The Ultimate Normal Lens Challenge
Minolta's most common lenses compared
The lenses being tested in the "Ultimate Normal Lens Challenge" all lined up side by side.

Back in the glory days of the Minolta manual focus system, cameras were normally sold with a 'normal' focal length lens as the standard lens to come with the body. These weren't the poor quality standard zooms that often come packaged with today's cameras, but high quality, single focal length lenses, of between 45mm and 58mm depending upon era and budget.

Many of the questions asked by owners of manual focus equipment relate to these lenses, and include such questions as "What difference is there between the 50mm MD and MC lenses?", "Is the 50mm f/1.2 better than the 58mm f/1.2?", "Will the 50mm f/1.4 be sharper than my 50mm f/1.7?" and innumerable variations upon these themes.

While there are numerous posts in various discussion groups answering these questions and many more, to the best of my knowledge until now no-one has published on the web a comprehensive test of the lenses side by side. Now you, the user, will have the chance to judge for yourself between them.

The lenses tested comprised examples of most of the normal lenses most commonly available, and my thanks go to Bob Flegg and Robert Hoehne for their provision of several of the test lenses for the comparison. The lenses tested were:

45mm f/2 MD

50mm f/2 MD

50mm f/1.7

50mm f/1.4 MD

50mm f/1.4 MC Rokkor

50mm f/1.2 MD Rokkor-X

58mm f/1.2 MC Rokkor

In order to compare all of the lenses we will be assessing them in class groups, and then comparing the best lens from each class to find the ultimate winner of all of the lenses. The first lenses examined will be the super-fast lenses, the 50mm f/1.2 MD Rokkor-X and the 58mm f/1.2 MS Rokkor-PG.

An important consideration to remember with these tests is that they should be treated as a guide only, and a general source of information. This is because only one sample of each lens was tested in this review, and there is no way for me to tell if the sample tested was indicative of the average performance of the entire production run. Your 50mm may perform better or worse than the ones shown here, so if this is important to you, you should consider testing your lens yourself to ensure ultimate sharpness.

All tests were performed on a focus calibrated X-570, using a viewfinder magnifier and a tripod, and Fuji Velvia 100F fine grained slide film. The camera's self timer was used to combat vibration. Slides taken have been scanned at 5400dpi, and focus has been individually set for each crop so as to avoid any issues with film flatness. Digital ICE and grain management has been turned off to obtain maximum possible resolution.


50mm f/1.2 MD Rokkor-X


58mm f/1.2 MC Rokkor-PG

The resolution target used in the test - sure it's not the most interesting subject, but I find it a handy subject to enable close comparisons. The red boxes indicate the crops used in the testing

The 50mm f/1.2 MD Rokkor-X and the 58mm f/1.2 MC Rokkor are the two big guns of the Minolta normal lens line up. Expensive and heavy, they have a reputation for being great performers in low light as well as being sharp and contrasty for general photography. Certainly the viewfinder image is a joy to behold when using one of these lenses. However how will they perform in the Ultimate Normal Lens Challenge?

You may have already seen my initial head to head test of these lenses conducted some time ago. In that test they performed effectively on a par against each other, but it was a very basic test, and conducted at a distance of only about 3 feet with files scanned at 2200 dpi. This test has been conducted at a greater distance, more in line with the types of distance that would commonly be used for portraiture or general photography. Additionally, my testing methods have been enhanced since that first test, with images scanned at 5400 dpi, and a more consistent test subject. Additionally, the bokeh and light fall-off of the lenses will be tested, so you can judge for yourself the results in this respect.

Resolution Tests

Above we can see the performance of the two lenses from centre and corner crops at f/1.2. Results show relatively poor detail with both lenses, and poor contrast. It should be noted however 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.

Based upon my review of the images from which these crops were taken I conclude that at f/1.2 the 50mm is just the tiniest fraction sharper than the 58mm, but really, it's like comparing the sharpness of two kitchen spoons - sure, one might have a slightly sharper edge than the other, but you wouldn't want to have to peel vegetables with it.

