Processing RAW using DxO - post your samples and tips - Part II

I use DxO Viewpoint 3 from within DxO PhotoLab 5 to do perspective correction on more than half of my images. DxO Viewpoint is a standalone product that you have to buy separately ($79), but it integrates into PL5 and looks like a built-in feature once installed.

For years I've been using a perspective correction tool to correct 'vertical' perspective - on city images. For example, if you shoot with the camera angled upwards, buildings look like they're falling backwards, and correcting vertical perspective brings the buildings' sides into parallel lines. I'd also correct perspective shooting interiors of properties before advertising them for sale or rent, so that the rooms' walls are vertical and parallel for a pleasant, balanced look.

DxO Viewpoint is great for this: it has a 'parallel lines' correction tool. Once selected, two parallel lines appear on the image, and you can move them around and change their angle, then 'Apply' the change and the image perspective will be adjusted and the lines will be made parallel.

You can also use a Viewpoint 3 'Rectangle' tool to correct not only vertical, but also horizontal perspective, stretching and compressing the image horizontally at the same time as vertically. This is really useful for adjusting perspective with wide angle and especially ultra-wide angle lenses, to make images look more 'normal' and pleasing.

Here's an example. I recently shot a vintage 'Dome' touring railroad passenger car on an Amtrak train that came through Tampa. I shot it with the EF-M 18-150mm lens at a wide angle of around 21mm. I shot from fairly close to the train in order to get some detail from the 'front' of the car and between the cars.

When processing, I wanted to 'stretch' the image horizontally to give it a more natural perspective, show more of the long car, and fit the image to 16:9 format.

Below are the 'before' and 'after images --- along with the rectangle perspective correction that I applied.

Stretching parts of the image can result in the stretched parts of the image appearing less sharp and noisier than the areas that aren't stretched.

I've found that the Canon M6ii's 32 MP sensor gives you more latitude in perspective correction than the 24 MP sensors (such as the M50ii), but correcting perspective works well with 24 MP cameras as well - you just can't stretch quite as far.

In the example below, I cropped the image quite a bit, and after stretching, the left side of the image was noticeably softer that the rest of the image.

I was able to bring the left side to about the same level of sharpness as the rest of the image by masking it with DxO Pl5 control points (covered in a post in the original DxO tips thread), and bringing up the sharpness of the masked region by 50.

The resulting image was a little noisier than the original, unstretched image, so I also increased the DxO Deep Prime Luminance value by 5 (from 65 to 70 so that the images appeared similar.

At first glance it may not seem like the perspective correction is that much, but when looking at both images, in the first, personally, my 'gaze' wanders around and then off the image, whereas with the lines and elements in the second image, my gaze quickly rests within the image in the center to the right side of the train car. (Camera club stuff LOL).

Not perspective corrected, only 'horizon' slider was adjusted

Rectangle perspective correction - left edge of image masked and sharpened 50 - +5 de-noise

Perspective correction that was applied

Sharpening Mask used to sharpen left side +50 after it was softened by the stretching