Plane Focus

One important correction to keep in mind when trying to capture a flat surface is the Plane-of-Focus on the subject, relevant to your camera sensor. The image below is an important example of that and I discuss it in more detail below. This technique will greatly improved your documentary-style photo skills!

A photograph of the rudder, propeller and partial stern of a motorboat used in the Newfoundland fishery during the 1900s.
The rudder, propeller and partial stern of a motorboat used in the fishery in Newfoundland (photo taken at the Grand Bank Seaman’s Museum).
A diagram explaining the importance of keeping the camera sensor parallel to the planar surface of the most important part of the subject in the image.
Use this to visualize the concept here: The dashed lines are all equal length.

When you shoot onto a flat surface and you want to capture the surface – and other detail that projects in front of and behind that surface – you first have to get parallel to that surface – that is, your camera sensor or film plane, not you. You can have the camera mounted on a tripod and be standing a considerable distance away and trip the shutter remotely. The key here is to think planes that are parallel to each other.  Those two planes are the subject and camera sensor. Aligning them is a touch tricky and takes practice.

A screen capture of Camera Settings from Adobe Bridge
Camera Settings as read from Adobe Bridge

The above and below screen grabs offer more than enough information for you to decipher the challenges of getting a decently sharp photograph: wide open aperture, slow shutter speed and a ISO setting that’s as high as I want to go. Above, you can see the key data: f-stop, shutter speed and ISO, as well as the specs to which I saved the image after processing the raw file. Shown below is information about the camera and lens, if you’d like to know what I shot with.

…camera and lens information

For the shot – and because I was in a museum – there were a couple of factors restricting the ability to get an easy capture: low light, no tripod, limited space to name a few. I was practically sitting on the floor and using my eye to focus across the flat surface of the rudder. If you tilt the top of your camera in towards the rudder, the bottom of the camera, naturally, pulls away, and one section of the rudder goes out of focus, as does other elements of the image. And, vice versa. The same applies to the left and right side of the camera.

I didn’t worry too much about the lateral roll (left and right, around the axis of the lens), and if you inspect the image carefully you can tell from the out-of-focus background that I am rolled well to the right! However, the propeller is sharp – it extends well out towards me – as does the planking on the boat (you can see the loss of depth-of-field on the plank lines near the top of the image). I have some crop room if I don’t like the blurred lines of the planks, but I wanted to get the rudder, propeller, and attaching surfaces for the rudder in focus. Therefore, the reference focal point for the image is the plane of the rudder. All of it.

Low light impacted the sharpness of the image due to using a slow shutter speed. I added a bunch of sharpening and grain and tints and vignette, to name just a few of the after effects applied in Photoshop. I can see knocking out the background of this image and having a bit of fun in Photoshop or Affinity Photo, for sure.

Update: Here is a the shot that’s been further manipulated in another favourite editor of mine, Capture One

A photograph of the rudder, propeller and partial stern of a motorboat used in the Newfoundland fishery during the 1900s. This image was modified, including background knockout, in the excellent photo editing program Capture One.
This much cleaner version of the image was processed in Capture One, including the knockout of the background

Photo Focus Merge

On a recent trip I made two images of the same subject; one with the foreground in focus and the other with the background in focus. I settled on the image with the foreground in focus for future use in a gallery, article or print, as it conveyed a stronger message of the subject at hand.

A few weeks later while reviewing my images again, I thought to myself ‘What if I could overlay the two images and combine them to give me one in-focus image?’ The use of a tripod on the original shoot would have let me capture at a slower shutter speed and stop down to an aperture as small as f32, if necessary. However, I didn’t have it with me so, as they say, no use in crying over spilt milk! The image below focused on the background, with the rear of the boat not in critical focus.

Note: Click through any of the images for a larger light box view to see more information about the image and technique.

A photograph of an old boat and village in the background, with the camera lens focused on the background. This image is used here to show a technique in Photoshop known as Focus Merge.
In this image I focused on the background. Because the boat dominated the frame, this did not work for me.

I decided to try my luck with Google and search for ‘combine images, focus near, focus far.’ The search result Continue reading