Tripp, Trapp, Trull: Legacy Lens Guessing Game

UnderDriven said:

I did some tests of the Minolta 50mm, 85mm, Vivitar 135mm, and Panasonic 14-45mm (at 45mm) at the minimum focus distance. I should put the shots online but my summation is that the lenses need to be stopped down to at least f4, with f5.6-f8 being a bit better. The 135mm was the sharpest and had good color rendition (it was called a "close focus" lens so it was probably optimzed for that). The 14-45mm (at 45mm) was second best (actually pretty close), and the 50mm and 85mm were not as sharp.

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Yes, it is no surprise that the Vivitar 135/2.3 (which is "of course" a Komine too ;-)), wins out at close range. Just like my 28/2, it is a floating elements design specifically aimed at correcting the problems that would otherwise arise at close focus. Here's a link to a page that includes a rather informative ad for it from the time it was introduced (mid 70s or so):

http://forum.mflenses.com/early-vivitar-series-1-advertisments-t22871,start,15.html

I'd still be a bit surprised though, if the 50 and 85, even if inferior to the 135, did not manage quite well at their minimum focusing distance, particularly since they do not focus all that close for their focal length (1:7 or 1:8) and share a design type (double-gauss) not particularly troubled by differences in focusing distance. My guess is that if you had tried the 14-45 at its shortest rather than longest focal length, it might have ended up last, at least if all lenses were tried at the same aperture.

UnderDriven said:

I also did a quick test of the 85mm, 135mm, and 300mm at infinity focus. The 85mm was the clear winner with great contrast and sharpness. From that I was assuming that the 85mm was not optimized for the extreme near end of the focus range which would make sense as it is a portrait lens. I should test the 85mm at 2m to see how it performs there...

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Glad to hear that the 85 did so well at longer range and I am sure it isn't optimized to do its best at the extreme near end. However, it would not surprise me if it was optimized for about two meters, which is where it would normally be used for portraits (on an FF camera).

UnderDriven said:

I guess I am wondering if legacy lenses tended to be optimized for certain parts of the focus range, since they did not have the computer-based optical design programs available today...

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Yes, they most certainly were optmized for certain distances, usually far distances. But I am not sure that even today's prime lenses (let alone zooms) are much better in this regard even though most are internal focus and thus by implication floating-element, designs. While there are more and better ways to optimize these days, there are also new considerations/restrictions like IF (no expansion of front elements), AF, and (sometimes) IS.

Finally, I'd be interested to know your thoughts about the 50/1.4. Although I already have the 50/1.7, I am thinking about getting the 50/1.4 too since it is not much bigger or heavier, still quite inexpensive, reportedly quite a bit better optically (especially at wider apertures), and would allow me to shoot at a bit stopped down (at f2) without hazzle (the 50/1.7 doesn't have a click stop between 1.7 and 2.8). As you might already know, there are four different versions of the MC/MD 50/1.4: The MC and the first MD, both with 55 mm filter diameter and the same optical design (5 groups, 7 elements), and the two last MDs, both with 49 mm filter diameter and another optical design (6 groups, 7 elements). Somewhat surprisingly, the first design enjoys a stronger reputation among the specialists than the second, although I am not sure of how much a performance difference there really is. So which one have you got and what do you think about it?

Anders W said:

Hmm. At least the middle three of the lenses you already own (50, 85, 135) have an enviable reputation and I seriously doubt that even current Zeiss or Voigtländer lenses would be more than marginally better (if at all). Although I certainly wouldn't deny the merits of current lens technology, these three all belong to a category of lenses where not a whole lot has happened since they were designed. They are all relatively simple constructions, essentially double-gauss with six or seven elements, which also means that the number of lens surfaces is hardly a serious problem for the lens coating technique of the time.

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You may be correct that the fundamental designs have not changed for quite a while. However, did Minolta use the absolute best glass for these lenses? What was the tolerance for figuring the glass? Was it as good as a Leica that cost much more? Was Minolta's multicoating as good as Zeiss' T* or Nikon's Nano Crystal Coating? I think the Minolta lenses are good, but I see something in Leica and Zeiss lenses that looks better to my eye. Voigtlander may not be up on the top tier, but I think their lenses are close and more reasonably priced...

Anders W said:

When it comes to coatings, my general impression (which doesn't aspire to be more than just an impression) is that major steps forward were taken up to about 1980 but that later developments make less of a difference, not because there is no progress but because what had already been achieved was already close to the physical limit.

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I think Nikon's Nano Crystal Coating is more recent and is supposedly very good. One thing that can be a problem with digital cameras is light reflected off the sensor which lowers contrast (it reflects off the sensor, onto the rear element, and back onto the sensor again). One thing Sigma did when they refreshed their lenses for digital was to add a coating to the rear element to suppress this reflected light. Whether this is a problem with all pre-digital lenses I don't know, but it is an issue for some...

Anders W said:

Not sure I follow you here. Do you mean that it would be more difficult to focus with Contax lenses than with other MF lenses? And if so, why?

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Contax G lenses are autofocus only so the only way to focus them is to turn the AF screw on the lens. The Contax G adapters do this, at first with a small wheel and later with a large ring (like a normal focus ring) that turns the screw. Although this does work, I am skeptical that it provides the smooth precise focusing action of legacy manual focus lenses (especially the original small wheel adapters).

