LensTip.com

Articles

A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM

1 December 2009
Szymon Starczewski

4. Image resolution

As we mentioned in the introduction, the resolution of both lenses ( in the sense of the MTF50 function values) was tested based on RAW files from an A100 body. The measurement errors were in the 0.3 to 1.2 lpmm range and decreased on stopping down. The resolution graph for the frame center of both lenses is presented below.

A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution

Really, even taking into account measurement errors it is difficult to find a noticeable difference between these two instruments. The Sony seems to be a tad sharper at the maximum aperture, the Minolta – in f/2.0-4.0 apertures range. Apart from that, both lenses perform neck and neck. The differences are really slight and very difficult to notice in real pictures.


Please Support Us

If you enjoy our reviews and articles, and you want us to continue our work please, support our website by donating through PayPal. The funds are going to be used for paying our editorial team, renting servers, and equipping our testing studio; only that way we will be able to continue providing you interesting content for free.

- - - - - - - - - - - - - - - - - advertisement - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

The situation at the frame edge of the A100 sensor is shown in the picture below.

A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution

Here we are a bit surprised. It seemed that the Minolta, designed to work on full frame, would fare better than the Sony but it is clearly not the case. Both lenses perform again very similarly but near the maximum relative aperture and by f/5.6 the Sony clearly wins. As you see, the Sony’s significant dimensions and its huge rear element, definitely not smaller than that of Minolta, make the lens equal of the full frame Minolta, even a bit better.

Charts are one thing but it’s always good to check how the situation looks in real pictures crops. A quite vivid comparison (based on JPEG files) is presented below. In principle, it completely confirms everything written above.

Frame center – f/1.7 – f/1.8
Minolta AF 50 mm f/1.7
Sony DT 50 mm f/1.8 SAM
A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution
Frame center – f/5.6
Minolta AF 50 mm f/1.7
Sony DT 50 mm f/1.8 SAM
A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution

Frame edge – f/1.7 – f/1.8
Minolta AF 50 mm f/1.7
Sony DT 50 mm f/1.8 SAM
A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution
Frame edge – f/5.6
Minolta AF 50 mm f/1.7
Sony DT 50 mm f/1.8 SAM
A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution A history of Sony Alpha - Minolta AF 50 mm f/1.7 versus Sony DT 50 mm f/1.8 SAM - Image resolution