Leica 35mm Summicron KOB copy by ‘Mandler’
p.7 #1Leica 35mm Summicron KOB copy by ‘Mandler’
Because it’s a little slower than f/2, probably closer to f/2.5. And the price point is similar.
Jul 24, 2026 at 01:02 PM
p.7 #2Leica 35mm Summicron KOB copy by ‘Mandler’
RustyRus wrote:
They borrowed a famous name and released a lens that looks like an original Leica 35mm Summicron.
Beyond the appearance, it is not particularly impressive, does not render anything like the original, and seems to be relying heavily on the name to sell lenses.
In my opinion, there are far better brands to spend your money on.I understand your opinion, but unless you have tried this lens against the original and had bad results, how can you say "does not render anything like original"?
I own the KOB from Germany and the original KOB from Canada. The Mandler KOB performs just like they do, so what "far better brands to spend your money on" are you referring to?
IMHO, in this case, spending more for the original gets you only a bank account with less funds in it.
I’m simply summarizing Bastian’s review. Looking through the sample images he posted, it’s also clear that the lenses don’t have the same maximum aperture. Beyond that, their rendering is noticeably different.
So just out of the gate when copying a lens, you should probably try and get the aperture correct-
Glad you like yours though!!! I am assuming you will be selling your Leica's?
See post p5#6. Focus on green leaves at base of plant. Must dial up my original KOB's, but I remember they looked the same.
Whoever this Bastian guy is he borrowed one and we have no idea about variations with copies. Perhaps as a German he is tired of China knock offs entering the market time and time again. Plus he is one opinion of this lens since many here seem to like it f2.0 or f2.5.
For $350 I am surprised how well made mine is in fact. Want a Leica clone-this is the one to have IMHOO (owners opinion).
stgrove wrote
RustyRus wrote
So, in short:They borrowed a famous name and released a lens that looks like an original Leica 35mm Summicron.
Beyond the appearance, it is not particularly impressive, does not render anything like the original, and seems to be relying heavily on the name to sell lenses.
In my opinion, there are far better brands to spend your money on.
I own the KOB from Germany and the original KOB from Canada. The Mandler KOB performs just like they do, so what "far better brands to spend your money on" are you referring to?
IMHO, in this case, spending more for the original gets you only a bank account with less funds in it.
So just out of the gate when copying a lens, you should probably try and get the aperture correct-
Glad you like yours though!!! I am assuming you will be selling your Leica's?
See post p5#6. Focus on green leaves at base of plant. Must dial up my original KOB's, but I remember they looked the same.
Whoever this Bastian guy is he borrowed one and we have no idea about variations with copies. Perhaps as a German he is tired of China knock offs entering the market time and time again. Plus he is one opinion of this lens since many here seem to like it f2.0 or f2.5.
For $350 I am surprised how well made mine is in fact. Want a Leica clone-this is the one to have IMHOO (owners opinion).
Jul 24, 2026 at 01:23 PM
p.7 #3Leica 35mm Summicron KOB copy by ‘Mandler’
stgrove wrote:
RustyRus wrote
stgrove wrote
RustyRus wrote
So, in short:They borrowed a famous name and released a lens that looks like an original Leica 35mm Summicron.
Beyond the appearance, it is not particularly impressive, does not render anything like the original, and seems to be relying heavily on the name to sell lenses.
In my opinion, there are far better brands to spend your money on.
I own the KOB from Germany and the original KOB from Canada. The Mandler KOB performs just like they do, so what "far better brands to spend your money on" are you referring to?
IMHO, in this case, spending more for the original gets you only a bank account with less funds in it.
So just out of the gate when copying a lens, you should probably try and get the aperture correct-
Glad you like yours though!!! I am assuming you will be selling your Leica's?
Whoever this Bastian guy is he borrowed one and we have no idea about variations with copies. Perhaps as a German he is tired of China knock offs entering the market time and time again. Plus he is one opinion of this lens since many here seem to like it f2.0 or f2.5.
For $350 I am surprised how well made mine is in fact. Want a Leica clone-this is the one to have IMHOO (owners opinion).