The other thing is that the bokeh of the 45mm seems a bit nervous to me in the images I have seen online. Another thing about the Leica lenses is that the bokeh is usually very good...

Anders W said:

Yes, I have thought of getting a legacy macro too, perhaps even bellows and a focusing rail (which, in contrast to an ordinary macro lens, is something I never had even in the film days). It would be fun to play with and legacy macros also belong among the lens types that I think are still going strong. I guess the cost would stay reasonable even if I wouldn't use it all that much.

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The 80mm I bought is a bellows lens, but it can also be used on the Auto Tube as well. I wanted to do some work at 1:1 with the G1, and based on my research I determined that getting a lens which was designed for 1:1 was better than getting a normal macro lens that could go from infinity to 1:1. However, after getting it I did a comparison with my Sigma 150mm macro (on my Sigma SD14) and they were very close at 1:1. So perhaps I could have just bought a normal macro and saved some money...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

You may be correct that the fundamental designs have not changed for quite a while. However, did Minolta use the absolute best glass for these lenses? What was the tolerance for figuring the glass? Was it as good as a Leica that cost much more? Was Minolta's multicoating as good as Zeiss' T* or Nikon's Nano Crystal Coating? I think the Minolta lenses are good, but I see something in Leica and Zeiss lenses that looks better to my eye. Voigtlander may not be up on the top tier, but I think their lenses are close and more reasonably priced...

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Hmm. I don't know enough about the detail to really argue with that. But FWIW I stumbled on a Chinese page the other day, with test results for a number of 50 mm lenses of relatively recent origin but also including the Minolta MD 50/1.4 and MD 50/1.7. And as far as I can see, at least the first of the two can stand a comparison with the Summilux as well as the Summicron: ;-)

http://www3.xitek.com/papers/xitek/xitek-429.htm

UnderDriven said:

I think Nikon's Nano Crystal Coating is more recent and is supposedly very good. One thing that can be a problem with digital cameras is light reflected off the sensor which lowers contrast (it reflects off the sensor, onto the rear element, and back onto the sensor again). One thing Sigma did when they refreshed their lenses for digital was to add a coating to the rear element to suppress this reflected light. Whether this is a problem with all pre-digital lenses I don't know, but it is an issue for some...

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Yes you are right that this is a difference between digital and film. While the film reflects too, it is a matte rather than shiny surface so the risk that the light bounces back onto the rear element and then back again is perhaps somewhat greater. I know that this difference between film and a digital sensor forced a redesign of flash TTL metering, where the shutter curtain is now used to measure a pre-flash rather than the film used to measure the real flash, as was originally the case.

UnderDriven said:

Contax G lenses are autofocus only so the only way to focus them is to turn the AF screw on the lens. The Contax G adapters do this, at first with a small wheel and later with a large ring (like a normal focus ring) that turns the screw. Although this does work, I am skeptical that it provides the smooth precise focusing action of legacy manual focus lenses (especially the original small wheel adapters).

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OK, then I understand. Did not know that the Contax G lenses were AF only.

UnderDriven said:

The 80mm I bought is a bellows lens, but it can also be used on the Auto Tube as well. I wanted to do some work at 1:1 with the G1, and based on my research I determined that getting a lens which was designed for 1:1 was better than getting a normal macro lens that could go from infinity to 1:1. However, after getting it I did a comparison with my Sigma 150mm macro (on my Sigma SD14) and they were very close at 1:1. So perhaps I could have just bought a normal macro and saved some money...

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Good to know. But one interesting advantage of the bellows version is the ability to tilt the lens so as to place the DOF the way you want. I suppose that this technique can even be used at non-macro distances provided that the bellows lens is up to the task, as I would guess it is even if optimized for 1:1.

BTW: Did you see the second part of my response to your previous post, where I asked some questions regarding your experiences with the Minolta 50/1.4?

Anders W said:

Hmm. I don't know enough about the detail to really argue with that. But FWIW I stumbled on a Chinese page the other day, with test results for a number of 50 mm lenses of relatively recent origin but also including the Minolta MD 50/1.4 and MD 50/1.7. And as far as I can see, at least the first of the two can stand a comparison with the Summilux as well as the Summicron: ;-)

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In terms of sharpness they may be able to compete, but there are many other qualities that are harder to measure (contrast, bokeh). On the other hand, I may be too pessimistic about the Minolta lenses...

Anders W said:

Good to know. But one interesting advantage of the bellows version is the ability to tilt the lens so as to place the DOF the way you want. I suppose that this technique can even be used at non-macro distances provided that the bellows lens is up to the task, as I would guess it is even if optimized for 1:1.

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On some bellows, yes. Contax, Minolta Auto Bellows III, and Nikon PB-4 are the ones I'm aware of in legacy bellows. Novoflex has some products as well but not cheap...

Anders W said:

BTW: Did you see the second part of my response to your previous post, where I asked some questions regarding your experiences with the Minolta 50/1.4?

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Yes, I was planning to answer that by showing some image crops. Unfortunately, I forgot that when I did the 50mm test I shot at ISO 800 because I used the camera in a low light situation the day before and I didn't check. I could tell anyway that f1.4 and f2 were soft, but I would not put those crops online. So I will have to take those shots again--probably in a day or two...

