The Minolta MC Rokkor-PF 55mm 1:1.7 was introduced in 1968 and it was always an affordable lens. Today it usually sells for around $20 at ebay.com (affiliate link).
I like it because it has very nice bokeh, the nice focusing feel and the small size. I is not one of my sharpest manual lenses, the Canon FD 1.4/50 for example is noticeably sharper but it has very nice character, not far away from the much heavier and more expensive Minolta MC 1.2/58.
The Sony FE 1.8/55 ZA was introduced 45 years later in 2013 and it costs around $1000 or 50 times as much as the Minolta. It has received very positive reviews and is considered to be one of the best normal lenses available today.
The question I try to answer with this test is: How different are the results I can expect from the lenses? I will look at smaller images optimized for the web but also at 100% crops to judge print quality.
All images are developed from raw and I used a tripod unless I mention otherwise. Please click on them to see them in full size (1500px wide).
Scene 1: Bokeh and Sharpness in the center wide open
The same settings applied to the image taken with the Minolta 1.7/55
Obviously the Minolta has less contrast. So I increased contrast in Lightroom to match the result of the FE55:
Viewing the images at 100% it is obvious that the Zeiss has more micro contrast:
But with some additional post processing the difference becomes much smaller because the Minolta can resolve the fine detail and contrast can be added in post. This comes at the expanse of some additional noise:
So what can we take away from this first scene?
The Zeiss has smoother bokeh but it also shows some onion rings because it has aspheric elements.
With some processing smaller prints and images for the web will be very sharp with both lenses. But even bigger prints will only be a little sharper with the Zeiss.
Scene two: Off center sharpness wide open
We already know that the Minolta is less contrasty so I won’t show the image, but what about off center sharpness?
ouch! The Zeiss is a lot sharper than the Minolta and unlike in the center of the image I can do nothing to change that because resolution isn’t there.
Minolta 1.7/55 | f/1.7
The Minolta transmits more light and vignettes a bit less that the Zeiss.
Scene 4: LoCA
For this test I matched the output, different processing
Scene 5a: Flare Resistance
Not unexpected but the Zeiss performs great while the Minolta loses a lot of contrast and shows a big flare. But keep in mind that this is a worst case scenario. You can get nice results with the Minolta, even when shooting into the sun.
Here is another scene:
While the Zeiss shows remarkably little flare I like the Minolta image better, the human eye isn’t free from such defects either and the Minolta image feels more natural to me.
Scene 6: Sharpness at f/8
I find it very hard to see any difference at all between the two images, colors are a little different (nicer on the Minolta if you ask me).
As you can see in the image the Minolta is a bit smaller but not by much if you include the Novoflex adapter and weight is not that different as well. So both lenses are well balanced on the a7.
The Minolta has an aperture ring which makes stooping down from f/1.7 to f/8 a bit easier than on the Zeiss were this takes a lot of scrolling.
In my opinion manual focusing works much better with the Minolta, it has a very smooth focusing ring which is a joy to use. The FE55 in contrast is focused by wire so the focusing ring is not coupled mechanically to the focusing mechanism but electronically. Focusing feels sluggish and it takes me more time to focus.
I am much more skilled in using manual focus than AF so I find it hard to comment on the AF performance of the Zeiss. It is reasonably fast when it’s brighter and slows down noticeably when it’s darker. I get more consistent results when I use manual focus with a manual lens but I am not an unbiased judge here because I prefer manual lenses in general.
I think you can read the results in different ways.
The Zeiss is, in a technical sense, better in most aspects and the difference is very obvious when it comes to sharpness outside of the center at f/1.8 or flare resistance. AF will be a very important argument for most people as well. So when you rely on either of these the Zeiss will be the obvious choice for you.
I, on the other hand, don’t see much of an advantage for the Zeiss in my typical photography. The images I print bigger are rarely photographed at f/1.7 but at apertures were both lenses perform very similar. And for smaller prints and web images you won’t see that the Zeiss is sharper t f/1.8. And I find the Minolta more pleasant to use because it has a real focusing ring. But of course there are situations were I feel limited by the Minolta.
So depending on the photographers needs the Zeiss can be anything from a whole lot better to a little better.
You can buy the Minolta MC 1.7/55 at ebay.com (affiliate link) for around $20 and support my blog that way.