Bertram2
Gone elsewhere
tedwhite said:
Something proving things which neither you nor your film can ever see.
It was invented once for blind photogs, to give them something to argue about, and let them take part too at the great eternal lens talk.
Speenth
Emmaiter
tedwhite said:
Its a long time since I studied this, but as I recall (and leaving aside the complex theory and maths) modulation transfer function (MTF) is an absolute measure of the limiting resolution of an imaging medium. Importantly, the difference in the density (in terms of amplitude) of the adjacent components resolved (i.e. contrast) is the basis of MTF. Thus MTF takes into account the size of the objects resolved, their proximity to each other and their relative densities, together with the density of the intervening spaces.
Line pair tools used for the physical measurement of resolution (i.e. the number of lines and adjacent spaces per millimetre (lp/mm) that a system can resolve) has its basis in MTF. Thus MTF measures both the frequency and amplitude of the items that make up a resolved image - sharpness and contrast in a photographer's language.
1 line pair = one object and one space beside it. Thus one high density item and one low density item.
I doubt I'm making sense, but MTF is the stuff of physics PhDs!
Last edited:
JTK
Established
I use two CVs, two Canons (not Serenars), and a Leica. CV aren't nearly as well-built as the others but the glass is nice.
PaulDalex
Dilettante artist
Look Bertram2,
MTF is a standard concept in scientific literature. Frequency analysis was a main stream tool in Control theory at the end of the forties. I remember the book by Truxal on Automatic control synthesis I read as a student in 1965 (Amazon still has it), which is entirely based on frequency analysis.
Similarly in Optics. The literature is immense in both disciplines. For Optics a classical reference is:
Principles of Optics, by Max Born and Emil Wolf, Cambridge, first edition 1959.
After my degree I taught frequency analysis for decades. Now all this is rather outdated (in Control), but it holds good anyway, and has remained main stream in Optics.
You and me and all other human beings can escape anything but Math and its Theorems.
So if you have good eyes for photos, you will be able to see what MTF says, and if you know MTF you have a very precise idea of what to expect, even before buying a lens, so to make informed decisions.
Cheers
Paul
MTF is a standard concept in scientific literature. Frequency analysis was a main stream tool in Control theory at the end of the forties. I remember the book by Truxal on Automatic control synthesis I read as a student in 1965 (Amazon still has it), which is entirely based on frequency analysis.
Similarly in Optics. The literature is immense in both disciplines. For Optics a classical reference is:
Principles of Optics, by Max Born and Emil Wolf, Cambridge, first edition 1959.
After my degree I taught frequency analysis for decades. Now all this is rather outdated (in Control), but it holds good anyway, and has remained main stream in Optics.
You and me and all other human beings can escape anything but Math and its Theorems.
So if you have good eyes for photos, you will be able to see what MTF says, and if you know MTF you have a very precise idea of what to expect, even before buying a lens, so to make informed decisions.
Cheers
Paul
elude
Some photographer
"Pas assez chère mon fils"
Bertram2
Gone elsewhere
Some of it only, which is within the limits of perception. And from that part is relevant only what film can reproduce.
If you taught transmission for decades you will know that better than I do.
if you want to know if a lens is good enuff for your personal quality standard take some slides and project them with a good lens. What you cannot see is not relevant, opposite to what some esoterics say .
You don't need maths for that. MTF is fetishism for people who cannot sleep at night if they aren't sure that they use the best of the best glass. And who waste 90% of the expensive performance by shooting 1/4 sec handheld tho beeing not able to hold a camera steady.That is my personal experience.