The other issue is color fringing at f1.4 and f2, less at f2.8, and gone at f4. I don't mind that so much since I tend to shoot at f4 or f5.6, but if you want to shoot at f2 then it's an issue. In any case, best to wait until I get the crops online--then you can see for yourself...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

On some bellows, yes. Contax, Minolta Auto Bellows III, and Nikon PB-4 are the ones I'm aware of in legacy bellows. Novoflex has some products as well but not cheap...

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Thanks. I should probably take a look at the Minolta bellows since I am already some way down the Minolta line. ;-)

UnderDriven said:

UnderDriven said:

BTW: Did you see the second part of my response to your previous post, where I asked some questions regarding your experiences with the Minolta 50/1.4?

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Yes, I was planning to answer that by showing some image crops. Unfortunately, I forgot that when I did the 50mm test I shot at ISO 800 because I used the camera in a low light situation the day before and I didn't check. I could tell anyway that f1.4 and f2 were soft, but I would not put those crops online. So I will have to take those shots again--probably in a day or two...

The other issue is color fringing at f1.4 and f2, less at f2.8, and gone at f4. I don't mind that so much since I tend to shoot at f4 or f5.6, but if you want to shoot at f2 then it's an issue. In any case, best to wait until I get the crops online--then you can see for yourself...

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Thanks. I would very much appreciate seeing these crops if you can find the time to do it.

As to LoCA (purple fringing/color fringing), this is something I dislike rather intensely. On the other hand, it is a drawback shared by virtually all fast lenses when used wide open or nearly wide open and the extent to which it shows up badly is very dependent on exactly what you shoot.

Although I plan to use all the legacy lenses I bought primarily at wide apertures (the Vivitar 28 possibly excepted if indeed it turns out to do pretty well at close range), I think I would rarely shoot scenes where the purple fringing would show up badly (even if it's always there if you look carefully enough).

In general, I think of these old MF lenses primarily as supplements to modern, native m43 zooms (fast 12-50 zoom when it becomes available, 7-14, 100-300) for situations when the max aperture of a zoom is insufficient (non-stationary subjects in low light or in order to maximize background blur).

Anders W said:

Thanks. I should probably take a look at the Minolta bellows since I am already some way down the Minolta line. ;-)

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Good idea, but the Auto Bellows III can be hard to find...

Anders W said:

Thanks. I would very much appreciate seeing these crops if you can find the time to do it.

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I wasn't feeling well yesterday, but I did take some shots the night before. However, I am now thinking that I need to do this more professionally. I am going to set up a new target which should allow for better comparisons...

Anders W said:

As to LoCA (purple fringing/color fringing), this is something I dislike rather intensely. On the other hand, it is a drawback shared by virtually all fast lenses when used wide open or nearly wide open and the extent to which it shows up badly is very dependent on exactly what you shoot.

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Purple fringing is different from LoCA (which is what I was referring to in my post). Purple fringing will not happen in my test setup since I don't have any super high contrast transitions. Actually, I should correct my statement about the LoCA. I see it a lot on the LCD when I am focusing wide open with the 50mm f1.4: a misfocusing in one direction makes everything go green, and in the other direction everything goes magenta. I found this disconcerting the first time I used the 50mm, but since I wanted to shoot at f4-f5.6 I stopped down and it went away. I only assumed that there would be fringing at f1.4 on the actual photos. I don't see any on my flat test target, but in a 3D situation OOF areas are likely to have some fringing. My new test target will allow that to be checked...

Anders W said:

In general, I think of these old MF lenses primarily as supplements to modern, native m43 zooms (fast 12-50 zoom when it becomes available, 7-14, 100-300) for situations when the max aperture of a zoom is insufficient (non-stationary subjects in low light or in order to maximize background blur).

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My reason for using legacy lenses is the nice focus action. Most of my shooting is on a tripod with static subjects, so I enjoy using MF lenses and the magnified LCD image to check focus. Modern zooms tend to have poor focusing action (or focus by wire) and the focus movement range is small to support fast AF. I like a smooth MF lens with a long focus range so I can be more precise. For other types of photography zooms and AF makes sense...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

Anders W wrote:
Good idea, but the Auto Bellows III can be hard to find...

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Thanks for the warning. But at it helps a lot to know exactly what I should look for. Since I was not a Minolta-person until very recently (in the film era, I used Konicas only), I had no idea what had ever been available as far as Minolta bellows are concerned.

UnderDriven said:

I wasn't feeling well yesterday, but I did take some shots the night before. However, I am now thinking that I need to do this more professionally. I am going to set up a new target which should allow for better comparisons...

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I really appreciate your willingness to help with this! But there's no big hurry so make sure you take care of yourself first of all!

UnderDriven said:

Purple fringing is different from LoCA (which is what I was referring to in my post). Purple fringing will not happen in my test setup since I don't have any super high contrast transitions.

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OK. Then I partly misunderstood what you had in mind. However, both kinds of fringing actually stem from LoCA (longitudinal chromatic aberration), although the phenomenon ordinarily referred to as "purple fringing" applies to things that are in focus whereas what you are describing refers to things that are out of focus. A lens may be well corrected for LoCA for things in focus but still show LoCA with respect to OOF areas, although I think there is usually at least some correlation between the two.

UnderDriven said:

Actually, I should correct my statement about the LoCA. I see it a lot on the LCD when I am focusing wide open with the 50mm f1.4: a misfocusing in one direction makes everything go green, and in the other direction everything goes magenta. I found this disconcerting the first time I used the 50mm, but since I wanted to shoot at f4-f5.6 I stopped down and it went away. I only assumed that there would be fringing at f1.4 on the actual photos. I don't see any on my flat test target, but in a 3D situation OOF areas are likely to have some fringing. My new test target will allow that to be checked...

