Landscapes Focus Stacking

1

LandscapesFocus Stacking

Landscapes Focus Stacking

2

A key aspect of successful landscape photography is image sharpness. Usually, it is desirable to ensure that all elements of a scene, whether close or far, are captured in sharp focus. This can prove to be challenging and, if not achieved with the click of the shutter, cannot be corrected later during post processing.

Landscapes Focus Stacking

3

One approach that is often taken is to use the smallest aperture available, e.g. f/22, to obtain the largest depth of field. Whilst maximising the depth of field is a good intent, using such a small aperture will actually result in softer images due to an effect known as diffraction.

Landscapes Focus Stacking

4

Most lenses are at their sharpest when used at apertures between f/8 and f/11 and whilst hypefocal focussing may allow you to capture an entire scene acceptably sharp in one image using these apertures; it is always still a compromise between a number of factors and there will be times when you cannot generate enough depth of field to capture a whole scene at optimum sharpness.

That is where focus stacking comes in.

Landscapes Focus Stacking

5

Focus stacking is the technique of stacking (or blending) a number of images that have been focussed at different points throughout a scene to give a final image that contains the sharpest portions of the originals, seamlessly blended into one. It isn’t as laborious as it sounds and can give really good results, rendering scenes far sharper than possible in just one exposure.

Landscapes Focus Stacking

6

Shoot it out

As you will be stacking the images into one, aside from the point of focus, you want the individual photographs to be identical in all other respects. Therefore, it is best to have the camera positioned on a tripod and use a remote release.

Landscapes Focus Stacking

7

Using your optimum aperture (can easily be determined for a given camera/lens combo using focus charts, however you will most likely find that f/8 is a good starting point), take the required number of images focussed at different points throughout the frame.

Landscapes Focus Stacking

8

A minimum of two images are required, i.e. one focussed for the foreground and one focussed for the background, however an additional third image, focussed for the middle ground can also be a good idea.

Landscapes Focus Stacking

9

FOCUS STACKING: LIMITATIONS

Focus stacking is an amazingly powerful technique, but it definitely has disadvantages:

• It can be very time-consuming.

• It usually requires the subject matter to be motionless.

• It may require a precision focusing device (such as a focusing rail) when large numbers of photos need to be stacked (such as with extreme macro photography).

• It requires specialized software to align and merge/blend the photos.

Landscapes Focus Stacking

10

CAPTURING THE PHOTOS

The most important decision with focus stacking is choosing how many photos to take. This is influenced by the following factors:

Landscapes Focus Stacking

11

In Photoshop, you can use either “File > Automate > Photomerge...” or “Edit > Auto-Align Layers...” as shown:

If you use Photomerge, then you can effectively perform stages 2 & 3 at the same time if you also check the box that says “Blend Images Togeth-er.” If the photos were taken on a tripod (as they should be), then it’s best to use the “Collage” option (shown on the right). If you’re using another soft-ware package, this is equivalent to making sure that the software only repositions and resizes the images when aligning them.

If you use “Auto-Blend Layers,” then you’ll need to first ensure that all your photos are already pasted on top of each other as layers in Photo-shop.

In Photoshop, if you already used Photomerge to align the images in stage 2 above, then these photos may have already been merged if the “blend images together” box was checked. Otherwise you can blend these as follows

You’ll be left with layer masks for each stacked photo (far right image above), so all you have to do is flatten the image (select all layers and go to “Layer > Flatten Image”) and you’ll be left with a sharp, extended depth of field photo. Just in case though, make sure to closely inspect the final result and edit the layer masks as necessary.:

Landscapes Focus Stacking

12

Thank You