For a landscape photographer who’s goal is to produce large, impactful prints, image resolution and sharpness are critical considerations. The introduction in 2015 of high megapixel DSLR like the Canon EOS 5DS R provided for a significant step increase in sensor resolution, and brought along much discussion on what did that mean for the rest of the image capture system (lenses, supports, data storage, computer processing and so forth).
From a purely technical point of view, the small pixel size in the new sensors (approximately 4 microns) impacts several aspect of the capture:
- ISO sensitivity and noise: The smaller pixels collect less light, so maximum ISO sensitivity and noise suffer.
- Diffraction limit: The sensor in the Canon 5DS R out-resolves a theoretical lens with an aperture smaller than approximately f/5.6.
- Hyper-focal distance and Depth of Field: The smaller pixels require a smaller Circle of Confusion in order to capture a sharp image. As a result, the apparent depth of field of a lens/aperture combination is less.
- Control of camera shake becomes more critical: Canon did an excellent job dampening the shutter and mirror mechanism, but the resolution of the sensor is such that any minor motion during capture is enough to generate a soft capture.
The consensus internet wisdom (?) is that in order to take advantage of the 50 Mpix resolution the camera can only be used with the finest (and most expensive) lenses, on rock solid tripods with mirror lockup, cable release, and calm winds. For extended depth of field, multiple focus-stacked captures should be employed. While all of this without doubt would maximize the chances of a high quality capture, the practicality of photographing the Landscape under the elements sometimes requires the expediency of hand held capture with whatever lens is mounted on the camera (for me likely either the 24-70/2.8L or the 70-200/2.8 L IS II).
Over the Christmas 2015 break I had my first opportunity to practice capturing images without my trusty RRS TVC-34/BH-55 in Monument Valley, AZ. We had a short time to drive through the loop road, and very cold and windy conditions (felt like at least 40 Mph sustained).
The image below was captured handheld, with my 24-70/2.8L (first generation) at 32 mm/f11, 1/160s, ISO 400. In order to capture enough apparent DoF the lens was stopped two full stops past the diffraction limit, and the ISO was raised to 400 to give me a fast enough shutter speed to counteract the motion caused by the wind both on the subject and on myself.
At this resolution, this appears as a successful capture. Let’s look at the detail:
This is a 100% crop of the foreground, including both some dead wood (not affected by the wind) and some brushes. Note how the details are very soft, both in the fine structure of the wood and of the dried brushes. This is less than what one would expect from $5,000 of equipment, but is consistent with the limitation of both diffraction and micro-shakes that were inherent in the capture conditions.
This proved to be a great chance to try out a new (to me) piece of post production software, Piccure+.
Piccure+ implements a sophisticated de-convolution algorithm to compensate for both lens aberrations and micro-shakes. In this image the primary source of softness was the small f-stop, with a secondary contribution from the less than rock solid hand-held capture.
Piccure+ managed to recover a great amount of sharpness, as shown in the crop below:
The results are great and produce a file that is printable at 30″x20″ with almost no interpolation and with beautiful detail. It takes a few iterations through the preview window of Piccure+ to determine the right settings, and about a minute for Piccure+ to process the 50 Mpix TIFF out of Lightroom, but the results speak for themselves.
At $99.00, Piccure+ is a steal, especially when compared to the cost of the camera hardware! While I am usually fanatical about a perfect capture, Piccure+ allows me to obtain beautiful results even when the situation requires expediency. Highly Recommended!