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Interesting. Looking forward to your test shots.

UnderDriven said:

My reason for using legacy lenses is the nice focus action. Most of my shooting is on a tripod with static subjects, so I enjoy using MF lenses and the magnified LCD image to check focus. Modern zooms tend to have poor focusing action (or focus by wire) and the focus movement range is small to support fast AF. I like a smooth MF lens with a long focus range so I can be more precise. For other types of photography zooms and AF makes sense...

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Yes, I can certainly understand why you would appreciate a nice MF lens in that scenario, provided that you can get a nicely magnified view on the LCD or in the EVF. Live view and EVF make all the difference here. With the Pentax K100D that I am about to upgrade from, manual focus is nightmarish.

UnderDriven said:

I think Nikon's Nano Crystal Coating is more recent and is supposedly very good. One thing that can be a problem with digital cameras is light reflected off the sensor which lowers contrast (it reflects off the sensor, onto the rear element, and back onto the sensor again). One thing Sigma did when they refreshed their lenses for digital was to add a coating to the rear element to suppress this reflected light. Whether this is a problem with all pre-digital lenses I don't know, but it is an issue for some...

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Oh. I forgot to mention that, by chance (I wasn't looking for it), came across a page dealing with this topic the other day. It happens to be specifically about Minolta lenses too, although to a large extent about the adapters with correction lenses that you need in order to put Minolta MF lenses on later A-mount bodies. At any rate, I thought you might be interested so here it is:

http://thesybersite.com/minolta/sensor-reflection/

Anders W said:

Interesting. Looking forward to your test shots.

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My apologies for taking so long to get some images online. There were various distractions...

I am still working on my indoor test setup, but I did manage to do some outdoor tests last week at infinity focus. You can find the results here:

http://www.kotay.net/keith/photo/eval/panasonic-g1/110425.shtml

I have to take back my comments about the Vivitar Series 1 135mm f2.3 not performing well at infinity focus. It did much better this time, perhaps I misfocused on the previous occasion--it was a fairly ad hoc test anyway, this time I was more careful...

The performance of the Minolta MD 50mm f1.4 was disappointing, but it may well be that I have a bad sample (or it was abused before I bought it). I will test it again, though, because of the fact that the f3.3 image looks better than the f5.6 image. Perhaps I inadvertently moved the focus ring when changing aperture. On tho other hand, it wasn't great indoors either so I'm not too shocked...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

Hi Keith,

And a great many thanks for getting back on this and taking the trouble to do these test shots, and presenting them so nicely!

As I hoped and expected, the 85/2 does very well. There is some halation and some loss of contrast wide open of course (possibly exacerbated by the fact that you had to overexpose this partiular shot a little bit), but no worse than I expected, and it still looks useable at f/2 for the purposes I have in mind (which are of course quite different from your test scene).

As to the Minolta 50/1.4, I see nothing wrong with it's performance wide open and at f/2.3. Based on other tests that I have seen, it should be useable wide open and quite good when stopped down just a little bit, and to me your shots confirm that impression. I am pretty sure the shots at 3.3 and 5.6 are both off with regard to focus. My guess is that you inadvertently moved the focus ring a little bit when readjusting the aperture to 3.3, since that shot is clearly worse than any of the others. The reason it improves a bit again at 5.6 is probably due to the increased DOF.

I am glad the shots at 1.4 and 2.3 are encouraging, since I just bought the 50/1.4. It arrived from the US the day before yesterday and seems to be in good shape in every regard: cosmetically, optically, and mechanically.

BTW: I once owned the Nikkor PC 35/2.8 too (bought used in Japan in 1980), although I am not sure it was exactly the same version as the one you have (there have been quite a few versions over the years I think). At any rate, my impression of it was similar to the one revealed by your test shots. It was hardly tack sharp unless well stopped down. And if you shifted it, so that you were no longer at the center of the wide image circle, it was pretty useless wide open. Of course, that's a lens primarily meant for static subjects with the camera on a tripod, so it pretty much accomplishes what it is designed to accomplish anyway.

I am certainly looking forward to your indoor shots too, if you find the time to do them.

Anders W said:

And a great many thanks for getting back on this and taking the trouble to do these test shots, and presenting them so nicely!

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You're welcome...

Anders W said:

As I hoped and expected, the 85/2 does very well. There is some halation and some loss of contrast wide open of course (possibly exacerbated by the fact that you had to overexpose this partiular shot a little bit), but no worse than I expected, and it still looks useable at f/2 for the purposes I have in mind (which are of course quite different from your test scene).

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Yes, the 85mm is a nice lens but I will probably get a 90mm macro/close focus lens soon and then it is redundant to carry the Minolta 85mm. I should have put the ND filter on the 85mm for the f2 image but I got lazy--I should probably tweak the exposure in RAW development, but it is hard to know how much is right to compensate for the 1/3 stop overexposure. When I test the 50mm again I will reshoot the 85mm f2 image...

Anders W said:

I am pretty sure the shots at 3.3 and 5.6 are both off with regard to focus. My guess is that you inadvertently moved the focus ring a little bit when readjusting the aperture to 3.3, since that shot is clearly worse than any of the others.

