Lens Optimisation - Update
Can fine tuning or calibrating your equipment really make a difference?
In real world scenarios, YES, the difference can be game changing. All photographic equipment regardless of cost and brand are made to manufacturing tolerances, these tolerances, be it with the body and or lens, can make the difference between capturing soft or pin sharp images.
Changes made as a result of fine-tuning your equipment, are only half the story though. To ensure you are able to achieve the maximum out of your equipment, we would always recommend undertaking a lens optimisation on your lenses.
The calibration test is always undertaken at the widest working aperture of your lens as this is where any issues are most noticeable and thus compensated for. However, very few, if any lens, will perform best at its widest aperture. It is often necessary to "stop" down the lens for maximum performance, this often requires you finding the "sweet spot", as in the correct aperture to ensure the maximum resolution from your lens.
So how do you ascertain your lens sweet spot?
After calibration of your lens, we are able to conduct an automatic batch of tests, in which images are recorded at every lens aperture and the data analysed to determine the following:
- The aperture resulting in the highest resolution / sharpest images (often referred to as the “sweet spot”).
- The aperture that performs with the lowest captured resolution
- Working aperture range, this is the range of apertures that give the best combination of sharpness and usability.
The results are unique to your combination of camera / pixel count / lens and calibration correction, and the results as unique as a “digital” fingerprint.
This is why, we often refer to performing a calibration of your camera and lens without undertaking a lens optimisation as only half the picture, an analogy we often use is fish without the chips.
Following on from this, we often receive surprised and confused responses from clients when performing lens optimisation tests on their lenses, especially with expensive prime wide, standard and telephoto lenes, after all, a lens like a Canon EF 1.2L series lenses should perform best wide open, otherwise why would they produce such a fast aperture and expensive lens?
As much as for performance, the benefits of using fast / wide aperture lenses such as Sigma’s 35mm F1.4, Canon / Nikon’s 50mm F1.4’s, Canon’s 50mm F1.2L etc is that they allow for a brighter image in the viewfinder, to aid with composition and focusing in low light.
However, as we have found these lenses and others do not always perform to their optimum when used wide open and often have to be stopped down to overcome the fact that they are often soft when used wide open.
Another consideration is the age of the lens, a lot of the fast / wide prime lenses can be as old as 20 years and produced in the days of film or lower pixel digital bodies. When using these lenses on the modern pixel monsters of today they do not perform in the same way and any aberration is more obvious.
LENS OPTIMISATION ON SIGMA 35MM F1.4 ART
The example as shown below is a Lens Optimisation test using a Canon EF 50mm F1.2L + Canon Eos 5D Mk IV, a lens which costs £1500 and is 15 years old.
In the example as shown below a Nikon 85mm F1.8 G series lens is used with a Nikon D850. This lens is over 9 years old and at the time of production pixels count cameras such as the D850 where not even imagined.
Lens optimisation tests are also applicable for telephoto zooms lenses too. In this example a Canon 70-200mm F2.8 L series lens, which you would think would perform best wide open at F2.8 as opposed to F4 / F5.6 here.