Ah you know he’s just a guy who does some of the best lens reviews out there. Let’s throw some shade at him because you don’t like his conclusion on one particular lens 😂
And no he’s not biased against Chinese lenses, quite the contrary. He’s occasionally quite harsh on Leica lenses that aren’t that impressive, e.g the 50mm Noctilux.
Jul 24, 2026 at 02:35 PM
p.7 #4Leica 35mm Summicron KOB copy by ‘Mandler’
RustyRus wrote:
How is the most obvious competitor not the lens its trying to copy?
Doesn't that say a lot about this lens/brand in itself?
Part of the reason you said you like this brand was matching optical signatures- This is all bark no bite from Mandler right now IMO-
Also I am all for new lenses and more accesible options- Money can only be spread across so many brands before all ships start to sink. This one just seems like a marketing company grabbing cash vs putting real effort into the re-creation beyond aesthetics-
I'll say this again: IMO, the original Leica KOB is one of least inspiring Leica lenses I've ever owned, and that's a Leica CLAed made in Germany version. The Mandler version might be based on the KOB, but to me it's a completely different and better animal because it has better color saturation, contrast, central sharpness, and more field curvature. That combination probably baffles some who prefer the lower field curvature of the Leica version. To me, the Mandler images simply have more impact, better 3d separation of subjects wide open. The drawback to the Mandler is the field curvature makes shooting infinity landscape a challenge unless you either fight the lens using f/11 or you roll with it at f/5.6 and make sure the center of the frame is compositionally where you want the viewer's attention.
And for build quality: you won't get close to the build quality of the Mandler aluminum version unless you get the German made version of the KOB, which is still a notch below the Mandler. And you won't get the build quality of the Mandler silver brass version unless you're willing to fork over $6K for a mint copy of the silver brass version of the KOB.
Jonas Rask has been posting some images on IG with the Mandler lately, including landscape. That guy doesn't burn time with lenses that produce crap results.
raizans wrote
Still no comparisons with the 35mm f/2.5 Color-Skopar, the most obvious competitor.Doesn't that say a lot about this lens/brand in itself?
Part of the reason you said you like this brand was matching optical signatures- This is all bark no bite from Mandler right now IMO-
raizans wrote
Making classic optical signatures in matching barrel styles for brand new rangefinder lenses *accessible* for more people, especially younger demographics.I'll say this again: IMO, the original Leica KOB is one of least inspiring Leica lenses I've ever owned, and that's a Leica CLAed made in Germany version. The Mandler version might be based on the KOB, but to me it's a completely different and better animal because it has better color saturation, contrast, central sharpness, and more field curvature. That combination probably baffles some who prefer the lower field curvature of the Leica version. To me, the Mandler images simply have more impact, better 3d separation of subjects wide open. The drawback to the Mandler is the field curvature makes shooting infinity landscape a challenge unless you either fight the lens using f/11 or you roll with it at f/5.6 and make sure the center of the frame is compositionally where you want the viewer's attention.
And for build quality: you won't get close to the build quality of the Mandler aluminum version unless you get the German made version of the KOB, which is still a notch below the Mandler. And you won't get the build quality of the Mandler silver brass version unless you're willing to fork over $6K for a mint copy of the silver brass version of the KOB.
Jonas Rask has been posting some images on IG with the Mandler lately, including landscape. That guy doesn't burn time with lenses that produce crap results.
Jul 24, 2026 at 04:05 PM
p.7 #5Leica 35mm Summicron KOB copy by ‘Mandler’
RustyRus wrote:
They borrowed a famous name and released a lens that looks like an original Leica 35mm Summicron.
Beyond the appearance, it is not particularly impressive, does not render anything like the original, and seems to be relying heavily on the name to sell lenses.
In my opinion, there are far better brands to spend your money on.I understand your opinion, but unless you have tried this lens against the original and had bad results, how can you say "does not render anything like original"?
I own the KOB from Germany and the original KOB from Canada. The Mandler KOB performs just like they do, so what "far better brands to spend your money on" are you referring to?