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Probably, but I will test it again soon. I may as well test the Minolta MC 300mm f4.5 at the same time, just for completeness...

Anders W said:

I am glad the shots at 1.4 and 2.3 are encouraging, since I just bought the 50/1.4. It arrived from the US the day before yesterday and seems to be in good shape in every regard: cosmetically, optically, and mechanically.

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Great. I hope you like it...

Anders W said:

BTW: I once owned the Nikkor PC 35/2.8 too (bought used in Japan in 1980), although I am not sure it was exactly the same version as the one you have (there have been quite a few versions over the years I think). At any rate, my impression of it was similar to the one revealed by your test shots. It was hardly tack sharp unless well stopped down. And if you shifted it, so that you were no longer at the center of the wide image circle, it was pretty useless wide open. Of course, that's a lens primarily meant for static subjects with the camera on a tripod, so it pretty much accomplishes what it is designed to accomplish anyway.

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Mine is the last version and it is in great shape. I had hoped it would be sharper, but it is okay stopped down (not likely to ever use it wide open anyway). The nice thing about using it with a non-FF sensor is that max shift is still pretty good IQ...

Anders W said:

I am certainly looking forward to your indoor shots too, if you find the time to do them.

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I'm working on it, but I have a cold right now which is not helping. I plan to start renting some lenses soon to help decide what to buy next. I will probably rent the Voigtlander 90mm f3.5 first...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

Yes, the 85mm is a nice lens but I will probably get a 90mm macro/close focus lens soon and then it is redundant to carry the Minolta 85mm. I should have put the ND filter on the 85mm for the f2 image but I got lazy--I should probably tweak the exposure in RAW development, but it is hard to know how much is right to compensate for the 1/3 stop overexposure. When I test the 50mm again I will reshoot the 85mm f2 image...

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Not a big problem so no real need to redo this particular shot. But as to correcting in RAW development, wouldn't you RAW converter simply tell you when you have reduced by one third of a stop? Mine (Silkypix) certainly does.

One other thing here: I noted your observation and theory regarding the step from wide open to one stop down only corresponding to 2/3 stop in terms of what your meter told you. I have no reason to doubt your observation but I'd question your explanation (sensor size). My guess would rather be that the actual light transmission and the nominal f-stop are more out of line with each other at wide apertures due to vignetting (which of course is far less pronounced with an FF lens on m43 but still noticeable) and possibly other issues as well (increased loss due to reflections).

UnderDriven said:

UnderDriven said:

I am pretty sure the shots at 3.3 and 5.6 are both off with regard to focus. My guess is that you inadvertently moved the focus ring a little bit when readjusting the aperture to 3.3, since that shot is clearly worse than any of the others.

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Probably, but I will test it again soon. I may as well test the Minolta MC 300mm f4.5 at the same time, just for completeness...

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Yes, it would be nice if you redid the test of the Minolta 50/1.4 and it would be interesting to see the results for the MC 300 too. However, I am already pretty sure that your 50/1.4 is quite all right. Even if the lens were faulty, I have a very hard time imagining that its resolution would be worse at 3.3 and 5.6 than at 1.4 or 2.3 as is the case in your current series of test shots. And you do agree that both 1.4 and 2.3 look quite all right in view of what we might expect, don't you?

UnderDriven said:

I'm working on it, but I have a cold right now which is not helping. I plan to start renting some lenses soon to help decide what to buy next. I will probably rent the Voigtlander 90mm f3.5 first...

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Take care of yourself first of all and do it when you feel better and have a moment to spare. And good luck with your 90 mm macro hunting!

P.S. A few more observations regarding your test shots before I forget what I wanted to say:

First, none of the lenses show any sign of LoCA in the in-focus area (purple fringing). This may in part be because the scene you shot is not sufficiently revealing in that regard, although I would have expected to see at least some traces of it around, for example, the white window frames, if indeed any of the lenses had significant problems in this regard. How they do with regard to LoCA in the out of focus area can of course not really be judged by means of these shots.

Second, all three Minoltas appear to be very well corrected with respect to lateral CA. Although I can see traces of it in all three cases, I have to look very carefully to find them. The 85/2 shows significant CA when used with the tele converter, but that does not really count.

The other three lenses all show a bit more CA than the Minoltas to my eyes. In the case of the Panasonic, this is a bit surprising since lateral CA is supposed to be auto-corrected with Panasonic m43 lenses on m43 cameras. The Vivitar shows lateral CA of the more unusual kind (blue - yellow) and I first mistook it for longitudinal CA (purple fringing) because the background makes the blue fringe much more visible than the yellow one. All the others show the more common type of lateral CA (green - red).

As far as resolution/microcontrast is concerned, both the Minolta 50 and the Minolta 85 appear to improve very quickly when you stop down. The Minolta 85 is close to peak in the center already at 3.3 and I think we will be able to draw similar conclusions about the 50 once we have a fully correct series of test shots. From my point of view, this is particularly nice, since I plan to use them both primarily at rather wide apertures, where a zoom would be too slow. The Vivitar 135 eventually becomes just as sharp as the Minolta 50 and 85, but it does not really get there until 5.6.

Anders W said:

Not a big problem so no real need to redo this particular shot. But as to correcting in RAW development, wouldn't you RAW converter simply tell you when you have reduced by one third of a stop? Mine (Silkypix) certainly does.

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I use Bibble. I'm not sure the exposure adjustment is in stops, but maybe it is. That would make sense, but for some reason it didn't strike me that way...

