DxO PhotoLab

Crop your photos with DxO OpticsPro 9

In collaboration with Christophe Gressin

In this tutorial, we will explain how you can crop your images to achieve a better composition and how to take into account certain technical constraints that can make it necessary for you to crop your photo during processing.

To follow this tutorial, you will need:

  • DxO Optics Pro 9, Standard or Elite edition (depending on your camera).
  • Some photos, preferably in RAW format.

1- Framing and image composition

A few definitions and principles

Framing and composition are obviously tied together, but are still two distinctly different.

Framing defines the periphery or perimeter of the image, and composition is the organization of the different subjects within your photo; thus each element is at the service of the other.

The first principle of composition is what is called the “rule of thirds”: imagine two horizontal lines and two vertical lines which divide your image into three equal parts both horizontally and vertically (for a total of nine rectangles): these are the lines of visual power, and the intersections represent the four strongest points in the image. Whether physical or virtual, the subjects in your image should be positioned on these lines or points to make them stand out and to bring good balance to your photo.

The sense or direction in which people visually scan photos is important to take into account. Westerners “read” a photo from the lower left corner to the upper right corner, so for them, it is more natural to have their gaze attracted more to the right than to the left.

In addition to this general direction, one’s gaze is also guided by the different lines in an image, whether physical (a path, a stream, a wall) or virtual (a look, the orientation of a subject such as a flower). This said, it is better that one’s gaze is not stopped in mid-tracking by certain elements, such as by a wall or building. So it is important that your composition take into consideration these factors so as to guide the reading of the photo in the chosen direction.

Thus framing encompasses the composition and defines its limits. Even if the “standard” format is that of a 24×36 sensor (in other words, 2×3), it is nonetheless possible to choose alternative formats — for example, square format (1×1) or panoramic formats (2×1 or 3×1).

Why crop during processing?

We use zoom lenses, we can switch lenses, so why not just frame the shot right when we take the photo? There are several reasons why this isn’t always possible.

First of all, sometimes we’re simply not shooting with the right lens. Second, sometimes the camera viewscreens are smaller than the sensor, and sometimes the sensor preserves information that we’d rather not save.

Further, sometimes we change our minds about what we think is pertinent or interesting in our shot, so we modify the framing so as to achieve a better result or different rendering.

The last case can be planned ahead of time: for example, when saving a panorama, if you know ahead of time that you’re going to want to end up with a photo in square format, you will b able to frame your shot in a way that will let you achieve the expected result.

Finally, certain correction tools require cropping: not just the corrections of any lens flaws, but also the correction of perspective problems or volume deformation. These kinds of “destructive” corrections necessitate shooting a photo with a sufficiently large frame to accommodate any adjustments during processing.

Let’s see how you can use DxO Optics Pro 9 to optimize your crop.

2- Cropping your photos

Step 1: Activate the tool

The crop tool is the last (or bottom-most) one in the Essential Tools palette:

To activate the Crop tool, click on the tool button  .


For quicker access, the tool is also available in the toolbar above your image.

Here is what your window will look like after you have activated the tool:

Step 2: Adjust your parameters

The tool parameters are displayed on the bottom of the page underneath the photo.

You can choose to superimpose a grid on your that will help you visualize the rule of thirds while you are cropping your photo, by checking the Display grid box. (Uncheck the box to hide the grid.)

Next, choose your proportions by activating the Aspect Ratio drop-down menu.

To crop while respecting your photo’s format, choose the option Original in the Aspect Ratio drop-down. You can also opt for free-hand cropping by choosing Unconstrained, or you can choose among different pre-defined ratios.

In the latter case, automatic cropping is offered so as to keep the most important part of your image within the selected proportions.

This is what you get with a 1:1 aspect ratio:

Step 3: Crop your image

The easiest solution for cropping an image is to take the original image and reduce its size. To do so, move the cursor onto one of the “handles” located in each of the corners and in the center of each line at the edge of the image; the handle you select will look like a double arrow reflecting the direction of movement during the operation.

For example, if you select a handle on one of the vertical edges, this is what you will see:  ; the handle in the upper right corner looks like this:  .

So by reducing the size of the image from the right side, you can end up with this, for example:


The illustration above was made using the Original option in the Aspect Ratio drop-down. As you can see, reducing the width also simultaneously reduces the height, with a shared impact between the top and bottom of the image. The same reciprocity occurs if you reduce the height: the width is proportionally affected.

Rather than changing the original framing, you can instead choose to redefine it. To do so, place your pointer outside of the image edges, close to one of the edges of the framing that you’d like to achieve. In this case, the cursor will look like this:  .

Click on and then pull it towards the image to define the new framing.

Step 4: Correctly position the new frame

The part ofthe image that is inside the new frame will be displayed normally, and the part(s) to be cut will be slightly grayed out. When you pass the cursor over the image, it will look like this:  .

You can correctly position the frame by clicking on it and holding down the mouse button as you make your adjustments.


Use the grid to help you correctly position your subject with respect to the “rule of thirds.”

Step 5: Adjust the size of your frame

You can also change the dimensions of the frame; to do so, place the mouse pointer on one of the handles (in the middle of each edge and in any corner) of the new frame and enlarge or reduce the size of the frame.

You can also define a new frame by clicking outside the frame, as in step 3 above.

Finally, you can also modify the proportions on the fly; the frame will adjust automatically.

Step 6: Validate your crop

Click on the Close button on the lower right of the image to validate your changes.

The Reset button takes you back to the original framing.

3- Cropping tied to correcting perspective or volume deformation

When you use perspective correction tools, you will unavoidably end up having to crop your photos. You can let DxO Optics Pro manage the cropping entirely, or you can manually adjust the automatic crop.

Step 1: Correct the perspective

We are going to use the parallel correction feature here. To do this, select the corresponding tool button  in the toolbar; on the top image, position the two straight anchor lines on each of the edges of the wall. You can preview the results in the image below.

You can make the rendering look a bit more natural by adjusting the High/Low slider value; set it here to +20.

You can see that the correction necessitates some cropping.

Step 2: Crop automatically

DxO Optics Pro offers automatic cropping for this type of correction. For this, go into the crop tool palette, open the Correctiondrop-down menu, and choose Auto, based on Perspective/Horizon.

The correction takes place automatically:

Of course, you can also manually crop your image by following the steps described in the preceding section.

4- Going further: free-hand cropping

We have shown you the crop tool using predefined standard ratios, but even if it’s not generally recommended, you can also crop your photos free-hand.

Especially when you apply a perspective or volume deformation correction and you haven’t left yourself enough room to have taken into account the inevitable cropping, you may want to reconstitute some of the lost parts by using such tools as Adobe® Photoshop® or Adobe® Photoshop® Elements®.

For more information about this type of operation, we recommend that you follow this dedicated tutorial, which will provide you with several methods for manually recropping your images after correcting them.

Photo credits: Christophe Gressin