p.3 #1 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
dan98 wrote:
Those MTF curves resemble the performance of my Voigtlander SL 90/3.5 APO-Lanthar, specifically in terms of the pronounced mid-zone dip. I am not suggesting that the new 90/4 has the same optical design--it clearly does not--but based on the MTF curves it would seem to have the same primary flaw. If this proves to be true then it would be a disappointment. The 90/3.5 is by far the weakest of the SL APO-Lanthars and is quite an old design, so I would have expected the latest Voigtlander offering to avoid this issue.
The 90/3.5 is also the weakest of the series in terms of control of various aberrations (especially LoCA and purple fringing), and at least here I am confident that the new lens will offer improvements. I believe that the old 90/3.5 is the least APO of all of their APO-designated lenses. Based on the few sample images I have seen, the new 90 produces very little fringing. ...Show more →
To my knowledge, Cosina never published an official MTF chart for the original LTM (M39) 90mm f/3.5 APO-Lanthar from the early 2000s. I've tested this lens myself in the past and was also disappointed by its performance, especially wide open. It wasn't until f/6.3 or smaller that it matched other 85mm/90mm lenses, even ones that weren't APO-corrected at all. https://www.fredmiranda.com/forum/topic/1626686/
Having said that, I believe an MTF graph for the old 90mm f/3.5 APO-Lanthar (LTM) would show much worse performance. There's a lot of astigmatism with this lens, along with color error, so it's "APO" by the standards of another time.
I'm hopeful the new 90mm f/4 APO-Lanthar will perform similarly to the 50mm f/3.5 APO-Lanthar, which I consider outstanding based on my tests, regardless of what the graph says. It's on par with the 50mm f/2 APO-Lanthar at f/3.5, if you check the review. These are real-world tests, which is what matters most to us.
The lack of astigmatism is the key to that crisp off-axis performance, and I believe the new 90mm f/4 APO will deliver that too.
Jul 16, 2026 at 12:27 PM
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p.3 #2 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
dan98 wrote:
Those MTF curves resemble the performance of my Voigtlander SL 90/3.5 APO-Lanthar, specifically in terms of the pronounced mid-zone dip. I am not suggesting that the new 90/4 has the same optical design--it clearly does not--but based on the MTF curves it would seem to have the same primary flaw. If this proves to be true then it would be a disappointment. The 90/3.5 is by far the weakest of the SL APO-Lanthars and is quite an old design, so I would have expected the latest Voigtlander offering to avoid this issue.
The 90/3.5 is also the weakest of the series in terms of control of various aberrations (especially LoCA and purple fringing), and at least here I am confident that the new lens will offer improvements. I believe that the old 90/3.5 is the least APO of all of their APO-designated lenses. Based on the few sample images I have seen, the new 90 produces very little fringing. ...Show more →
Dan, I had the old 90 f/3.5 APO Lanthar and I totally agree with your assessment of it. It is one of the few Voigtlander lenses I have owned in which I was pretty disappointed. I noticed with my copy the same things you mentioned and I do believe it had a pretty substantial mid-zone dip.
That said, the MTF's of this 90 f/4 APO Lanthar do not show a mid zone dip. A mid zone dip is indicated by worse performance (i.e. lower percentage contrast) from 12-18mm from the center than you see in the center *and* than you see in the outer part of the frame (i.e. 18-22mm from the center). When there is a mid zone dip as the name implies performance doesn't just go down in the midfield it comes back up toward the corners.
A gradual decrease in performance from the center to the corners in not a mid-zone dip and that is what we see in the MTF curve for this new 90 f/4 APO Lanthar. This gradual decrease is a pattern that I find I typically associate with a lens that performs in ways I like. Like Fred alluded to the Voigtlander M mount 50 f/3.5 APO has this pattern too. As does the 110 f/2.5 and 65 f/2 APO Lanthar Macros for Sony E mount. As does the relatively new Voigtlander 28 f/2 APO Lanthar for M, E, and Z mounts. The pattern does suggest performance will be better in the center than in the edges and corners, but as long as the change is gradual and the performance at the edges and corners is good enough it is not a pattern that I think indicates a problem.
I totally agree with Fred, however, that the real way to evaluate this lens, and really every lens, is the sort of rigorous testing that Fred does in his reviewers. I would bet this lens is going to perform well in those tests, but of course we won't know until the tests are actually done. The few real world shots we have seen (From Juha at CP+) also seem to suggest strong performance from the lens, but his testing was necessarily limited by the venue and only a short time with the lens. It will be great to see how the lens performs when people have it for a lot longer and can thoroughly test it out.
p.3 #3 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
Fred Miranda wrote:
To my knowledge, Cosina never published an official MTF chart for the original LTM (M39) 90mm f/3.5 APO-Lanthar from the early 2000s. I've tested this lens myself in the past and was also disappointed by its performance, especially wide open. It wasn't until f/6.3 or smaller that it matched other 85mm/90mm lenses, even ones that weren't APO-corrected at all. https://www.fredmiranda.com/forum/topic/1626686/
Having said that, I believe an MTF graph for the old 90mm f/3.5 APO-Lanthar (LTM) would show much worse performance. There's a lot of astigmatism with this lens, along with color error, so it's "APO" by the standards of another time.