Anders W said:

One other thing here: I noted your observation and theory regarding the step from wide open to one stop down only corresponding to 2/3 stop in terms of what your meter told you. I have no reason to doubt your observation but I'd question your explanation (sensor size). My guess would rather be that the actual light transmission and the nominal f-stop are more out of line with each other at wide apertures due to vignetting (which of course is far less pronounced with an FF lens on m43 but still noticeable) and possibly other issues as well (increased loss due to reflections).

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I think we are saying the same thing. For a larger sensor the vignetting would be more severe and moving from f2 to f1.4 on the 50mm would result in an average illumination over the whole sensor which would be more than the 2/3 stop I'm seeing, due to vigentting (the result being a whole stop which is what the lens indicates). On the other hand, with center weighted metering that should be of less concern given that the center has priority. In any case, if you assume a single pixel sensor on the mount axis I would think that it would be less affected by slightly reducing the aperture size. But I may be wrong...

Anders W said:

Yes, it would be nice if you redid the test of the Minolta 50/1.4 and it would be interesting to see the results for the MC 300 too. However, I am already pretty sure that your 50/1.4 is quite all right. Even if the lens were faulty, I have a very hard time imagining that its resolution would be worse at 3.3 and 5.6 than at 1.4 or 2.3 as is the case in your current series of test shots. And you do agree that both 1.4 and 2.3 look quite all right in view of what we might expect, don't you?

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Well, I have to admit that no lens is ever sharp enough for me. That is an unfortunate bias on my part, since there are many other aspects of a lens that contribute to the image. I believe I am prejudiced by some of the images I have seen by Ansel Adams (at museum exhibitions) that are almost unbelievably detailed. While it is silly to expect a 4/3 sensor (or even a FF sensor) to ever be able to compete with an 8x10 negative for a given enlargement size, I still want sharper images. Actually, Ansel Adams' lenses were probably inferior to some of the small format lenses we have today, but that huge negative allows for a lot of optical imperfections...

I am also a bit spoiled by my Sigma SD14 and the Sigma 150mm f2.8 macro. The SD14 has no AA filter, and the 150mm macro is a very sharp lens. Together, they have produced some very sharp images--unfortunately the SD14 is only a 4.7MP camera spatially, so enlargements are limited. The G1 has a very light AA filter, which is one of the reasons I was attracted to it. However, when I bought it I told myself that I was going to use my old Minolta lenses and not care about sharpness; an attempt to cure myself of my sharpness "hangup." Now I want sharper lenses so the cure has failed...

Anders W said:

Take care of yourself first of all and do it when you feel better and have a moment to spare. And good luck with your 90 mm macro hunting!

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Thanks.

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

Anders W said:

The other three lenses all show a bit more CA than the Minoltas to my eyes. In the case of the Panasonic, this is a bit surprising since lateral CA is supposed to be auto-corrected with Panasonic m43 lenses on m43 cameras. The Vivitar shows lateral CA of the more unusual kind (blue - yellow) and I first mistook it for longitudinal CA (purple fringing) because the background makes the blue fringe much more visible than the yellow one. All the others show the more common type of lateral CA (green - red).

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I think the supplied RAW software will automatically correct for CA, but I don't think Bibble does...

It is interesting that you tend to be more aware of CA than I am. I can surely see it on the 85mm + 2x shots, but I don't notice it elsewhere. I am glad, since that means there is at least one lens parameter I do not obsess over...

However, now that you mention it, I do see it in the edge shots of the Nikon 35mm (cyan in the windows), a bit in the Panasonic edge shots (cyan in the windows), and a hint of yellow in the Vivitar in the wall-sky transition. However, I have to take off my glasses and get very close to the monitor to notice it, so I suppose my glasses plus my normal viewing distance tends to make it more difficult for me to see...

Anders W said:

As far as resolution/microcontrast is concerned, both the Minolta 50 and the Minolta 85 appear to improve very quickly when you stop down. The Minolta 85 is close to peak in the center already at 3.3 and I think we will be able to draw similar conclusions about the 50 once we have a fully correct series of test shots. From my point of view, this is particularly nice, since I plan to use them both primarily at rather wide apertures, where a zoom would be too slow. The Vivitar 135 eventually becomes just as sharp as the Minolta 50 and 85, but it does not really get there until 5.6.

Click to expand...

I was outbid on a Contax G adapter on eBay a couple of weeks ago, but I may have to pay the full price just to test my 45mm. That lens has the highest MTF rating on photodo.com (4.7) so I might like it very much. However, before I do that I will probably buy an Olympus 50mm f3.5 macro and see if it is sharp enough for me (at $99 it is a bargain--less than the Contax G adapter). I like macro lenses, but I can tolerate slow MF lenses because I usually work with a tripod. In your case, it is a different situation since you want to use large apertures. I will probably also rent a Zeiss 100mm macro just to see how sharp it is (as an upper bound), but I don't think I would ever pay $1800 for a lens...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

I think we are saying the same thing. For a larger sensor the vignetting would be more severe and moving from f2 to f1.4 on the 50mm would result in an average illumination over the whole sensor which would be more than the 2/3 stop I'm seeing, due to vigentting (the result being a whole stop which is what the lens indicates). On the other hand, with center weighted metering that should be of less concern given that the center has priority. In any case, if you assume a single pixel sensor on the mount axis I would think that it would be less affected by slightly reducing the aperture size. But I may be wrong...

