Creating HDR images using Automatic Exposure Bracketing

For most of my static photography I like to use automatic exposure bracketing, also known as Exposure Stacking or HDR (High Dynamic Range)

The reason for this is it gives much more detailed images as there is more detail over a higher range than with one image.

The way it works is it will take a sequence of images but at different exposure values that you can define in the camera.

For example I set it to take 3 shots with exposure values between -2 and +2. This will give me 3 images; one that is underexposed by -2 stops, one normally exposed shot and one that is overexposed by +2 stops.

The reason for doing this is that the underexposed shot will bring out more detail in highlighted areas (but detail in shadows will be lost) and the overexposed shot will bring out more details in the shadows (at the loss of details in the highlights) but when the 3 images are merged together you will get more detail in both highlights and shadows.

I also shoot in RAW which gives more detail in shadows and highlights so this helps things even more.

It is possible to do this manually but requires a tripod and very steady hands as you would need to go into the camera menu between each shot to change the exposure value each time but luckily in most modern DSLRs there is an option to set it up for you.

In some cameras as well there is a full HDR mode which will take the images and merge them in camera but from my experience it doesn't produce as good results as doing it (semi) manually.

The following steps are how I do it but there are other ways and software you can use to do it yourself.

This guideline is using my Canon 5D MkIII and Canon 7D MkII but you should find similar options within your DSLR.


Setting the number of shots.

As mentioned previously I use 3 shots but with my Canon 5D MkIII it is possible to shoot up to 7 shots although I find 3 is fine for what I want and if you are hand holding the camera the more shots the more difficult it is to keep the camera steady.

Bracketing sequence. (See Pic 1 Above)

This is optional and I actually changed it recently. What this does is simply decides the order in which the images are taken in camera and how they appear when imported. I chose 0-+ which means the first image will be the normally exposed one followed by the underexposed one and then the overexposed one. I chose this because when I am applying white balance etc to the images in post processing I can apply it to the 'normal' image which is first then sync the settings to the other images.


Setting the exposure increments.

As mentioned previously I choose to exposure by +/- 2 stops each way so to do this you go into the Expo.comp/AEB option in the menus and turn the top dial until the markers are both on the 2 position, you will see the points expand out as you turn the dial. In this menu you can also adjust the overall exposure using the main wheel and it will shift all points accordingly. On the Canon with 3 shots selected you can exposure up to +/- 3 Stops. If you choose more shots you get a higher range up to +/- 6 with 7 shots selected but this will vary from camera to camera. After you have selected your exposure range be sure to press the set button as this has caught me out before! One thing I have done also is to put the Expo.comp/AEB option in the 'My camera' settings. This is a customised menu you can use for your most frequently used options to save searching through all of the menus. That way I can quickly switch between single shots and bracketed shots

Taking the pictures.

Now that the settings are dialled in you are ready to take the shot. Here are some very useful settings to use.

If possible, use a tripod. When you process the images you need them to match up perfectly so the camera needs to be very steady.

Set the camera to its highest burst mode. This is especially useful if you are hand holding the camera (which I do 90% of the time) because the faster the burst mode is the less chance there is for movement in between shots. Also the camera is clever enough to know it is in AEB mode and it will only fire off those 3 shots if you hold the shutter button down and then it will stop until you release the shutter and fire off your next burst of 3 shots.

Use AV or Manual mode. You don't have to stick to this but I find that any mode where you have control over the aperture works best.

Important note: Don't let people look over your shoulder to see your pictures. If they see the underexposed shot or the overexposed shot they will think you don't know what you are doing :-)

Here is a sample of the images you will get they are not my best ones as I tend to delete the stacks when finished to save disk space so I had to find ones I hadn't deleted

Normal

Underexposed by -2 Stops

Overexposed by +2 Stops

Processing the pictures.


Now you are home after a full day of shooting and have a memory card full of bracketed shots.

For the processing I use Adobe Lightroom CC.

Once all of the pictures are imported into Lightroom do any tweaks you need to do such as setting White Balance, Contrast etc treating it like you would with your normal images. If you are going to sync the settings across multiple images I suggest you work on one of the normally exposed images so you can see the settings as you would expect. This is why I set the sequence to show the normal image first. 

