Huck Finn
Well-known
Erwin's third & final installment of his review of the Zeiss lenses is now complete& is posted on his website. Can anyone explain to me what he means by the term "spatial resolution" in his Conclusions section? Thanks. - Huck
Puts Review of ZM Lenses: Part III
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Todd.Hanz
Guest
"spatial" is a term used in the south, akin to the word special used in the rest of the country.
If Erwin says a lens has "spatial resolution" he's saying the lens is out of the ordinary, and very good 😀.
Todd
If Erwin says a lens has "spatial resolution" he's saying the lens is out of the ordinary, and very good 😀.
Todd
tetrisattack
Maximum Creativity!
Puts says "spatial resolution" when he means lines-per-millimeter, and by "tonal resolution" I think he's just talking about color accuracy. 😉
Y'know, this was a good series about a great set of lenses, but it's telling that at the end of every piece he decides he favors leica for reasons that are essentially unquantifiable.
Any optical engineers in the house? I'd love to know more about the mechanics behind this comment about the 50 planar:
"The lens is especially good at recording detail in extended shadow zones, when you take pictures at dusk or at night."
I made the same observation myself after trying out the 50, but wrote it off as a developer anomaly. After all, how can a lens have better contrast separation AND more shadow detail?
Y'know, this was a good series about a great set of lenses, but it's telling that at the end of every piece he decides he favors leica for reasons that are essentially unquantifiable.
Any optical engineers in the house? I'd love to know more about the mechanics behind this comment about the 50 planar:
"The lens is especially good at recording detail in extended shadow zones, when you take pictures at dusk or at night."
I made the same observation myself after trying out the 50, but wrote it off as a developer anomaly. After all, how can a lens have better contrast separation AND more shadow detail?
einolu
Well-known
whats the website?
peter_n
Veteran
aizan
Veteran
before: leica glow. after: leica sparkle.
Mazurka
Well-known
And don't you forget...
And don't you forget...
...the brilliance of the Leica lenses! 😀
He says he's going to close down his website - I believe he will resurrect it when Leica announces a whole new range of digital products ("co-developed" with Panasonic, of course) to replace the existing film-based offerings. 😛
And don't you forget...
...the brilliance of the Leica lenses! 😀
He says he's going to close down his website - I believe he will resurrect it when Leica announces a whole new range of digital products ("co-developed" with Panasonic, of course) to replace the existing film-based offerings. 😛
jlw
Rangefinder camera pedant
Coming soon to an image editor near you:
DaveSee
shallow depth of field
Brings pause that Erwin will, in his words:
"So for the moment I will stop developing this site and will remove it from the web in a short period. "
Odd, that a fella concerned with LPM uses "short period" to announce his *site* closing.
WRT Zeiss lenses would he shut down? No, it's the LPM stuff, IMHO. CCDs and CMOS tech
*blurs* this perspective.
Yes, Leica has produced some, just *some*, great glass. Zeiss--and others--have too. But shooting RF is glass, RF, VF and all of that in your hands: the system as it's known(and loved).
What does he mean by "spatial resolution"? I cannot say... but I'd suspect he is opening a
door towards glass that is "digital ready." He *did* invoke the magic word "bo-ke"... and
just what is that? Answer: your image of what you want seen... soft or hardware.
I am thankful that he, Erwin, took the time to investigate and comment on these lenses...
and that his interest, freely offered, has been given: he has provided a subjective POV to my "spatial resolution." And I use Leica and CV glass... and not because of his reviews. I mean, how could he know what I want to photograph? He has no clue, thankfully.
rgds,
Dave
"So for the moment I will stop developing this site and will remove it from the web in a short period. "
Odd, that a fella concerned with LPM uses "short period" to announce his *site* closing.
WRT Zeiss lenses would he shut down? No, it's the LPM stuff, IMHO. CCDs and CMOS tech
*blurs* this perspective.
Yes, Leica has produced some, just *some*, great glass. Zeiss--and others--have too. But shooting RF is glass, RF, VF and all of that in your hands: the system as it's known(and loved).
What does he mean by "spatial resolution"? I cannot say... but I'd suspect he is opening a
door towards glass that is "digital ready." He *did* invoke the magic word "bo-ke"... and
just what is that? Answer: your image of what you want seen... soft or hardware.