Click to expand...

Yes. Perhaps I misunderstood you slightly. We are probably more in agreement here than I thought. If you used center-weighted metering, then vignetting should be even less of an issue than it already is because of the reduced sensor size. And yes, a single-pixel sensor at dead-center would practically eliminate the possibility that the light loss could be ascribed to vignetting. However, there might be additional reasons why f-stops (nominal) and t-stops (real) get increasingly out of line with each other at very large apertures.

UnderDriven said:

Well, I have to admit that no lens is ever sharp enough for me. That is an unfortunate bias on my part, since there are many other aspects of a lens that contribute to the image. I believe I am prejudiced by some of the images I have seen by Ansel Adams (at museum exhibitions) that are almost unbelievably detailed. While it is silly to expect a 4/3 sensor (or even a FF sensor) to ever be able to compete with an 8x10 negative for a given enlargement size, I still want sharper images. Actually, Ansel Adams' lenses were probably inferior to some of the small format lenses we have today, but that huge negative allows for a lot of optical imperfections...

Click to expand...

I have never seen any of Ansel Adams original prints unfortunately. Or perhaps I should be glad, since I worry less about the fact that we still cannot accomplish what he did. ;-) At any rate, I am pretty sure that even a paltry m43 sensors can now produce better results than we managed with 35 mm film.

UnderDriven said:

I am also a bit spoiled by my Sigma SD14 and the Sigma 150mm f2.8 macro. The SD14 has no AA filter, and the 150mm macro is a very sharp lens. Together, they have produced some very sharp images--unfortunately the SD14 is only a 4.7MP camera spatially, so enlargements are limited. The G1 has a very light AA filter, which is one of the reasons I was attracted to it. However, when I bought it I told myself that I was going to use my old Minolta lenses and not care about sharpness; an attempt to cure myself of my sharpness "hangup." Now I want sharper lenses so the cure has failed...

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Aha. So you have an SD14 too. Interesting. I hope that a Foveonlike sensor (i.e., one with RGB-pixels) will eventually be the dominant technique for all digital cameras. I am still waiting with a bit of curiousity for the SD1 that is supposed to be around the corner. What you could do right now if you want a little more resolution is of course to upgrade to the GH2, which at least will give you a bit more resolution on account of the increased pixel density as well as the multi-aspect sensor.

As to the Minoltas we are talking about, I certainly do not think they have anything to be ashamed of when it comes to resolution. OK, they are not macro lenses, and if you are looking for something that will be entirely satisfactory in close-up work, a real macro is of course a better bet. But for other things, I am pretty sure that the Minoltas, when stopped down to peak aperture, delivers something very close to what we can hope for given limitations of the sensor.

In fact, when I looked at your test shots a second time, I was surprised at how well the 50/1.4 is doing wide open, especially at the edge. OK. There is a clear loss of contrast, including microcontrast. But there's hardly any sign of blur. Pretty much all the details are there already at 1.4, just rendered with less contrast and thus less readily visible.

UnderDriven said:

I think the supplied RAW software will automatically correct for CA, but I don't think Bibble does...

Click to expand...

OK. That explains it.

UnderDriven said:

It is interesting that you tend to be more aware of CA than I am. I can surely see it on the 85mm + 2x shots, but I don't notice it elsewhere. I am glad, since that means there is at least one lens parameter I do not obsess over...

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I am not really obsessed by it either. ;-) I looked for it in this case more out of sheer curiousity than anything else. The only case where I saw it without looking for it was the 85 with TC. And lateral CA is so easily corrected if you want, so it's one of the last things I really worry about.

UnderDriven said:

However, now that you mention it, I do see it in the edge shots of the Nikon 35mm (cyan in the windows), a bit in the Panasonic edge shots (cyan in the windows), and a hint of yellow in the Vivitar in the wall-sky transition.

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Yes, that's where I spotted it too. In addition, take a look at the window frames in the Vivitar shots and you'll see the yellow and blue fringes, with the yellow one being very difficult to see until the lens is well stopped down so that the fringe is really sharp.

UnderDriven said:

However, I have to take off my glasses and get very close to the monitor to notice it, so I suppose my glasses plus my normal viewing distance tends to make it more difficult for me to see...

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That's what I do too (taking off my glasses or looking above rather than through them). And I am very near-sighted on my (otherwise) best eye (more than -8 diopters) so I can get very close, almost hitting the monitor with my nose. How's that for pixel peeping? ;-)

Anders W said:

I am not really obsessed by it either. ;-) I looked for it in this case more out of sheer curiousity than anything else. The only case where I saw it without looking for it was the 85 with TC. And lateral CA is so easily corrected if you want, so it's one of the last things I really worry about.

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My apologies, I wasn't implying that you were 'obsessed', just that it is something you notice (or look for). I was only using the word 'obsessed' to apply to myself...

Anders W said:

Yes, that's where I spotted it too. In addition, take a look at the window frames in the Vivitar shots and you'll see the yellow and blue fringes, with the yellow one being very difficult to see until the lens is well stopped down so that the fringe is really sharp.

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I would never notice it normally...

