Minolta MD-Rokkor X 45mm f/2
The Minolta MD 45mm f/2 is a common slightly wide and fairly compact standard lens.
The lens is from the time when they started making less expensive kit lenses. It is well made by today’s standards, but not as nice as some of the older manual lenses, like the cheap feeling plastic aperture ring (most of the lens is still metal though).
The lens has 6 elements in 5 groups, and has only a 5 bladed diaphragm. The minimum focus distance is a long 0.6 m (2.1 ft), but the lens is fairly light for this vintage lens weighing 125 g (4.4 oz).
Comments on the Results
The center resolutionI use the term resolution to refer to the MTF20I use the term resolution to refer to the MTF20 graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. graph. This is how well the lens can resolve fine detail, but the contrast is low at this point. is pretty good wide open, better by f/2.8, but shows a huge step up at f/4. The corners are good/very good by f/5.6.
Lateral CADifferent wavelengths (colors) of light have different magnifications and produce colored halos around high contrast objects near the frame edges. isn’t well controlled for a prime like this lens, showing about 2 pixels across the range. This will be visible in some circumstances or zoomed in.
ComaPoints of light are distorted near the edges of the frame. A circular point of light might be more comet shaped. and astigmatismDifferent angle edges have different focal points. A picture of an X might have one / of the X sharper than the other \. Has the appearance of slight motion blur or softness, and tends to be worst at the edges of the frame. aren’t bad, but there is some deformation of the bokeh circles in the corner wide open.
I didn’t specifically test this lens for flareInternal reflections on the lens elements causes ghost images and other artifacts to appear in the captured image. Most common is internal lens elements and diaphragm shapes will show when a bright light source like the sun is in or near the frame., longitudinal CADifferent wavelengths (colors) have different focus points, causing colored halos in out of focus regions of the image; typical is magenta in front of focus plane and cyan behind., or take sample shots.
Pros and Cons
- Compact Size
- Extreme Corners
- About 1 f/stop behind