The loss in contrast evident above is not immediately apparent in general photography, and in fact at reasonable enlargement sizes both lenses do deliver sound results wide open - just don't expect pin-sharp 16' x 24' prints.

However it is obvious that with both lenses at f/1.2 the resolution is unsatisfactory for high detail reproduction, as would be expected. At this aperture the lenses are designed to be used in extremely low light, enabling the photographer to achieve a result that would be otherwise unattainable. In fact with 3200 speed film and shooting wide open with the 50mm f/1.2 I have taken photos handheld that were virtually in the dark.

The shot below is an example of what can be achieved at f/1.2 with the 50mm f/1.2 MD Rokkor-X. While not bitingly sharp the shot is one of my favourites.

With a 50mm f/1.2 there's not such a huge benefit in sharpness anyway, as any normal subject will exhibit a degree of softness at f/1.2 simply due to the shallow depth of field. However, with this shot the focus is perfect right on my dog's eyes, and the result looks great printed. Note the light falloff in the corners - we will examine this aspect of optical performance later.
The lens is good enough to pick up individual hairs in a low light portrait, and in fact the slightly soft result often is quite flattering when shooting portraits, as it tends to provide a smooth feel to the skin etc. In conclusion, the results achieveable at f/1.2, while softer than I might prefer, are very useable for general photography, particularly in low light circumstances, or where using a wide aperture for a specific result in terms of background/foreground blur etc. At f/1.2 I don't consider there to be a marked difference in resolution between the lenses.

At f/2 the story is quite different. While both lenses have performed considerably better than at f/1.2, the later model MD lens appears to have pulled away from the 58mm in terms of both contrast and resolution. If you look closely in the centre crop you can actually see the double line of some of the highways. 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 50mm also appears to be slightly better than the 58mm, with superior contrast as well. I feel comfortable saying that in terms of resolving power the 50mm outperforms the 58mm by a comfortable margin at f/2.

At f/4 the 58mm has improved significantly, but still sits slightly behind the 50mm in terms of resolution and contrast. Both lenses record good corner sharpness.

At f/8 the both lenses are performing very well, and at this level they both would be comfortably resolving well over 50 lppm. This is the best aperture tested in terms of sharpness for both lenses, but the 50mm is still clearly a superior performer when compared to the 58mm. Both lenses record excellent corner sharpness.

Resolution Summary

Based upon the crops above and my reviews of the full images I conclude that of the two lenses tested the 50mm demonstrated superior performance in terms of resolution at all f stops. However, I note that both lenses performed well, and remind the reader that with sample variation the same may not be true for all lenses of each type.

Resolution isn't everything in optics, and one of the reasons that many people choose one of these lenses is in fact for the great potential for a blurred background. The appearance of this background is called bokeh, and it is one of the real intangibles that can make a lens great.

Lens Bokeh

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/1.2, and again at f/4, what I would consider to be a normal portrait aperture when photographing in daylight.

The 50mm shows neutral bokeh and the areas without sharp highlights do show a very nice blur.
The 58mm demonstrates better bokeh with a lovely creamy feel.

In terms of bokeh the 50mm does do a good job. The test above is an extreme one with literally hundreds of highlight spots, and normal use would see a much nicer blur. The lens exhibits neutral bokeh, that is, the individual highlights are rendered as an even disc of light, but in this test there is no doubt that the 58mm is clearly superior, showing that creamy out of focus texture that it is famous for, despite the bright highlights in the background. A closeup of the individual highlights is shown below:

The background blur of the 50mm is not bad, it's just not outstanding.
The 58mm shows amazing bokeh.

The performance of the 58mm in this respect may partly be due to the reduced depth of field caused by its longer focal length, but that is only a small part of the reason. What this lens loses from the 50mm in terms of resolution it makes up with this outstanding out-of-focus rendition.

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.