IMHO, in this case, spending more for the original gets you only a bank account with less funds in it.I’m simply summarizing Bastian’s review. Looking through the sample images he posted, it’s also clear that the lenses don’t have the same maximum aperture. Beyond that, their rendering is noticeably different.
So just out of the gate when copying a lens, you should probably try and get the aperture correct-
Glad you like yours though!!! I am assuming you will be selling your Leica's?
Sorry, I'm quoting your posts in reverse chronological order, but:
Respectfully, does it make sense to argue this passionately against a $300 lens you've never tried but only read about?
Regarding Bastian's review. Did we read the same article? Granted his conclusion is a bit negative, but the rest of the article seems more upbeat. And the images he took with it look wonderful.
https://phillipreeve.net/blog/review-mandler-35mm-2-0-7e/
stgrove wrote
RustyRus wrote
So, in short:They borrowed a famous name and released a lens that looks like an original Leica 35mm Summicron.
Beyond the appearance, it is not particularly impressive, does not render anything like the original, and seems to be relying heavily on the name to sell lenses.
In my opinion, there are far better brands to spend your money on.
I own the KOB from Germany and the original KOB from Canada. The Mandler KOB performs just like they do, so what "far better brands to spend your money on" are you referring to?
IMHO, in this case, spending more for the original gets you only a bank account with less funds in it.
So just out of the gate when copying a lens, you should probably try and get the aperture correct-
Glad you like yours though!!! I am assuming you will be selling your Leica's?
Sorry, I'm quoting your posts in reverse chronological order, but:
Respectfully, does it make sense to argue this passionately against a $300 lens you've never tried but only read about?
Regarding Bastian's review. Did we read the same article? Granted his conclusion is a bit negative, but the rest of the article seems more upbeat. And the images he took with it look wonderful.
https://phillipreeve.net/blog/review-mandler-35mm-2-0-7e/
Jul 24, 2026 at 04:14 PM
p.7 #6Leica 35mm Summicron KOB copy by ‘Mandler’
I think I figured out what Mandler did with the aperture on this lens regarding f/2 versus f/2.4. If you open the aperture to f/2 and use a flashlight to look at the shape made by the open blades, it's not perfectly circular. Did they add a circular mask inside the lens as a fix? It sure just looks like a thin disk inserted in the lens versus a normal lens opening (part of the aperture mechanism?). If so, I wonder if it was designed to be revealed at f/2 but instead it gets revealed at f/2.4. Maybe someone with better knowledge of lens design and access to this lens could confirm or deny.
For what it's worth, anecdotally thus far I see some difference between f/2 and f/2.4: 1.) At f/2.4, I get less of the field curvature that sharpens the corners/long edges when shooting a subject at close distance with a busy background. 2.) f/2.4 is noticeably sharper in the center than f/2 for close distance subjects. and 3.) I get the slightest bit brighter exposure at f/2 but only in a very small center area of the image (or it could be roughly equal light but with slightly brighter center and more vignetting, IDK). In any case, I see almost no disadvantage to shooting the Mandler at f/2.4 for best results.
I've emailed Mandler about this – will report back what they say, if anything.
For what it's worth, anecdotally thus far I see some difference between f/2 and f/2.4: 1.) At f/2.4, I get less of the field curvature that sharpens the corners/long edges when shooting a subject at close distance with a busy background. 2.) f/2.4 is noticeably sharper in the center than f/2 for close distance subjects. and 3.) I get the slightest bit brighter exposure at f/2 but only in a very small center area of the image (or it could be roughly equal light but with slightly brighter center and more vignetting, IDK). In any case, I see almost no disadvantage to shooting the Mandler at f/2.4 for best results.
I've emailed Mandler about this – will report back what they say, if anything.