Reading MTFs probably gives you an idea of what your expectations could be , but it says nothing about the whole lens and not if it will really match your expectations.
bertram
myoptic3
Well-known
The VC lenses can be very good. You have to do your research to find the best ones. My 35 2.5 was very sharp. But the thing the VC lenses don't do to my knowledge, nor other lenses for that matter, is give you a particular, signature look and sometimes a very 3-D look like the older Leica glass. I like that look. The hogwash about "Leica glow" is just that, but there IS something about the way certain classic Leica lenses make images in a very particular way.
monster
Established
i think every lens have they own character
Patman
Established
Missed a category, have one and it isn't very good.
jwhitley
Established
A very simple reason, in my case: because I don't yet have an M-mount camera body.
raid
Dad Photographer
I prefer old Leica and Canon lenses over other types of lenses. There is no obvious reason why I prefer not to buy CV lenses other than I value the history of a lens. It may sound illogical to go with such a factor, but that's the beauty of this hobby; we can choose our own preferences.
Arvay
Obscurant
I've got few : 15, 25, 35/1.7, 50/1.5, 75/2.5
They all suit my expectations
Anyway I'm going to have a Zeiss 35/2 and maybe a true planar as I like it
They all suit my expectations
Anyway I'm going to have a Zeiss 35/2 and maybe a true planar as I like it
le vrai rdu
Well-known
vouzici [:gnub]
bottley1
only to feel
just bought the CV 75mm f2.5, because the equivalent Leica or Zeiss are just too expensive for me. Early results are stunning to say the least...lovely lens. Its a good time to be a M mount camera owner, such choice!
peterleyenaar
Member
CV 75mm
CV 75mm
I also have that lens, it is very good, for my eyes as good as the Leica lenses, of which I have owned nearly everyone at one time or another.
CV 75mm
I also have that lens, it is very good, for my eyes as good as the Leica lenses, of which I have owned nearly everyone at one time or another.
Ororaro
Well-known
Every M bag needs a 15mm lens, and since VC is the only affordable game in town...
swoop
Well-known
I've had the 35mm f1.2 Nokton and it was a great lens. But it fell apart on me. I currently have the 40mm f1.4 Nokton. And it's a great lens too. But its look is definitely different from Leica's offerings.
louisb
Well-known
Leica snob (no more)
Leica snob (no more)
I was a complete Leica snob until about 5 days ago when I needed a portrait lens in a hurry for my M8 because my lux35-asph has been languishing in Solms for 8 weeks waiting to be coded. After some research I settled on a CV 50/1.5 Nokton in preference over a cron50 or sonnar1.5.
Wow! The results are so impressive I put my 75cron on e-bay, sold it pretty much immediately and used the cash to pay for the CV 50 and purchase a s/h 90cron-apo which is a more useful focal length for me on the M8.
Unfortunately, I do not have a relase yet to post the portrait work but the crispness and colour drawing, plus the bokeh of the 50/1.5 was equivalent to my 75cron for a fraction of its cost.
I'm now eyeing up a 28/3.5 skopar and thinking about seeing whether the 35/1.4 can replace my too valuable to keep 35lux when it returns.
Leica snob (no more)
I was a complete Leica snob until about 5 days ago when I needed a portrait lens in a hurry for my M8 because my lux35-asph has been languishing in Solms for 8 weeks waiting to be coded. After some research I settled on a CV 50/1.5 Nokton in preference over a cron50 or sonnar1.5.
Wow! The results are so impressive I put my 75cron on e-bay, sold it pretty much immediately and used the cash to pay for the CV 50 and purchase a s/h 90cron-apo which is a more useful focal length for me on the M8.
Unfortunately, I do not have a relase yet to post the portrait work but the crispness and colour drawing, plus the bokeh of the 50/1.5 was equivalent to my 75cron for a fraction of its cost.
I'm now eyeing up a 28/3.5 skopar and thinking about seeing whether the 35/1.4 can replace my too valuable to keep 35lux when it returns.
Last edited:
photobizzz
Speak of the Devil
I see the 50 Heliar in your signature line, I have only heard praise for this lens and every photo I have seen was super sharp, I dont understand your criticism.
I just sold my 50 Cron and bought a 50/2 Heliar...to each his own I guess.
Last edited:
raid
Dad Photographer
Each time I see the title of this thread, I feel like saying: "I already have told you why.". It would be better titled " Why would you buy a CV Lens?".
L E I C A
Zeiss
Other
L E I C A
Zeiss
Other