I'm hopeful the new 90mm f/4 APO-Lanthar will perform similarly to the 50mm f/3.5 APO-Lanthar, which I consider outstanding based on my tests, regardless of what the graph says. It's on par with the 50mm f/2 APO-Lanthar at f/3.5, if you check the review. These are real-world tests, which is what matters most to us.
The lack of astigmatism is the key to that crisp off-axis performance, and I believe the new 90mm f/4 APO will deliver that too....Show more →
There is an official MTF chart for the 90/3.5, and it can be found in the thread you linked above (p.1, #9). It is quite consistent with the performance that I have observed with the lens, showing the mid-frame dip.
In terms of sharpness, various tests and user reports of the 90/3.5 are all over the map. While to some extent this reflects variation among users, it also likely reflects sample variation. For example, Klaus at Photozone found that the SL version was significantly better than the LTM version that you tested (a point made in the thread you linked). Since the optics are supposedly the same, and since the testing methodology was the same, this is surely a sign of sample variation. With my copy the corners are very sharp (just a tiny bit worse than the center), but there is a mid zone that is soft. Others report soft corners. Of course it would not be the only CV lens to be plagued by sample variation. The one area where there seems to be a solid consensus is that the 90/3.5 is not really apochromatic; not by the standards of any era.
I hope that you are right about the new lens being sharp across the frame, although I am a tad skeptical based on the MTF graph. I agree that real-world tests are more important than MTF graphs, so it would be foolish to rush to judgment. I also agree that correction of aberrations is important, and it is all but certain that the new lens will be much improved in that regard.
p.3 #4 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
dan98 wrote:
There is an official MTF chart for the 90/3.5, and it can be found in the thread you linked above (p.1, #9). It is quite consistent with the performance that I have observed with the lens, showing the mid-frame dip.
I was referring to the M39 mount version. I believe the MTF chart shared in that thread (with no known source) is for the SL version and appears to be computer-generated rather than based on actual measurements, even though the optical design is the same. My guess is that it originated from Nikon rather than Cosina.
After shooting extensively with the LTM (M39) version, I simply don't trust that MTF chart. In my experience, it does not accurately represent my copy of this lens's real-world performance.
p.3 #5 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
Steve Spencer wrote:
Dan, I had the old 90 f/3.5 APO Lanthar and I totally agree with your assessment of it. It is one of the few Voigtlander lenses I have owned in which I was pretty disappointed. I noticed with my copy the same things you mentioned and I do believe it had a pretty substantial mid-zone dip.
That said, the MTF's of this 90 f/4 APO Lanthar do not show a mid zone dip. A mid zone dip is indicated by worse performance (i.e. lower percentage contrast) from 12-18mm from the center than you see in the center *and* than you see in the outer part of the frame (i.e. 18-22mm from the center). When there is a mid zone dip as the name implies performance doesn't just go down in the midfield it comes back up toward the corners.
A gradual decrease in performance from the center to the corners in not a mid-zone dip and that is what we see in the MTF curve for this new 90 f/4 APO Lanthar. ...
.......Show more →
While there is just a gradual decrease from the center to the corners at 10 lp/mm (which is not a mid-zone dip), there is a pronounced dip at 30 lp/mm and 40 lp/mm in the sagital direction. This is most pronounced at 30 lp/mm and f/5.6, where the value hits a trough at about 12-13mm, and then rises steadily as we move out to 18%, but only for the sagital. This is exactly the same pattern as the MTF curve for the 90/3.5 at f/3.5. In the sagital direction a trough occurs at 12-13%, with the value rising steadily as we move out to 18mm. With both lenses the dip in the MTF curve only occurs in the sagital direction. Regarding the magnitude of the dip, it is is slightly more pronounced with the new lens, although they are really quite similar. It is this similarity that has me concerned, but I agree that the real-world results are what matters.
p.3 #6 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
Fred Miranda wrote:
I was referring to the M39 mount version. I think that MTF shared on that thread is for the SL version and is computer generated rather than based on actual measurements, even though the optical design is the same. My guess is that it came from Nikon, not Cosina. After shooting extensively with the LTM (M39) version, I simply don't trust that MTF chart. In my experience, it does not accurately represent my copy of this lens's real-world performance.
I assume you mean that it does not reflect the real world performance of your copy of the lens. It matches up pretty well with my copy. Either there is sample variation or there are some unreported differences between the LTM and SL versions. My copy is sharp wide open in the center and near the edge of the frame, but that mid-zone dip spoils the party. It's not that the sharpness is terrible in mid zone, but the drop in relative sharpness is very annoying. And of course the LoCA and purple fringing are inexcusable.
p.3 #7 · Cosina Voigtländer APO-Lanthar 90/4 VM officially announced for August release
Steve Spencer wrote:
I'm not sure what you were expecting, .
given the uncritical focal length and the very modest aperture I expected the MTF curves to be quite flat, but they aren't;
especially since wide open they're not, I expected some improvement on stopping down, which there isn't.