Jul 25, 2026 at 11:57 AM
p.7 #7Leica 35mm Summicron KOB copy by ‘Mandler’
This lens seems to be creating a lot of controversy. I ordered a copy originally to adapt to my Nikon Zf just to have a tiny lens to carry around for non-critical work. Then I found a deal on a Leica M10-P within 3 days of ordering it, so now the Mandler lives on a Leica. I'm a bit torn on this lens so far. It clearly is not a great lens, but for the price and size, it has its charms. While I'm sure I will end up getting a Voigtlander 35mm f/1.5 or f/1.2 once my bank account heals, for now, I'm enjoying this.
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Jul 26, 2026 at 06:22 AM
p.7 #8Leica 35mm Summicron KOB copy by ‘Mandler’
Getting back to the Ksana vs. Mandler thing after some testing and, importantly, after some real-world experience. Bottom line: I cannot recommend the Ksana at this time, for QC reasons similar to those I've seen complaints about from others.
In terms of general handling, I still largely prefer the Mandler, though after looking at pictures I like the rendering of the Ksana more, so my intention was to keep that one and list the Mandler for sale.
Then I took the Ksana to New York for a week with my M4-P. Everything seemed to go just fine, even if I did find the loose-to-mushy aperture a little frustrating in actual use. No dings, no drops, no damage, and the camera-and-lens combo lived in my overly-padded Billingham when not in use.
When I got home and unpacked, though, I noticed that the aperture ring on the Ksana didn't want to turn past f/2.8 toward f/2. And then I pulled the lens off the camera and, in turning the ring, realized that no matter what I did, the aperture was stuck wide open. It looks like the blade mechanism has somehow become decoupled from the aperture ring. In inspecting that, I also realized that the lens element housing is loose, to the extent that it will visibly wobble around when touched. None of that was the case before I took the thing out for some actual photography.
Had I dropped or bumped the lens or the camera, or were I otherwise able to point to something I did to cause this, that would be one thing. But I can't. This seems to have happened somehow without my noticing during normal use. My best guess is that it has to have happened when I was swapping lens filters around (once or twice they were on there pretty tight and took a little effort to dislodge, though nothing out of the ordinary), but that's just a guess. To make matters worse, it is likely this happened at some point while I was actively shooting without me realizing it, as I was floating around between f/5.6 and f/11 during most of the trip and wouldn't have caught the issues opening up past f/2.8 for that reason. I won't know until I develop the film, but I'm guessing I've got a lot of seriously overexposed images just waiting to be discovered.
I have reached out to Thypoch support to see what they're willing to do about this. To their credit, though the webform I sent generated an autoreply that it could take up to 15 business days to get a response, they emailed in under 24 hours asking for more information and for a video of the problems. I sent that in this morning. We'll see what results, and I'll report back here when I know.
Bottom line, though, is that I would avoid the Ksana 35mm at least for now, even if you like the images. The QC issues are unfortunately very real. My copy will be unusable without repair.
In terms of general handling, I still largely prefer the Mandler, though after looking at pictures I like the rendering of the Ksana more, so my intention was to keep that one and list the Mandler for sale.
Then I took the Ksana to New York for a week with my M4-P. Everything seemed to go just fine, even if I did find the loose-to-mushy aperture a little frustrating in actual use. No dings, no drops, no damage, and the camera-and-lens combo lived in my overly-padded Billingham when not in use.
When I got home and unpacked, though, I noticed that the aperture ring on the Ksana didn't want to turn past f/2.8 toward f/2. And then I pulled the lens off the camera and, in turning the ring, realized that no matter what I did, the aperture was stuck wide open. It looks like the blade mechanism has somehow become decoupled from the aperture ring. In inspecting that, I also realized that the lens element housing is loose, to the extent that it will visibly wobble around when touched. None of that was the case before I took the thing out for some actual photography.
Had I dropped or bumped the lens or the camera, or were I otherwise able to point to something I did to cause this, that would be one thing. But I can't. This seems to have happened somehow without my noticing during normal use. My best guess is that it has to have happened when I was swapping lens filters around (once or twice they were on there pretty tight and took a little effort to dislodge, though nothing out of the ordinary), but that's just a guess. To make matters worse, it is likely this happened at some point while I was actively shooting without me realizing it, as I was floating around between f/5.6 and f/11 during most of the trip and wouldn't have caught the issues opening up past f/2.8 for that reason. I won't know until I develop the film, but I'm guessing I've got a lot of seriously overexposed images just waiting to be discovered.
