results using a free piece of software called qtpfsgui, which is available for pc, mac or linux. In this example i’ll be using the Mac version, but all of them are pretty much identical.

What is HDR?

HDR photography is created by composing three images of a scene that have been captured in different exposures by using Auto Exposure Balancing (AEB). Most current dSLR’s will have these an option in their menu for auto exposure bracketing (AEB) & when this is set your camera will take 3 different exposures of the scene. It basically works like so;

1 under exposure – captures more detail in the highlights
2 normal exposure – captures high/low’s equally
3 over exposure – captures more detail in the shadows

Because you are doing this you are essentially capturing a whole lot more information with regards to the shadows & highlights of the scene. If you think of a single JPG image as being 8 bit, then by having 3 images you basically create a 32 bit image to work with. When you start doing this you’ll discover a that you are able to bring a whole stack of extra texture & mood in your shots which would previously be unable to have been seen in a single exposure alone. If you want to know more about HDR in a little more detail, visit Here.

In order to create these images you’ll require the following;

  • a digital camera capable of Auto Exposure Bracketing (AEB) & also capable of saving in RAW format.
  • a stable tripod
  • Software to view previews of your RAW format images
  • download a copy of Qtpfsgui, it is available in mac,p.c. & linux flavors. You’ll need to follow their guide to install as I had to also install an extra Quicktime pack in order to get the software to work.
  • some time to experiment, as not every scene will render as a good HDR.

Ok, Let’s get started…

1) Find a suitable scene.

I recommend something with lots of texture, depth of field & little movement. Always use your lowest ISO as grain will show more in HDR renderings. Setup AEB on your camera & take your shot on a tripod. It is really important that the images be very still so avoid all camera shake or this will result in ghosting. If there are moving people & or vehicles in the shot you will get some strange ghosting effects, which can sometimes work to good advantage, but can also spoil an otherwise perfect shot. Things like wind in trees can produce ghostly effects that’ll have to be fixed up in photoshop later. Here is how Auto Exposure Bracketing looks on my Canon 30D.

Auto Exposure Bracketing (AEB) on a Canon 30D set to + & - 1 stop exposure
Auto Exposure Bracketing (AEB) on a Canon 30D set to + & – 1 stop exposure

Also remember you must be saving your images in RAW format. If you don’t have a cable release then set your camera to timer.. if you have AEB setup correctly 3 shots will fire off when the timer activates.. This is your ‘set’ of RAW images to make your HDR. You can either take note of the filenames of the file now

or…

2) Preview your RAW files

Use whatever image software you use to do this. Right now I am using a version of Adobe Lightroom (Public Beta 3.0, but you can download a trial version from the adobe site). Find your 3 RAW images and take note of them to load up in Qtpfsgui.

Normal Exposure RAW for HDR
Norm Exposure

This is a Under Exposure of my scene for creation of a HDR.
Under Exposure

This is a Under Exposure of my scene for creation of a HDR.
Over Exposure

Here are my 3 RAW files.. As you can see individually none of them look really fantastic. Now Find these 3 files on your computer and open them with Qtpfsgui.

3) Load your RAW files into QTFSPGUI.

Open qtpfsgui & select ‘New HDR’ from the main screen. It will take you to a window that looks like this.

qtpfsgui loading page
qtpfsgui loading page

Now either drag your images into the box below the ‘load images’ button or click that button & navigate to them where they are stored on your computer. Once that is done your screen will look like this.

qtpfsgui now has your 3 RAW images loaded
qtpfsgui now has your 3 RAW images loaded

For the sake of simplicity don’t bother changing these values. If you have the correct RAW files imported all is good. Now click ‘Next’ to see this screen.

