raul jarquin wrote:
Saxguy, do you use the 50 1.4 ZA most of the time because it has AF or because of some other reason?
I have a Loxia 50 and the 50 1.4 ZA. They complement each other very well but the idea of having one small lens that can do it all is very appealing if all else is equal...
I use AF more because of the subjects I photograph. I will use MF with it occassionally. I also do a fair amount of conversion to monochrome when I use it. I think the CV50 APO may edge it out in monochrome conversion, but I still tend to photograph moving subjects and people more at 50mm than anything else. AF-C and Eye-AF helps in that regard.
Jan 28, 2020 at 08:05 AM
Steve Spencer Online • • • • • • • Upload & Sell: On
pdmphoto wrote:
The levels of purple fringing in that tree shot is high for any lens. Use the link provided to view it at 100%. I am very surprised at that level of PF for an APO designated lens. I don't think even my old Sigma's from the 80's (180/5.6 APO macro, or 180/2.8 APO macro) have have ever shown that level.
Very hard to know without a side by side comparison. If this were typical for the lens that would be one thing, but CA can be extreme in so conditions because of the conditions and without a side by side comparison the results we see might not tell us much about the lens and only a lot about the conditions.
I'm not sure it's due to user error or copy variation (probably the former), but I have not been able to replicate (in near identical conditions) the fringing other members have reported. Maybe the time of the day might have something to do with it - different wavelengths & all.
The truth is that the Voigtlander 50/2 APO has excellent axial CA performance when compared to other 45-55mm lenses and it's pretty much free of lateral CA.
Longer native lenses like the CV 65/2, 110/2.5 and Batis 135/2.8 are better corrected but let's not forget they are not 50mm!
Anyone owns the Leica 50 Summicron f/2 APO (M or SL) for a side by side axial CA test comparing them to the CV 50/2 APO? Although not the same price/size, at least they share the same FL and maximum aperture.
Fred Miranda wrote:
The truth is that the Voigtlander 50/2 APO has excellent axial CA performance when compared to other 45-55mm lenses and it's pretty much free of lateral CA.
Longer native lenses like the CV 65/2, 110/2.5 and Batis 135/2.8 are better corrected but let's not forget they are not 50mm!
Anyone owns the Leica 50 Summicron f/2 APO (M or SL) for a side by side axial CA test comparing them to the CV 50/2 APO? Although not the same price/size, at least they share the same FL and maximum aperture.
Fred, if I'm not mistaken you own both, the CV 50 and the 65. If so, could you please do a direct comparison in a high-contrast situation? I'm not convinced that the 65 is much better.
I'm not sure it's due to user error or copy variation (probably the former), but I have not been able to replicate (in near identical conditions) the fringing other members have reported. Maybe the time of the day might have something to do with it - different wavelengths & all.
pdmphoto wrote:
The levels of purple fringing in that tree shot is high for any lens. Use the link provided to view it at 100%. I am very surprised at that level of PF for an APO designated lens. I don't think even my old Sigma's from the 80's (180/5.6 APO macro, or 180/2.8 APO macro) have have ever shown that level.
Yeah, I wouldn't judge the lens based on that photo, particularly not against a moderate tele that couldn't achieve that same framing without digging a hole from which to shoot.
The problem is spherocromatism. The trees are before the plane of focus and chimneys (which have as much green fringing as the trees do magenta) are behind the plane of focus, and, traditionally, that isn't a type of CA completely corrected in lenses with the APO label (or Canon's L lenses and Nikon's ED's). Even today, there's only a handful of lenses between 35 and 65 that would perform at a higher level once color and contrast have been normalized, and they are all much larger lenses.
Better, I think, to ask if you would ever frame a shot like that with that narrow a depth of field. If so, why?
realVivek wrote:
Well, doubts from speculations and curiosities can only be solved one way.
I speak from my experience. I also recommend that you use the lens with a strong UV filter.
Well, I have done just that. My initial tests around the house (raining heavy outside) have not swayed me much in a positive direction from my very sharp copy of the Zony 55/1.8 I am testing it against.
pdmphoto wrote:
Well, I have done just that. My initial tests around the house (raining heavy outside) have not swayed me much in a positive direction from my very sharp copy of the Zony 55/1.8 I am testing it against.
I love the CV 2/50; but you shouldn't expect magic from any lens, and in many situations the difference between them is going to be minor. The CV will be a touch sharper wide open *if your technique is perfect* - but both are plenty sharp enough.
The CV has a little more contrast.
The ZA has rather more axial colour, so you'll find green outlining on rear bokeh balls etc at wider apertures
The ZA has more 'onion rings' in situations where the bokeh balls are large.
It could well be you haven't yet encountered any of these situations, and for all I know given your shooting preferences you never will!
The manual focus is not very easy to use on the ZA.
If you prefer an AF lens, there is not that much reason to sacrifice that for the Apo-Lanthar. If you prefer a manual heliocoid, or if it's swings and roundabouts for you, then get the Apo-Lanthar.
Fred Miranda wrote:
The truth is that the Voigtlander 50/2 APO has excellent axial CA performance when compared to other 45-55mm lenses and it's pretty much free of lateral CA.