I am thankful that he, Erwin, took the time to investigate and comment on these lenses...
and that his interest, freely offered, has been given: he has provided a subjective POV to my "spatial resolution." And I use Leica and CV glass... and not because of his reviews. I mean, how could he know what I want to photograph? He has no clue, thankfully.
rgds,
Dave
Cute! I do like that dialog box.. 🙂
aizan
Veteran
hey, manolo, just noticed your user title. it wouldn't make sense as a title, but you can also look at it as chimps are 99% human. (i think it's about 98%, though).
jaapv
RFF Sponsoring Member.
Huck Finn said:
Maybe I understand him because I'm Dutch as well 😀 I think he means that the resolution rendering of 3-dimensional objects is not necessarily the same as resolution in terms of lines/mm, which is obviously 2-dimensional. See the book of Richard Daley, (of which I have the German translation): Leica Objective in der Praxis, the section about lens testing.
jaapv
RFF Sponsoring Member.
tetrisattack said:
Couldn't it be that that is just what it is- unquantifiable? In the end Leica fans do buy their lenses for the "optical signature" just as Zeiss or CV fans do. I do not think that any testing method can differentiate between lenses on that criterium, at this level of quality we are talking about individual taste of the user, thankfully.
VinceC
Veteran
>>In the end Leica fans do buy their lenses for the "optical signature" just as Zeiss or CV fans do.<<
I think, too, that photographers buy their lenses based on the photographic system that fate puts into their hands, through research or accident. Most people seem to end up with a particular camera system, then start obtaining the lenses which are available for that system, based on a mixture of cost and quality.
I think, too, that photographers buy their lenses based on the photographic system that fate puts into their hands, through research or accident. Most people seem to end up with a particular camera system, then start obtaining the lenses which are available for that system, based on a mixture of cost and quality.
jlw
Rangefinder camera pedant
The term "spatial" isn't unique to Erwin -- it comes from the world of MTF (modulation transfer function) testing, which laboratories use to quantify the performance of lenses.
In MTF, the lens being tested is used to image a pattern of sharply-defined bars spaced a certain distance apart (the "spatial frequency" -- how often the bar pattern repeats in the space it takes up, such as 5 cycles per mm.) The image formed of this pattern is scanned with a light sensor, and its brightness values are displayed as a graph.
This graph resembles the graph of a sound wave, which also is composed of a repeating pattern, and can be analyzed using similar mathematical techniques. The difference is that for the lens, the pattern repeats in the "spatial domain," whereas the sound wave's pattern repeats in the time domain -- so testers have to use the term "spatial" to make it clear which type of wave they're describing.
So, when Erwin talks about "spatial resolution," he is talking about the ability to resolve (distinguish) the elements of a finely repeating pattern, probably based on his reading of MTF test results.
In MTF, the lens being tested is used to image a pattern of sharply-defined bars spaced a certain distance apart (the "spatial frequency" -- how often the bar pattern repeats in the space it takes up, such as 5 cycles per mm.) The image formed of this pattern is scanned with a light sensor, and its brightness values are displayed as a graph.
This graph resembles the graph of a sound wave, which also is composed of a repeating pattern, and can be analyzed using similar mathematical techniques. The difference is that for the lens, the pattern repeats in the "spatial domain," whereas the sound wave's pattern repeats in the time domain -- so testers have to use the term "spatial" to make it clear which type of wave they're describing.
So, when Erwin talks about "spatial resolution," he is talking about the ability to resolve (distinguish) the elements of a finely repeating pattern, probably based on his reading of MTF test results.
jlw
Rangefinder camera pedant
jaapv said:
Sure, I think it's very plausible that the "Leica look" is unquantifiable.
What makes a lot of us suspicious, I think, is that Leica lens pricetags are highly quantifiable (not to mention large.) When those who can afford to pay those prices tell us that they're worth it on the grounds of factors that the rest of us can't even see, we're inclined to suggest that someone is putting us on.
I try to be a little more sympathetic, though, because I realize that pricing things based on unquantifiable factors happens all the time: buying symphony tickets for example. You expect to pay a lot more for a ticket to, say, the Philadelphia Orchestra than to the Podunk Community Symphony... and most people will wind up agreeing that the Philly sounds better, even though only a classical music buff will be able to explain why, and that explanation might not make sense to anyone else.
Where it gets a little dodgier, as you suggest, is in the area where taste intersects with quality. I run into this situation all the time when I go to ballet performances: a big-name nationally touring company (the equivalent in this strained analogy of the Leica lens) always will do a workmanlike job, but sometimes I'm more excited by the performance of a gutty little regional company, because they emphasize qualities that are more in sync with my own taste.
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