First Thoughts
Several months ago Phase One recently released an autofocus version of its venerable 120D f/4 MF Macro. As the 120D MF has been a staple lens for many photographers and one of the sharpest lenses in the Phase One lineup, we wanted to put the two head to head in a quick shootout.
Before we get to the test images, below is a spec sheet highlighting some key changes and differences between the two lenses at a glance:
[TABLE=68]Despite the close numbers, a feature that doesn’t show on paper is the 120mm AFʼs updated metal lens hood with a rubber coated edge.
On the AF lens, autofocus is engaged by simply sliding the focus ring forward, revealing the word “AUTOFOCUS” on the lens barrel. The 120mm AF also employs a focus limiter feature that can be engaged with a switch on the side of the lens.
Our Test
For this test, we wanted to focus specifically on sharpness and overall image quality. We set up a basic still life scene with controlled lighting and locked down the tripod for a straight forward lens swap test. F/16 was selected because depth-of-field in macro photography is always a challenge and while f/16 may be slightly affected due to diffraction it is commonly used to gain practical depth of field.
- Camera: Phase One 645DF
- Digital Back: P65+
- Software: Capture One Pro (tethered w/ default settings)
- ISO: 50
- Shutter Speed: 1/100
- Aperture: f/16
During these tests, we found it best to engage the autofocus a minimum of 3-4 times in order to confirm that focus is achieved accurately. The limiter function was not used. The 120mm MF lens was focused over several frames by viewing 100% crops using the Focus tab & Focus Mask in Capture One to achieve as close to the same focal plane as the 120mm AF lens as was possible.
NOTE: The AF lens exposure was adjusted -.1 while the MF was boosted +.5 to even the exposure on all test photos.
Full Scene MF
Full Scene AF
100% Crop MF #1
100% Crop AF #1
100% Crop MF #2
100% Crop AF #2
NOTE – Phase One has yet to release a datasheet for the new lens, so as soon as we can get our hands on that we’ll happily share that in comparison to the existing data for the 120MF and compare the data directly to real world images.
Conclusions
This test was specific to image sharpness at f/16 for both lenses, we will be expanding on this test with an in-depth diffraction test, as well as comparing the minimum focusing distances of both lenses. Also, seeing that many photographers may use this lens as a portrait lens, we’ll also use more typical portrait focusing distances and apertures to re-evaluate the sharpness and overall image quality.
In Stock
We have 120mm AF lenses in stock; they can be ordered through our eStore or by calling us at 1-877-217-9870.