I have reached out to Thypoch support to see what they're willing to do about this. To their credit, though the webform I sent generated an autoreply that it could take up to 15 business days to get a response, they emailed in under 24 hours asking for more information and for a video of the problems. I sent that in this morning. We'll see what results, and I'll report back here when I know.
Bottom line, though, is that I would avoid the Ksana 35mm at least for now, even if you like the images. The QC issues are unfortunately very real. My copy will be unusable without repair.
Jul 30, 2026 at 08:56 AM
p.7 #9Leica 35mm Summicron KOB copy by ‘Mandler’
Short update to the above. Thypoch responded to my email with a video of the issues with the lens indicating that they will replace it for me at no charge, and that because of international shipping costs I do not need to return the broken copy. Because this lens is presently out of stock, it will likely be the end of the month before the new one arrives. I'll update accordingly once it does.
Though I'm disappointed with the issues with my first copy of this lens, I can't fault Thypoch customer service one bit at this point.
Though I'm disappointed with the issues with my first copy of this lens, I can't fault Thypoch customer service one bit at this point.
Aug 03, 2026 at 09:04 AM
p.7 #10Leica 35mm Summicron KOB copy by ‘Mandler’
randomphotoguy wrote:
This lens seems to be creating a lot of controversy. I ordered a copy originally to adapt to my Nikon Zf just to have a tiny lens to carry around for non-critical work. Then I found a deal on a Leica M10-P within 3 days of ordering it, so now the Mandler lives on a Leica. I'm a bit torn on this lens so far. It clearly is not a great lens, but for the price and size, it has its charms. While I'm sure I will end up getting a Voigtlander 35mm f/1.5 or f/1.2 once my bank account...Show more →
I'm really liking the depth in these photos. I've been really eyeballing the Mandler, but mostly shoot landscape (rural Georgia) and environmental photos of my family. Mind me asking what aperture these were shot at??
This lens seems to be creating a lot of controversy. I ordered a copy originally to adapt to my Nikon Zf just to have a tiny lens to carry around for non-critical work. Then I found a deal on a Leica M10-P within 3 days of ordering it, so now the Mandler lives on a Leica. I'm a bit torn on this lens so far. It clearly is not a great lens, but for the price and size, it has its charms. While I'm sure I will end up getting a Voigtlander 35mm f/1.5 or f/1.2 once my bank account...Show more →
I'm really liking the depth in these photos. I've been really eyeballing the Mandler, but mostly shoot landscape (rural Georgia) and environmental photos of my family. Mind me asking what aperture these were shot at??
Aug 04, 2026 at 11:59 AM
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p.7 #11Leica 35mm Summicron KOB copy by ‘Mandler’
akfujishooter wrote:
randomphotoguy wrote
This lens seems to be creating a lot of controversy. I ordered a copy originally to adapt to my Nikon Zf just to have a tiny lens to carry around for non-critical work. Then I found a deal on a Leica M10-P within 3 days of ordering it, so now the Mandler lives on a Leica. I'm a bit torn on this lens so far. It clearly is not a great lens, but for the price and size, it has its charms. While I'm sure I will end up getting a Voigtlander 35mm f/1.5 or f/1.2 once my bank account heals, for now, I'm enjoying this.https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/07/2026-07-25_17-43-08.jpg
https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/07/2026-07-25_17-01-46.jpg
https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/07/2026-07-25_16-59-57.jpg
Thanks! For the apertures, I want to say,top to bottom, f/4, f/8 and f/5.6. I don't believe any were wide open.
Aug 04, 2026 at 04:30 PM
p.7 #12Leica 35mm Summicron KOB copy by ‘Mandler’
Here are some more shots of the Mandler 35mm f/2 7 element from a county fair I attended a few nights ago.
It's not perfect, but for $348, I'm quite happy with it.
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It's not perfect, but for $348, I'm quite happy with it.
