This is the second review in a series on Minolta's manual focus normal lenses, to see the first in the series, click here.

When investing in a Minolta manual focus system one of the first lenses commonly purchased is a 50mm f/1.4 lens. The reason for this is that it is fast, sharp, and with brilliant contrast, while at around $50 it is about a quarter of the price you might expect to pay for the faster f/1.2 lens.

Due to the popularity of this speed and focal length the 50mm f/1.4 was manufactured for a long time, from its first introduction as an MC lens in April 1973, right through to the end of the Minolta manual focus system. The lens design went through considerable changes over that period, as detailed below:

April 1973 - Introduction of the 50mm f/1.4 MC Rokkor-PG. The lens used the same optical formula as the 58mm f/1.2 and weighed in at a more reasonable 305g compared to the f/1.2's 478g. It has outstanding build quality, and with its big (but not bulky) design it is an absolute pleasure to use.

August 1977 - Minolta introduced the 50mm f/1.4 MD Rokkor-X. It was the first wholly new lens designed for the MD system, and while it retained the 7 element, 5 group optical construction of the MC lens it was a more compact design, slightly shorter and 60g lighter at 245g.

April 1979 - A new 50mm f/1.4 MD Rokkor-X lens is introduced with an optical formula of 7 elements in 6 groups based upon that of the 50mm f/1.2 that was introduced in March 1978. The weight of the lens was reduced to 220g, and the filter size dropped from 55mm to 49mm

June 1981 - The existing 50mm f/1.4 lens was updated to a late MD cosmetic design (aperture ring lock, focus scale in orange not green etc.). The lens weighed an extra 15g at 235g, but otherwise was unchanged from the MD Rokkor-X version introduced in April 1979.

(Source: Justin Bailey's "Minolta Lens Chronology"- http://www3.ns.sympatico.ca/mciepl/chronology.htm - an outstanding resource)

The lenses being evaluated in this test are examples of the first two incarnations, being the 50mm f/1.4 MC Rokkor-PG and the 50mm f/1.4 MD Rokkor-X (both with 55mm filter threads). An example of the later design was unavailable for the test, but I have previously tested the 50mm f/1.4 MD and at that time I found it to be inferior to the MC version. This finding was in line with the opinions of several other collectors and testers, and accordingly I believe there is a consensus that the earlier designs are better performers in terms of resolution.

50mm f/1.4 MC Rokkor-PG

vs.

50mm f/1.4 MD Rokkor-X

The 50mm f/1.4 MC Rokkor-PG is one of my favourite Minolta lenses, and battles it out with my 50mm f/1.2 MD Rokkor-X for time on my camera. We have already seen how the 50mm f/1.2 performed, so I am interested to see how it compares with the MC f/1.4. Whatever happens, one is going to be getting the lion's share of time on the camera in future.

I am particularly interested in evaluating the bokeh of the 50mm f/1.4 MC Rokkor-PG. We saw in the f/1.2 test that the 58mm lens, while not as quite as sharp as the 50mm f/1.2, had much more pleasing bokeh. With the same lens design it will be intriguing to see if the 50mm f/1.4 lenses maintain that superb out of focus rendition. Anyway, enough preliminary discussion, and let's get down to business!

Above we can see the performance of the two lenses from centre and corner crops at f/1.4. Results show excellent detail given that the lenses are wide open, certainly considerably more detail than that achieved in our last test with the f/1.2 lenses. Contrast is also noticably improved from the level recorded with the faster lenses. It is noted that this is a challenging test target (not particularly high contrast) and that this crop reflects an area of less than 1mm square on the original negative. At the screen resolution above (at standard 72dpi) the equivalent print size would be 6 feet by 9 feet. Given this the performance wide open of both of these lenses is very impressive.

Based upon my review of the images from which these crops were taken I conclude that at f/1.4 the 50mm MC is noticably sharper than the MD in the centre, but that the gap between the lenses has narrowed at the corners and both are very similar at this point. Corner performance is actually very impressive, and contrast remains good, despite light falloff (discussed later).

It is my opinion, based upon the above results, that both lenses are fully useable even for work requiring relatively fine detail at f/1.4. This is an outstanding result and a tribute to the quality of the 30 year old design.

The shot below was taken with the 50mm f/1.4 MC Rokkor-PG at f/1.4 in order to minimise the depth of field. The bokeh exhibited in this shot is gorgeous, and it is quite probably my favourite shot taken in 2004.

At f/2 the MD lens has improved markedly to catch up to and even possibly surpass the MC version. The MC lens has naturally also improved, and in fact both lenses deliver excellent resolution at f/2. The double lines of some of the highways are visible in the crops from both lenses, but possibly slightly more clearly in the MD version.. When you consider that these lines are approximately 0.5mm apart on the original poster that is a quite incredible result.

The corner sharpness of the two lenses appears to be very similar at f/2. Overall, I feel that at f/2 the MD lens has very fractionally outperformed the MC lens, but the difference between the two lenses is very difficult to pick even at a 100% crop at 5400 dpi. Certainly there would be no way to split the two lenses based upon prints, even with very big enlargements.