Qt advanced settings
Qtpfsgui advanced settings

Again, these are advanced settings, so don’t bother changing them, just press ‘Finish’. Now your computer may spend some time processing, depending on how fast it is. Be patient and you’ll soon see a window like the one below. I wouldn’t even bother trying to zoom out or look @ your image just yet, because chances are it’ll look pretty awful. If you want to zoom press the ‘W’ key on your keyboard.

qtpfsgui is now ready for tonemapping
qtpfsgui is now ready for tonemapping (note: image has not been zoomed out)

This means you are now ready for the main (most exciting) step, Tonemapping. From this window click on the ‘Tonemap the HDR’ button on the qtpfsgui menu (it’s the one above the blue & green colored Histogram)

3) Tonemapping your HDR

This is the most exciting & creative step of producing a HDR image & is where all the magic happens.. If you’ve successfully come this far congradulations as you’ve done all the technical stuff & now is some time for fun. Tonemapping is a process by which the information is reduced into a more practical level. There are a whole heap of different methods to do this & i’m still experimenting @ this stage of HDR production, so again to keep it simple we will stick to one method.

Now if you clicked on on the ‘Tonemap the HDR’ button on the qtpfsgui menu (it’s the one above the ‘Histogram’) you’ll see this larger window open.

qtpfsgui tonemapping quick guide
qtpfsgui tonemapping quick guide

the RED Highlighted menu (Tone Mapping Panel) controls the different methods of HDR tonemapping. I usually like to use ‘MANTUIK’ as it produces nice results most often.
the GREEN highlighted menu (Tone Mapping Settings) sets the size of your render & applies the effect to produce an image. Use small images until you are satisfied with the result as larger image sizes take a long time to render.

Ok, so select ‘Mantuik’ from the Red menu & press ‘Apply’ from the green.. what you’ll see is a small preview of your HDR Image!! I Hope it turned out for you. Here is a screenshot of my 1st render, with default settings. My preview size is @ the default smallest size of 256×384.

 

qtpfsgui 1st render
qtpfsgui 1st render

I’m pretty happy with the result but first I am going to tweak some settings, bumping up Saturation & Detail sliders on the Tone Mapping Panel, & then hitting ‘Apply’ from the Tonemapping Settings to produce the window below.

qtpfsgui 2nd-render
qtpfsgui 2nd-render

Notice how Qtpfsgui opens up a new preview window with every render, it’s a handy feature as you can see the changes. My advice is to be gentle with the settings 1st, but extreme results can produce some great images. Now I’m happy with this image so I am going to render full size by changing the “Result size” in the Tonemapping section to the highest being 2348×3522. After I hit ‘Apply’ I am going to take a break & make a coffee because this can take a while (dependent on your computers speed). Here is my final render.

qtpfsgui final render
qtpfsgui final render

Note that I adjusted the view by pressing ‘W’ which is fit to window. We are almost there, all we have to do is adjust our levels, which should be easy if you already have experience working with digital images.

4) Adjusting levels of your HDR

The last step of this process is adjusting our levels. This can also be done in photoshop (i recommend a final touch up of your image in photoshop as some digital artifacts can result from this processing method) however you can also do this in qtpfsgui by selecting the ‘Adjust Levels’ button from the menu. Here is a shot of my screen with image levels adjusted to my liking.

adjusting qtpfsgui levels to my liking
adjusting qtpfsgui levels to my liking

I like my images dark & moody so tend to ramp up the black & mid tones of the levels, I also find this helps bring out the textures, but at the expense of more grain in the shadows so it is a bit of a balancing act. See on the screenshot how the black arrow of the levels is pulled in towards the middle of the bell shape. Levels are a whole other thing, that i’ll write a rough guide for, so if you are unsure just do what i’ve done in the previous image.

5) Results: The Final HDR Image

and Here is the final Image unadjusted. I would now go into photoshop & clean up certain parts for a very final image (some of the black has picked up some noise) but for such a simple method i’m more than happy with the results.

So have a go now & please post below links to samples of your results from this tutorial. Any questions will be answered & suggestions also well received! I hope you all have some fun making HDR images!


9 thoughts on “How to HDR”

  1. Sure, I think to do a ‘real’ HDR you need 2+ shots, as this adds ‘range’ to your image data. Of course you can digitally create a HDR from a single shot, but this is simulated not real HDR photography; The main issue being that pixels do not like being pushed; everytime you tweak levels & exposures in an image you introduce a bit more noise to it. HDR processing tends to amplify existing noise in images; hence the reason to shoot HDR with the lowest ISO settings possible.

  2. Best you should edit the post title A Simple guide to HDR photography using qtpfsgui | Pixelwhip.com.au to something more generic for your webpage you create. I liked the post yet.

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