Aug 06, 2026 at 07:33 PM
p.7 #13Leica 35mm Summicron KOB copy by ‘Mandler’
They will release a safari / military version of the 35mm:
https://leicarumors.com/2026/08/22/mandler-will-release-a-new-military-green-safari-version-of-the-35mm-f-2-seven-elements-lens-for-leica-m-mount.aspx/
https://leicarumors.com/2026/08/22/mandler-will-release-a-new-military-green-safari-version-of-the-35mm-f-2-seven-elements-lens-for-leica-m-mount.aspx/
Aug 23, 2026 at 02:26 AM
p.7 #14Leica 35mm Summicron KOB copy by ‘Mandler’
gammarART wrote:
They will release a safari / military version of the 35mm:
https://leicarumors.com/2026/08/22/mandler-will-release-a-new-military-green-safari-version-of-the-35mm-f-2-seven-elements-lens-for-leica-m-mount.aspx/
Well looks like my silver brass will hit the marketplace in the near future lol... especially painful since I paid a premium to a third party to get it before they were shipping outside of China. The green goblin speaks to me...
They will release a safari / military version of the 35mm:
https://leicarumors.com/2026/08/22/mandler-will-release-a-new-military-green-safari-version-of-the-35mm-f-2-seven-elements-lens-for-leica-m-mount.aspx/
Well looks like my silver brass will hit the marketplace in the near future lol... especially painful since I paid a premium to a third party to get it before they were shipping outside of China. The green goblin speaks to me...
Aug 23, 2026 at 02:28 PM
p.7 #15Leica 35mm Summicron KOB copy by ‘Mandler’
endergemini wrote:
gammarART wrote
They will release a safari / military version of the 35mm:https://leicarumors.com/2026/08/22/mandler-will-release-a-new-military-green-safari-version-of-the-35mm-f-2-seven-elements-lens-for-leica-m-mount.aspx/
Keep the silver and just get the green one, too! I’m going to end up with three after I get the green one: brass silver with a Leica 12504 hood, black w/black Mandler aluminum hood, and green.
Aug 28, 2026 at 08:46 PM
p.7 #16Leica 35mm Summicron KOB copy by ‘Mandler’
randomphotoguy wrote:
Here are some more shots of the Mandler 35mm f/2 7 element from a county fair I attended a few nights ago.
https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/08/2026-08-04_20-20-21.jpg
https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/08/2026-08-04_17-36-10.jpg
https://www.jonathanhrovath.com/blog/wp-content/uploads/2026/08/2026-08-04_20-11-47.jpg
It's not perfect, but for $348, I'm quite happy with it.
Nice shots. The colors coming out of this lens are outstanding.
Aug 28, 2026 at 08:48 PM
p.7 #17Leica 35mm Summicron KOB copy by ‘Mandler’
Here is the official response from Mandler tech team regarding the f/2 versus f/2.4 aperture.
Regarding your question about the aperture design, we consulted our technical team and would like to share the following explanation, which we hope will clarify the behavior you observed between f/2.4 and f/2:
The original 7‑element optical formula was derived from the patent of the 35/1.4 “Holy Light.” In practical use, the true maximum geometric aperture of the original design was around f/1.8, but Leica limited it to f/2 using a physical diaphragm. As a result, the aperture shape at the widest setting was not perfectly circular but slightly polygonal.
During our reproduction process, we created two prototype versions:
• one that followed the original design strictly (f/1.8 physically limited to f/2),
• and another with an improved aperture scheme.
The final version you are using has a true wide‑open geometric f‑value of approximately f/2.088, with an entrance pupil diameter of 17.0019 mm. This design provides noticeably better central resolution while preserving the rendering characteristics of the original 7‑element lens. The difference between f/2.088 and f/2.4 is very small, which is why switching from f/2.4 to f/2 may not produce a visible change in brightness. In the original lens, the wide‑open aperture was not fully circular; in our version, we adjusted it to be circular, which naturally results in about a 1/3 EV difference compared with a mathematically ideal f/2.