Longer native lenses like the CV 65/2, 110/2.5 and Batis 135/2.8 are better corrected but let's not forget they are not 50mm!
Anyone owns the Leica 50 Summicron f/2 APO (M or SL) for a side by side axial CA test comparing them to the CV 50/2 APO? Although not the same price/size, at least they share the same FL and maximum aperture.
Anyone doing that test please don't just look for PF; PF is fairly easy to correct. But spherochromatism (the axial colour aberration that makes the colour of bokeh overall muddy due to green-magenta aberrations in the bokeh) is extremely hard to correct and matters, at least to me, much more. As well as showing in much lower contrast situations. So looking for that, either by looking at bokeh balls, or the old ruler test (at exactly same distances and so forth of course) would help.
DavidBM wrote:
Anyone doing that test please don't just look for PF; PF is fairly easy to correct. But spherochromatism (the axial colour aberration that makes the colour of bokeh overall muddy due to green-magenta aberrations in the bokeh) is extremely hard to correct and matters, at least to me, much more. As well as showing in much lower contrast situations. So looking for that, either by looking at bokeh balls, or the old ruler test (at exactly same distances and so forth of course) would help.
We have had bokeh ball and ruler tests several pages back, no need for more.
Maybe I am mistaken, but isn't purple fringing the same thing as longitudinal CA?
[edit]
Looks like PF is mostly caused by LoCA. From Wikipedia: "The term purple fringe used to describe one aspect of chromatic aberration dates back to at least 1833.[1] However, Brewster's description with a purple fringe on one edge and a green fringe on the other is a lateral chromatic aberration. A general defocus of the shortest wavelengths resulting in a purple fringe on all sides of a bright object is the result of an axial or longitudinal chromatic aberration. Quite often, these effects are mixed in an image."
Other sources are plausible, but are mostly hypothetic (without reference / proof). "Purple fringing is usually attributed to chromatic aberration as described above, although it is not clear that all purple fringing can be explained this way[citation needed]. Other attributed causes of purple fringing in digital photography include many hypothesized sensor effects..."
I can rule out the second possibility quoted, namely the sensor effect (based on the coatings). I see similar fringing on a “full spectrum” (just with the clear glass cover) or a thin sensor mod (0.7mm blue green glass instead of the clear glass cover on the sensor) sony A7 cameras.
keepcoding wrote:
We have had bokeh ball and ruler tests several pages back, no need for more.
Maybe I am mistaken, but isn't purple fringing the same thing as longitudinal CA?
[edit]
Looks like PF is mostly caused by LoCA. From Wikipedia: "The term purple fringe used to describe one aspect of chromatic aberration dates back to at least 1833.[1] However, Brewster's description with a purple fringe on one edge and a green fringe on the other is a lateral chromatic aberration. A general defocus of the shortest wavelengths resulting in a purple fringe on all sides of a bright object is the result of an axial or longitudinal chromatic aberration. Quite often, these effects are mixed in an image."
Other sources are plausible, but are mostly hypothetic (without reference / proof). "Purple fringing is usually attributed to chromatic aberration as described above, although it is not clear that all purple fringing can be explained this way[citation needed]. Other attributed causes of purple fringing in digital photography include many hypothesized sensor effects..."...Show more →
Puple fringing is an axial (longitudinal) aberration but not the only one. Spherochromatism is another.
The purple and green edges to in focus elements are generally lateral CA. Easy to fix
But the green edges to *out of focus* elements, especially secular highlights, pink centres, and magenta edges in front of the plane if best focus are axial aberrations, and make things look very muddy sometimes, and is hard to correct without side effects. Generally this axial problem is attributed to spherochromatism.
The biggest benefit of apochromatic designs, in my book, is the reduction in this second hard to fix axial aberration.
Lateral aberrations are easily fixed (in the Sony world often compulsorily fixed for you by the metadata instructing the raw converter)
PF axial aberrations aren’t as simple as LaCA to fix, but the effect in modern lenses can be tamed easily with the fringing tool usually with little ill effect.
But spherochromatism is a pain to fix in post, so lenses with minimal levels are very welcome.
DavidBM wrote:
Puple fringing is an axial (longitudinal) aberration but not the only one. Spherochromatism is another.
The purple and green edges to in focus elements are generally lateral CA. Easy to fix
But the green edges to *out of focus* elements, especially secular highlights, pink centres, and magenta edges in front of the plane if best focus are axial aberrations, and make things look very muddy sometimes, and is hard to correct without side effects. Generally this axial problem is attributed to spherochromatism.
The biggest benefit of apochromatic designs, in my book, is the reduction in this second hard to fix axial aberration.
Lateral aberrations are easily fixed (in the Sony world often compulsorily fixed for you by the metadata instructing the raw converter)
PF axial aberrations aren’t as simple as LaCA to fix, but the effect in modern lenses can be tamed easily with the fringing tool usually with little ill effect.
But spherochromatism is a pain to fix in post, so lenses with minimal levels are very welcome.
I think you are mixing different terms:
spherochromatism = chromatic aberrations (CA)
purple fringing (PF) = magenta ghosting (mostly LoCA)
axial CA = longitudinal CA (LoCA)
lateral CA (LaCA)
And yes, the strength of APO is the correction of LoCA, not LaCA.