50mm f/1.2 Rokkor-X
58mm f/1.2 Rokkor-PG

The bokeh of both lenses appears good, but the 58mm still definitely has an advantage. This is more obvious on closer inspection. The 58mm has an eight bladed diaphram, as opposed to the six blades of the 50mm. This means that at intermediate apertures such as f/4 the 58mm retains a much more rounded out of focus highlight, unlike the 50mm where the highlights are now obviously six sided.

The background blur of the 50mm shows six sided highlights at f/4.

The 58mm retains highlights that are near round.


Bokeh Summary


The images above demonstrate clearly that while the 50mm has good bokeh, it does not inherit the 'magic' bokeh of the 58mm f/1.2, which for nearly 40 years has mesmerised photographers. The images above are designed to show flaws, they don't do justice to the rich creamy bokeh that this lens produces when used. If this is your goal, the 58mm is probably the lens for you.

Light Falloff

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 ultrafast Minolta primes 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 58mm at f/1.2, the bottom two from the 50mm at f/1.2.

As can be seen, both lenses exhibit significant falloff at f/1.2 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/1.2.

At f/2 both lenses record a significant improvement in falloff. At this level the falloff would likely be not noticeable in a photograph unless the shot included a significant expanse of solid colour, such as a blue sky. The performance of the 50mm f/1.2 is marginally better than the 58mm, but the difference is not significant.

At f/4 the falloff is virtually eliminated on both lenses. The level apparent on the 50mm f/1.2 is negligible, and would not even be noticed when shooting a broad expanse of a solid colour. The falloff recorded bythe 58mm is slightly higher, but also would be effectively invisible in any print. To see the evidence of this, refer the crop below, again from the 58mm, but at f/4.

As is evident above, the slight difference in the white crops seen when they are side by side is simply not visible when looking at a full image taken at f/4.
Falloff Summary
Both lenses record significant falloff at f/1.2 that would be apparent on prints or slides. By f/2 this falloff has been significantly reduced, and by f/4 it is all but gone. Based upon the results detailed above I can conclude that the 50mm f/1.2 performs marginally better in terms of falloff, but that this difference is negligible.

The two f/1.2 normal lens designs produced by Minolta, while each a very nice lens, perform quite differently. Based upon the above, I feel that they best fit two different roles.

The 58mm f/1.2 is not as sharp as the 50mm f/1.2, but exhibits the best bokeh of the two lenses. I feel that if you a seeking a fast normal lens primarily for portraiture then the 58mm f/1.2 is the best choice. The smooth buttery bokeh together with a very slightly softer image will enable lovely portraits, and the extra 8mm of focal length will also help to compress features for a more flattering image.

If, on the other hand you are looking for a gerneral purpose super-fast normal lens then the 50mm f/1.2 Rokkor-X appears the best choice. For travel and landscape photography the higher resolution and lower falloff will be beneficial, and the wider field of view adds flexibility. However, whichever you choose to purchase you will be buying a lens of the highest quality, and which I guarantee you will enjoy using. Until you have shot with a lens of f/1.4 or faster you simply won't appreciate how great it is to have a super-bright viewfinder image that snaps into focus, making manual focusing a breeze even in really low light.

Now just to show where the super-fast normal lenses truly excel, here are a couple of shots from my first night in New York that didn't make it to the American Journey travel journal. This bar was so dark that even I could have met a girl, and yet the 50mm f/1.2 was easy to focus, and still hand-holdable.

Brian Charette, Organ.
Scott Sharrard, Guitar.
Minolta XD11 with 50mm f/1.2 MD Rokkor-X Film: Kodak TMax P3200.
Well there it is, my review of the super-fast normal lenses. Still to come are the reviews of the 50mm f/1.4s and the slower 50s. The review of these lenses will be conducted in an identical manner, and will be uploaded over the next week or so. I trust that you have enjoyed this review, and will come back soon to see the rest of the testing results.
To page 2 - the 50mm f/1.4's
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