Anders W said:

That's what I do too (taking off my glasses or looking above rather than through them). And I am very near-sighted on my (otherwise) best eye (more than -8 diopters) so I can get very close, almost hitting the monitor with my nose. How's that for pixel peeping? ;-)

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Yes, I also look over my glasses often, but not normally when I am working on the computer. However, I will have to get new glasses with a weaker prescription since I must move the lenses away from my eyes to truly judge sharpness (often my glasses are on the end of my nose). I have the same problem when reading, so it's time for 'reading glasses'. Unfortunately, the eyes seem to go first as people age, which is even more sad for a photographer...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml

UnderDriven said:

My apologies, I wasn't implying that you were 'obsessed', just that it is something you notice (or look for). I was only using the word 'obsessed' to apply to myself...

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Absolutely no problem. I was in no way offended or upset.

UnderDriven said:

Yes, I also look over my glasses often, but not normally when I am working on the computer. However, I will have to get new glasses with a weaker prescription since I must move the lenses away from my eyes to truly judge sharpness (often my glasses are on the end of my nose). I have the same problem when reading, so it's time for 'reading glasses'. Unfortunately, the eyes seem to go first as people age, which is even more sad for a photographer...

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Yes we are all getting there. The computer is still fine with me too. But reading in low light starts to be a problem. No way to crank up the ISO, I am afraid ... ;-)

BTW: Which of the Minolta MD 50/1.4 versions is it that you have? My guess is that it is the same as mine, i.e., the last (third) version, with a 49 mm filter thread and without the "Rokkor" designation on the front ring. Am I right? If so, which serial number do you have? It might help me date my copy. Mine has no. 8031571, which I would guess is a rather early in the series. Probably not younger than 1985 but probably not older than 1983, since it has the index pin introduced with the Minolta X-600 in 1983.

Anders W said:

Yes. Perhaps I misunderstood you slightly. We are probably more in agreement here than I thought. If you used center-weighted metering, then vignetting should be even less of an issue than it already is because of the reduced sensor size. And yes, a single-pixel sensor at dead-center would practically eliminate the possibility that the light loss could be ascribed to vignetting. However, there might be additional reasons why f-stops (nominal) and t-stops (real) get increasingly out of line with each other at very large apertures.

Click to expand...

Agreed...

Anders W said:

I have never seen any of Ansel Adams original prints unfortunately. Or perhaps I should be glad, since I worry less about the fact that we still cannot accomplish what he did. ;-) At any rate, I am pretty sure that even a paltry m43 sensors can now produce better results than we managed with 35 mm film.

Click to expand...

I suppose that is true and, in fact, it was one of the justifications for Olympus when developing the 4/3 format (the 4/3 format was considered sufficient since the expectation was that it would be able to rival the IQ of 35mm film). In some ways (and in hindsight) that is a questionable argument, since Olympus (and now Panasonic) are no longer competing with 35mm film--they are competing with other digital sensors which are larger and can therefore produce better results in some aspects of image quality (dynamic range, noise, etc.)...

Anders W said:

Aha. So you have an SD14 too. Interesting. I hope that a Foveonlike sensor (i.e., one with RGB-pixels) will eventually be the dominant technique for all digital cameras. I am still waiting with a bit of curiousity for the SD1 that is supposed to be around the corner. What you could do right now if you want a little more resolution is of course to upgrade to the GH2, which at least will give you a bit more resolution on account of the increased pixel density as well as the multi-aspect sensor.

Click to expand...

There are major technical issues with the Foveon sensor, mostly related to color accuracy. The layered sensor cannot respond to R, G, and B exactly because of the absorbtion characteristics of silicon. Therefore, a complex reconstruction of RGB is required from the data--this leads to color inaccuracy (the cyan sky is perhaps the most common effect). I'm not sure this will ever become a mainstream sensor technology. However, I do like the SD14--I just wish it had more pixels. I am prepared to buy an SD1 when it comes out, if only for use as a B+W camera (the Foveon sensor can claim to be a superior B+W imaging device).

12MP is plenty for me on a 4/3 sensor, although I would appreciate the multi-format aspect of the GH2. However, 4.7MP is on the low side...

Anders W said:

As to the Minoltas we are talking about, I certainly do not think they have anything to be ashamed of when it comes to resolution. OK, they are not macro lenses, and if you are looking for something that will be entirely satisfactory in close-up work, a real macro is of course a better bet. But for other things, I am pretty sure that the Minoltas, when stopped down to peak aperture, delivers something very close to what we can hope for given limitations of the sensor.

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I'm not saying Minolta is bad, however I would be surprised if Leica was not better, at least in some aspect (they should be for the money). It may not be in sharpness--perhaps something like bokeh which is more difficult to evaluate. I will probably rent a Leica at some point to see for myself...

Anders W said:

In fact, when I looked at your test shots a second time, I was surprised at how well the 50/1.4 is doing wide open, especially at the edge. OK. There is a clear loss of contrast, including microcontrast. But there's hardly any sign of blur. Pretty much all the details are there already at 1.4, just rendered with less contrast and thus less readily visible.

Click to expand...

Well, with legacy 35mm lenses we always have the benefit that the 'edge' on 4/3 is still pretty close to the center of the 35mm frame. Assuming the lens had good central performance, the 4/3 edge should be acceptable. My biggest surprise is that the 28mm doesn't perform well in terms of sharpness, and isn't really affected that much by stopping down. On the other hand, the contrast seems good even wide open. I expected that the 28mm would have problems due to the angle of the light rays, but I thought that would manifest as a contrast issue...

Cheers, Keith
--
http://www.kotay.net/keith/photo/photo.shtml