Create Long Exposure HDR With Blending

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Long exposure images are one of a kind for me.

It often gives me a sense of serenity and calmness.

The milky smooth water and the silky sky instantly draw attention towards the center of the image.

When coupled with dark grey tones, the spellbinding contrast is almost irresistible to anyone.

One of the issues with long exposure is over-exposure in other areas of your image. This can be counter-balanced with exposure blending.

I didn’t really start shooting long exposure until I’ve invested in the Lee Big Stopper (10 stop ND filter) a few years ago.

I’ve learnt a lot and still continue learning from others.

My approach to blending in long exposure follows these 3 steps:

  1. Choose a base image
  2. Blend the parts in
  3. Further post-processing

I’m sure there are other ways or workflow to do it, but this is my way 🙂

blending long exposure
The final blended image

How To Achieve Long Exposure

It’s not very technical at all to create long exposure images.

Here’s what you need to do:

Drag down the shutter speed and maintain the correct exposure.

And there are basically 2 ways to do this:

  1. In aperture priority mode, keep the ISO at 100 (or as low as possible) and crank up the aperture to the maximum (e.g. f/22).
  2. Use an ND filter in bulb mode.

The first option doesn’t always work well especially in bright daylight. Your shutter speed may not be slow enough to create the long exposure effect.

Now the second option.

Shoot in Bulb Mode

To extend the shutter speed beyond the standard, you need to set your camera to bulb mode and use a remote release.

This allows you to keep the shutter curtain open as long as you want.

Use An ND Filter

This is the secret to creating long exposure images.

Invest yourself in a quality ND filter, such as the Lee Big Stopper or the Formatt-Hitech Firecrest 16. It stops down the light by 10 stop and 16 stop respectively, allowing you to increase your shutter speed for exposure compensation.

To be completely honest, it costs.

But the money is well worth the investment in the long run.

Try to avoid the temptation of getting a cheap ND filter because it will compromise the quality of your image. These are cheap for a reason!

Bracketing Exposure

Apart from the long exposure, you’ll also need images exposed for other parts of the frame.

A long exposure to smoothen the water surface may leave the sky or other elements over or underexposed.

You can then blend these in during post-processing to recover the details.

Learn More: The Ultimate Guide To Exposure Blending.

bracketing exposure for long exposure
Bracketed exposure for the long exposure image

Exposure Blending In Long Exposure

Blending a long exposure image is no different from any exposure blending.

Here’s what I do.

Choose a base image. I often use the long exposure image as the base to blend other parts in.

Why is that?

I find it easier to blend in the smaller parts than blending in the larger area with the long exposure effect.

But there’s more.

I can also utilize the advantage of luminosity masks to blend in the shadows and the highlights smoothly.

Here’s to show you how I blended the long exposure image that I showed above.

#Step 1: Choose A Base Image And Optimize It

long exposure base image

Start with the basic: auto-correct for lens profile and chromatic aberration. All you need is to check the boxes if you’re using Adobe Lightroom.

Depending on your image, you can correct the highlights or the shadows a little.

For this image, I brightened up the water surface a bit.

Remember to focus on the parts with the long exposure effect only. Because others will be replaced after blending.

#Step 2: Blending Other Parts Into The Long Exposure Image

blended rocks to long exposure
Blended in foreground elements

Using luminosity masks, I subtracted darks 4, 5 and 6 from darks 2 mask.

This was used to blend in the brighter exposure to recover shadow details on the rocks.

blended in the sky to long exposure
Blended in the sky

Finally, I used luminosity masks again to blend in the sky. I used a brights mask and painting-a-mask technique.

#Step 3: Further Post-Processing

Having the final blended image shouldn’t be the last step in your workflow.

In fact, it’s just the beginning.

You should treat the blended image as the “Raw file” and start your usual post-processing workflow.

Here are 2 adjustments that you can apply to any long exposure images to enhance their visual effect.

Enhance The Effect of Long Exposure With Tonal Adjustments

enhancing the effect of long exposure
Whitening the water surface

Whether you created a long exposure for the water surface, clouds or light trails, you can apply simple adjustments to highlight the effect.

2 of my most favorite methods are Levels adjustments and dodge and burn.

In the Levels adjustment tool, you can move the highlights arrow to the left or the midtones arrow to the right to increase the highlights.

This makes the white whiter and the lights brighter.

You can do the same with dodge and burn, which gives you more creativity and flexibility.

Use it with a brights luminosity mask to limit your adjustments to the highlights only (use subtract dark masks technique for the shadows).

Darkening The Shadows

Darkening the tones of the shadows means there is more contrast for your main subject to stand out.

And here’s the secret:

Create dark grey tones instead of black.

In color psychology, when grey gets closer to black, it conveys drama and mystery.

How to do that?

All you need is the Levels adjustment tool in Adobe Photoshop.

Create Dark Grey Tones With Levels Adjustment Tool

levels setting to darken tones
Use output levels and midtones to create darkened grey tones

Once you’ve applied a Levels adjustment layer, move the black arrow in the Output Levels to the right.

You only have to move it a slightly to shift the output levels for the shadows.

What this does is to set the darkest dark to a slightly lighter dark (which is essentially darker grey).

The next step:

Move the midtones arrow towards the right to darken the shadows to the new output levels until you’re satisfied with the results.

Check The Histogram

darkened tones histogram
Histogram showing peak in the shadows

Use histogram to guide you on how much to lighten the darkest dark to create a darkened grey.

The trick is to play with the output levels for the shadows and the midtones so that the peak of the histogram is in the shadows (area within the arrows).

Pay attention to avoid any shadows clipping.

And that’s it. Simple 🙂


Creating a long exposure image may take more time but the results are often well worth the effort.

Just remember the 3 steps: Pick a base image, blend in the parts and further post-processing to enhance the image.

For more tutorials on blending, please check out the exposure blending resource page!

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