July 18, 2008

Bracketing tutorial (HDR)

I promised to post a short tutorial on how to turn on bracketing on Canon cameras. I only have a 40D, but I used to have a 30D, and I've seen 350D. The menu systems, and the way that you turn on bracketing is almost the same om most Canon models.

Why do you want to turn on bracketing?

You will get a lot better results when you use Photomatix (or Photoshop) to create an HDR from 3 exposures. Extracting 3 exposures from one RAW file is pretty pointless since Photomatix can do that for you. HDR processing from one RAW file will work for certain images, but you will most likely get lots of ”ISO noise” in the dark areas of the photo.

So now you know why you want to take more than one exposure, but you still don't know how to setup the camera for more than one exposure.

First a photo of the back of a 40D.



You will mostly use the menu button (1), the setting button (2) and the quick control dial (3).

Step 1:

Press the menu button when the camera is turned on. Then navigate to a menu that looks like this:



The menu option that you are looking for is the one that is named AEB (if you are using English menus)

Select the option using the quick control dial, and press the settings button when it's selected.

You are then in edit mode. Turn the quick control dial clockwise till the 3 small dots are placed under -2, 0, and +2



Finally click the settings button again, so you get back to the menu. The AEB values should now look like this:



You are now done changing the values in the menus. Note that AEB will turn back to normal values when you turn off the camera.

Step 2)

This is an important step that you must remember to do. Switch to A-DEP (Automatic Depth of Field) or AV mode using the mode dial. Trying to take multiple exposures in other modes will most likely give you odd results.



You are now almost ready to take your first HDR photos using multiple exposures. Only one thing is remaining.


Step 3)

The camera is capable of taking 3 exposures in sequence if you hold down the shutter button and the camera is in one of the following drive modes:
Low-speed continuous shooting, High-speed continuous shooting, Self-timer 2-sec delay or Self-timer 10-sec delay.

I usually find it best to take HDR photos in High-speed continuous shooting if I'm not using a tripod or if there are moving people.

You switch to High-speed continuous shooting by pressing the DF*Drive button at the top of the camera, and then turn the quick control dial till your top display looks something like this:




The 3 rectangles with an H below indicates High-speed mode. Note that the display also shows that AEB is turned on.

Step 4)

Go out an take lots of photos! Do also note that you still can change the ISO setting, but it's usually best to take the photos at ISO 100 if you are using a tripod.

July 10, 2008

Just another sample HDR

This is the latest HDR that I have processed. It has more layers than I usually use, but that's because I had to correct lots of odd colors in the photo.

July 09, 2008

Next tutorial

The next tutorial that I will publish will be a more basic one. How to use a Canon 40D to take an HDR. (Turn on bracketing, and what you need to think about)

June 29, 2008

HDR Tutorial, Step 1, Photomatix settings

I have promised to create a short tutorial on how I process my images. I usually process landscape photos, but I couldn't find any nice ones on my disk (and I'm currently too lazy to go out). I decided to process a shot that I took in Peru, close to Machu Picchu. The outcome isn't the best, but I process almost all my shots in the same way.

Step 1, tone mapping the 3 exposures. (You can also use one exposure if it's sunny outside)

This is the settings that I usuall use. Note that the outcome usually have too bright colors, especially green and red colors tend to be too bright. We will fix that later in Photoshop.




Next step

HDR Tutorial, Step 2, identifying problems



This is what the image looks like after processing in Photomatix. We can see that it's ok, but there are some problems, e.g we can see pink / magenta lines along the side of the mountain, and there are also some green lines there. Those are Photomatix artifacts. The clouds between the mountains are also over exposed.

There are also some other things that I find disturbing, like the red leafes under the bush on the left side, and the small stones in the lower right corner.

The leafes and the stones are removed using cloning.












The magenta/pink and green lines that are artifacts from Photomatix.













First step
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HDR Tutorial, Step 3, adding some soft light

The first thing that I do after I have completed the cloning is to add a layer of soft light. The soft light usually gives the photo a better punsh. It's also quite common change the curve for the soft light so that it looks like an s-curve.

Adding soft light to the photo does however make it darker.










Soft light is a curve layer that is set to "mode" soft light.


First step
Previous step
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HDR Tutorial, Step 4, making it brighter

Adding soft light to the photo made the photo too dark, so lets add a levels layer before the soft light layer.



We make the photo brighter by dragging the middle triangle to the left. Keep dragging till you are satisfied.

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HDR Tutorial, Step 5, removing magenta/green lines

Tone mapping in Photomatix created a common artifact, magenta and green lines along e.g tree branches and mountains. Those lines are removed by adding layers of Hue/Saturation, each layer will be used to recude the saturation of a certain selected color.



The dialog above is displayed when you double click on the Hue/Saturation icon in the Hue/Saturation level. Note that we only wanted to reduce magenta colors, so we select them in the combo box at the top, and the we click in the image where a magenta line is. The color range will then automatically be set to only affect the selected color.

We do the same for the green lines, but the photo has lots of green colors that we don' want to affect so we need to use the mask.




The mask for the layer that affects the green colors has been used to only affect parts of the image (where the white lines are drawn)

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HDR Tutorial, Step 6, final touch

The last thing that I usually do before I resize the image is to add a curves layer to draw a vignette, and I might also add a curve layer in mode Screen to make certain parts of the photo brighter.



The final stack of layers can be seen above. It's now time to save, flatten the image, resize and apply smart sharpening.

The final result can be seen below.




That's pretty much how I process most of my photos. It usually takes about 20-30 minutes to process one image.

Good luck
Kaj


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April 20, 2008

A sample image

A sample image of what the end result of an HDR processed image can look like. The image has also been post processed in Photoshop CS3

'59 Ford Galaxie

The image is taken from my Flickr account.

Short description

Well, what to say in the first post of a new blog? Give a short description of the blog?

I'm not sure, but I don't think that I will update the blog so often. The reason that I created this blog is so that I can upload short tutorials on how I do the processing of my photos at Flickr. It looks like many people want to learn how to process HDR images, and to create vivid photos. I have till now answered questions through e-mail, but it gets to cumbersome, so here's a blog on it. :)