We have also attached reference images showing the aperture shape of the original Leica Summicron 35mm and our Mandler 35mm at full aperture for comparison.
Another factor that influences transmission is the coating. Our coating is replicated 1:1 from the original 7‑element lens. The original coating was not a modern multi‑layer type, so it had some reflectivity, but this was essential to its color signature. Reproducing this coating faithfully is one of the reasons the Mandler 7‑element lens achieves its characteristic color performance.
Thank you again for your interest in the design. If you have any further questions, we are always happy to assist.
Original Leica aperture at f/2
Mandler aperture at f/2
Regarding your question about the aperture design, we consulted our technical team and would like to share the following explanation, which we hope will clarify the behavior you observed between f/2.4 and f/2:
The original 7‑element optical formula was derived from the patent of the 35/1.4 “Holy Light.” In practical use, the true maximum geometric aperture of the original design was around f/1.8, but Leica limited it to f/2 using a physical diaphragm. As a result, the aperture shape at the widest setting was not perfectly circular but slightly polygonal.
During our reproduction process, we created two prototype versions:
• one that followed the original design strictly (f/1.8 physically limited to f/2),
• and another with an improved aperture scheme.
The final version you are using has a true wide‑open geometric f‑value of approximately f/2.088, with an entrance pupil diameter of 17.0019 mm. This design provides noticeably better central resolution while preserving the rendering characteristics of the original 7‑element lens. The difference between f/2.088 and f/2.4 is very small, which is why switching from f/2.4 to f/2 may not produce a visible change in brightness. In the original lens, the wide‑open aperture was not fully circular; in our version, we adjusted it to be circular, which naturally results in about a 1/3 EV difference compared with a mathematically ideal f/2.
We have also attached reference images showing the aperture shape of the original Leica Summicron 35mm and our Mandler 35mm at full aperture for comparison.
Another factor that influences transmission is the coating. Our coating is replicated 1:1 from the original 7‑element lens. The original coating was not a modern multi‑layer type, so it had some reflectivity, but this was essential to its color signature. Reproducing this coating faithfully is one of the reasons the Mandler 7‑element lens achieves its characteristic color performance.
Thank you again for your interest in the design. If you have any further questions, we are always happy to assist.
Original Leica aperture at f/2
Mandler aperture at f/2
Sep 01, 2026 at 08:01 AM
p.7 #18Leica 35mm Summicron KOB copy by ‘Mandler’
Yes, I remember from the days I had the Summicron (that was back in the 1990s) that the wide-open aperture was not circular.
Sep 01, 2026 at 08:09 AM
p.7 #19Leica 35mm Summicron KOB copy by ‘Mandler’
I have asked them a follow up question, that being it seems that the circular mask is revealed at f/2.4 and not f/2, hence the issue we're seeing. Yes, the difference in f/2.4 and f/2 is small, but I don't think we're seeing any difference in light transmission at all between those two aperture settings. A second question I asked was is this mask removable by a CLA technician. If they say that's possible, I may send mine to DAG to have it removed. But I have a feeling it's part of the aperture mechanism and would require some sort of spacer in there to replace the removed part. I suppose alternatively, DAG might be able to enlarge the opening of the existing mask so that the aperture blades are revealed at f/2.
Sep 01, 2026 at 08:15 AM
p.7 #20Leica 35mm Summicron KOB copy by ‘Mandler’
cabophoto wrote:
Yes, I remember from the days I had the Summicron (that was back in the 1990s) that the wide-open aperture was not circular.
I seem to remember that from the copy I had as well. I think what Mandler is saying is by the time the mask is revealed at f/2.4, we're already getting the same light transmission as the original KOB at f/2. Maybe I'm not reading what they wrote correctly, though.
Yes, I remember from the days I had the Summicron (that was back in the 1990s) that the wide-open aperture was not circular.
I seem to remember that from the copy I had as well. I think what Mandler is saying is by the time the mask is revealed at f/2.4, we're already getting the same light transmission as the original KOB at f/2. Maybe I'm not reading what they wrote correctly, though.
Sep 01, 2026 at 08:21 AM