What is focus stacking – and why I use it

“How do you get your macro photos so tack sharp from front to back?”

That’s a question I get asked often. The answer is simple: focus stacking. In this blog, I’ll explain what stacking is, why I use it, and how I include it in my workflow. I’ll also share tips and photo suggestions to help you try it yourself.

So, what exactly is stacking?

Focus stacking (or just stacking) is a technique where you take multiple photos with slightly different focus points. These images are then blended together into a single photo that’s sharp across the entire frame – from foreground to background.

Your camera simply can’t keep everything sharp at once when shooting up close, like in macro. Stacking solves that problem.

When do I use stacking?

I mainly use stacking for macro and nature photography, when I want all the details – from the front petal to the back antenna – to be sharp. Think of subjects like:

• Close-up flowers
• Insects or butterflies
• Textures like moss or mushrooms

But stacking is also useful for still subjects in a studio setting – product photography or even a detailed portrait close-up of an eye, for example.

💡 Tip: Make sure your subject doesn’t move. Wind is the enemy of a clean stack.

How do you create a clean stack?

I prefer to work with my Canon EOS R5 combined with the RF 100mm or RF 35mm macro. I focus manually or use the focus bracketing function (if the camera supports it). I prefer manual because it lets you control the focus shift size more precisely.

1. Use a tripod or stable surface

A solid tripod or surface is essential. Even the slightest movement can ruin your stack.

2. Focus manually

I move the focus point in small steps, starting from the part closest to me. This can be done manually or with a macro rail/slider.

3. Take multiple shots

Depending on the subject, I take between 5 and 30 images. The shallower your depth of field, the more steps you'll need.

4. Use Manual Mode (M)

When shooting in Manual (M), your shutter speed, aperture and ISO stay constant for every frame in the stack. This is key for a seamless result because:

• With changing settings (like in Av or Tv), exposure may vary between frames, causing flicker or color shifts when blending.
• Consistent settings ensure smooth transitions between focus layers.
• You maintain full control over exposure and depth of field – crucial for precise work like macro stacking.

5. Merge using software

I use Adobe Bridge to send my selected stack files to Photoshop. Go to the folder with your images, select the entire focus stack, then use: Tools → Photoshop → Load Files into Photoshop Layers...

Once the images are loaded as layers in Photoshop, select all layers and go to: Edit → Auto-Align Layers... and choose the “Auto” option. If you have a large stack, this might take a moment.

Next, we blend them. Go to: Edit → Auto-Blend Layers... and choose “Stack Images”. Also enable Seamless Tones and Colors and Content Aware Fill Transparent Areas.

The end result: a single image with your subject razor sharp from front to back!

Common stacking pitfalls

• Movement – If your subject moves (wind, crawling insects), you might end up with ghosting or blurry areas.
• Focus jumps – If your steps are too big, you’ll get ‘soft gaps’ between focus layers.
• Noise – More images can result in more visible noise after blending. Lightroom or Topaz DeNoise can help clean this up.

💡 Tip: Watch out for insect movement – sometimes a wing or leg will shift just enough to ruin a stack. Be patient or try again.

Setting up Focus Bracketing on your Canon (e.g. EOS R5):

1. Switch to Manual Mode (M)

Manually select your aperture, shutter speed and ISO. Use a sturdy tripod.

2. Go to the menu → select the ‘Shooting’ tab (red camera icon)

• Find the option: “Focus Bracketing”
• Set "Focus Bracketing" to "Enable"

• Now adjust these 3 settings:

  • Number of shots
    → Start with 30–100 (depends on subject depth)
  • Focus increment
    → Start with 4 or 5 (lower = smaller steps = more precise)
  • Image merging (on some models)
    → If your camera has this option (like the R7), set it to Off if you plan to stack in post.
• Focus on the nearest point of your subject (Live View or touchscreen works great)
• Press the shutter – the camera will automatically capture the full sequence

So, is stacking for you?

Stacking takes a bit more time, but the reward is huge. You’ll get razor-sharp, detailed images that simply wouldn’t be possible with a single shot.

Whether you’re photographing a flower, mushroom or insect – stacking gives your photos a professional and technically sharp look that stands out.

My advice: give it a try! Start indoors with a still subject and experiment with the number of shots and focus steps. You’ll be amazed at the result.

Questions about stacking, my workflow, or how I edit the final images? Feel free to drop a comment – I’d love to help!