You don't have to do it this way as you could always do it to the merged image but with the method I use the merged image will be a TIFF file so this is why I prefer to work on the RAWs first. You will still need to work on the TIFF afterwards anyway.

Once you have made the tweaks you want to there is a useful option where you can stack them together.

Choose 'Photo > Stacking >Auto-Stack by Capture Time and then choose a time that is low enough to separate all of the images into their stacks of 3. This can be a bit hit and miss and I strongly recommend you go through the images after stacking them to make sure they are stacked into 3s especially if you have been shooting burst shots of cars in action as they would need to be unstacked. This can be done easily by selecting the sequence and then right clicking on one of the sequence and choosing Stacking > Unstack.

Also make sure that you haven't shot 3 bursts close together as they may get stacked into a sequence of 6. If you get this you can select the first (or last) 3 of the stack and choose Stacking > Remove from stack . You can then select those 3 and choose Stacking > Group into stack. This will make more sense when you start doing it.

Important: Make sure you check and double check your stacks because the next step is going to take a lot of time so you want everything to be right before leaving the computer to do its magic. I have been caught on more than one occasion where I have gone to bed leaving the computer to process only to get up in the morning and find it failed 5 minutes after I went to bed because some stacks didn't match up.


Merging the images.


Recent versions of Lightroom have the ability to merge to HDR by choosing the sequence of images and selecting Photo Merge > HDR which works well but the only problem is you can only do one set of images at a time. If, like me, you have a lot of pictures from a full days shooting you want to automate this procedure.

To do this I use a Lightroom Plugin called LR/Enfuse (Click here for download page) which is an old Plugin but still works with the latest versions of Lightroom. Please note that it is donationware so if you like it please make a donation to the developer.

The good thing about LR Enfuse is that it will batch process multiple stacks so you can leave it to run (Once you have checked and double checked the stacks as mentioned before)


Using LR/Enfuse.


After installing the plugin (Instructions on download page) do the following:

Select all of your images in Lightroom.

Choose File > Plug_In Extras > Blend exposures using LR/Enfuse...

You can then follow the quick guide which can be found HERE for the settings but some things I want to note:

If you have used a tripod to get your shots you can uncheck the Auto Align checkbox in the Auto Align tab as it is auto alignment that takes the time when batch processing.

For the output type I recommend TIFF rather than JPG as although it is a considerably larger file size than JPG it will give you more to work with on the last steps without losing quality. (See my blog about JPGs for more info)

Other settings are down to your own personal preferences and its worth experimenting with those.

Once you have started the process running find something else to do or go to bed because if you have a lot of pictures and you have auto align set it is going to take a long time to process!

When complete you will have some nice new TIFF files sat next to each stack in Lightroom but there is still work to do.


Editing the TIFF files.


When you see the 'finished' TIFF files you may be disappointed as they will look quite flat and dull a bit like unprocessed RAW files but this is normal.

You should now play around with contrast, sharpness, highlights, shadows, clarity, white balance etc in Lightroom until you get the images exactly how you want them to be and most of this is down to personal preference but once you have done that you will notice how much crisper and more detailed your images will be.

One thing I do in Lightroom is, once I have got an image edited how I like I will sync the settings to all other images but bearing in mind lighting etc as you may need to adjust the white balance for cars shot indoors compared to outdoors and vice versa.

Also once I get some settings I am happy with I will save those as develop preset in Lightroom and give it an appropriate name e.g. Car Show Sunny Day. That way I can apply that preset to future collections of images rather than having to do it all from scratch each time.

HERE is a link on how to do this if you are not sure.

Here is the finished image from my example quality is reduced for upload and not my best work as it was an older picture before I had refined my skills.

Finished Image

If you don't use Lightroom or prefer to use different software for merging your images here is a link to various other recommended HDR packages


HDR Software


One important thing to note: HDR is a very powerful method to use but it can very easily be overdone and will then look terrible (trust me I am guilty of it) so when you do make changes don't go over the top otherwise the images will look unrealistic. I like to think if its done well people wont notice its an HDR shot but will appreciate the quality. If you find this information useful please share it and link back to my website. I will leave you with some of my recent HDR shots from Autosport International 2017


Happy HDR'ing Darren

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