At f/8 the 50mm f/1.4 MC Rokkor-PG has caught up to and possibly marginally surpassed the 50mm f/1.4 MD Rokkor-X in terms of centre resolution. Both lenses record excellent corner sharpness. This is the best aperture tested in terms of sharpness for both lenses, but the difference between the results at f/4 and f/8 is very small. Certainly either of these lenses could be used for images where critical sharpness was a priority from f/4 and above.

To test each lens in their rendition of bokeh I set up a challenging target with lots of distracting highlights in the rear. Note, this is an extreme bokeh test! The lenses were tested wide open at f/1.4, and again at f/4, what I would consider to be a normal portrait aperture when photographing in daylight.

In terms of bokeh both lenses do a good job, but not up to the level of the 58mm f/1.2 tested previously. This is to be expected given its faster aperture and longer focal length both work together to increase background separation. A cursory comparison to the 50mm f/1.2 MD Rokkor-X shows both lenses exhibit similar bokeh to that lens, however close up review of the highlights does show a very slight brighter band around the extremity of each out of focus highlight. A closeup of the individual highlights is shown below:

Both lenses show some evidence of this ring, but clearly the 50mm f/1.4 MD Rokkor-X has slightly better performance in this respect. It should be noted that the test above is an extreme one with literally hundreds of highlight spots, and huge transitions in contrast. Normal use would see a much nicer blur.

At f/4 the area out of focus is of course better defined, and you might expect that the bokeh rendition of the lenses will be much closer. Let's examine the shots and see.

The hexagon shapes of the MC's highlights are slightly more defined, but the blur is still very nice.

Bokeh Summary

One of the issues when shooting with faster lenses is the natural light falloff that occures at the extremities of the frame when shooting at, or close to wide open. Most visible when taking photos of regularly toned subjects, like landscapes with blue skies or light coloured walls etc, it manifests as a darkening of the frame at the corners.

If you shoot with negative film this may not be an issue for you, as it can often be addressed in the printing process. However with slide film a drop of a stop or so in the corners may cause them to be irretrievably darkened, and can ruin a good slide.

Virtually all lenses exhibit a degree of light falloff at wide apertures, and the real sign of a lens that handles this well is when this falloff is gone after closing down a stop or two. Lets see how the two Minolta 50mm f/1.4 lenses handle falloff.

Methodology for this test is as follows. The test target includes an area of white at both the centre and the extreme top left corner. The centre area is selected and adjusted in photoshop to be the white point for the image. A crop is taken from this area, together with a crop from the corner, and the resulting crops are desaturated, and placed side by side below.

The image to the right shows two sets of crops. The top two are from the 50mm MD at f/1.4, the bottom two from the 50mm MC at f/1.4.

As can be seen, both lenses exhibit significant falloff at f/1.4 when using slide film. As discussed above, this falloff will be less noticeable, but still apparent when using negative film. When seen side by side the falloff seems particularly significant, but when seen in terms of the full image it is lessened to a degree by the distance between the crops. For example, refer to the crop below of the full image from the 58mm f/1.4.

At f/4 the falloff is virtually eliminated on both lenses, and would not be noticed when shooting a broad expanse of a solid colour, even on slide film. Refer to the image below showing the sample area at f/4, and it can be clearly seen that for all intents and purposes falloff is eliminated at f/4.

The two 50mm f/1.4 lenses tested are outstanding optics, and performed brilliantly for what are still very fast lenses. Central and corner sharpness were outstanding from both lenses, and perfectly usable for full frame critical sharpness applications from f/4. For portraiture and general use these lenses can be used wide open at f/1.4 without hesitation, bearing in mind of course the light falloff that is evident at larger apertures.

The performance of both lenses was superior wide open than that recorded by the f/1.2 lenses at f/2, and in fact across the board, at all apertures the f/1.4 lenses outperformed the f/1.2 lenses in terms of resolution and contrast.

In terms of bokeh the 50mm f/1.4 MD Rokkor-X performed marginally better in our tests, but I would question whether anyone would be able to pick the difference in a photograph, even at larger print sizes. In general use both lenses produce a lovely blurred out of focus rendition, enabling the photographer to concentrate the viewer's attention on his subject.

Overall I rate the 50mm f/1.4 MC Rokkor-PG and the 50mm f/1.4 MD Rokkor-X as equally as good as each other. The MC had a very slight resolution advantage at f/1.4 in our test, and the MD had very slightly better bokeh in our examination of this aspect of lens performance. These differences are, however, so minor that they could simply reflect sample variation, and accordingly I would consider that the owner of either of these lenses has every reason to be pleased, and no reason to covet the other version.

A useful test would have been to also consider the 58mm f/1.4 MC Rokkor. Produced prior to April 1973, the 58mm f/1.4 has an avid following who swear by its performance. It is made from six elements in 5 groups (similar to the later 50mm f/1.7 lenses). I find it difficult to imagine that its resolution would be up to that of the later 50mms, and certainly it strikes me that Minolta would have been unlikely to produce a more expensive 7 element design to replace it unless this also brought with it improved performance.

Well there it is, my review of the f/1.4 normal lenses. Still to come are the reviews of the slower normal lenses, comprising the 50mm f/1.7, f/2 and the 45mm f/2. I am intrigued to discover if there will be a hidden gem amongst these cheap lenses.