Voightlander Lenses, LoCa and Purple Fringing

[LarsHP]

Advertisement (gone after registration)

2 hours ago, Alan Friedman said:

Here is a look at the level of apochromatic correction of my copy of the VM Apo-Lanthar 35 at f2. This image is a cropped jpeg at 100%, using a macro M-L adapter on the Sigma fp to bring close focus to within 10" of the ruler. Click to open the full size file. The camera is hand held at 1/60 to avoid banding from the LED lighting in my office. Looking at the words, one can see a faint green hue beyond focus and purple in front of focus... but close enough for government work, in my opinion.

This is a stellar LoCa performance in my book. The 90mm Apo-Summicron-M is not half as good as this - if fact, while it's very sharp, I only consider it semi-apochromatic.

On another note, it's worth mentioning that the "apo" designation is brand-related. For instance, Nikon don't use that term about their lenses even though some Nikkors are at least as apochromatic as the 90mm Apo-Summicron-M - for instance the AF-S Nikkor 200mm f/2 VR / VRII and Z 85mm f/1.8 S. Sigma has worn out the designation in their EX series even though some of their "apo" EX lenses (macros) are impressive. They probably realized this and changed their top of the line series to "Art" instead of EX Apo etc.

Edited March 29, 2021 by LarsHP
added link

[Alan Friedman]

2 hours ago, paulcurtis said:

Yes, that's pretty good. As you say i can see both the green and purple. Shame you don't have a Leica to compare with! And shame the MFD isn't the same as the E mount version (35cm) i think the VM is 50cm?

I look forward to seeing how the lens performs and if it matches the 50 well!

cheers
Paul

Hi Paul... I do of course have Leica bodies as well but my M cameras are older pre-live view models. I believe the sensor stack in the SL(601) is close to the Sigma fp. Have to admit that since acquiring the Sigma fp I use it much more frequently than the SL. That said, and qualified by the fact that I rarely do this sort of technical testing, I lean more to LarsHP in my appreciation for this result. This example was shot at the closest focus possible using the macro adapter - bringing the MFD to approximately 25cm - much closer than the designers anticipated when creating this lens (the A-L 35 is 50cm MFD). 

My main experience with apochromatic optics is with telescope design. I've been fortunate to own and use some very exotic hand made lens sets from Zeiss and Astro-Physics which utilize calcium fluorite and hand polished aspherical surfaces that, with interferometer testing during the polishing process, attempt to bring as much starlight energy as possible into the center of a star's in-focus diffraction image. Out of focus performance is not a thing in this world. I'm guessing that the goal in the Apo-Lanthar lens series is similar - to bring as many wavelengths of visible light as possible to the same focal plane. What happens intra and extra-focal appears very good though it does show subtle CA tonality in a test image such as this where everything is virtually monochromatic. I mounted the lens yesterday for the first time and took a few hundred exposures in my shop. I will post a few additional real life examples in a bit. I'd also like to try this color fringe test with the A-L 50 and contrast with my APO Macro-Elmarit-R 100, which has always seemed a remarkable performer to my eye. Such testing is not particularly meaningful in making good pictures, but it sure is fun to look at and talk about. ;^)

As mentioned above, I am a big fan of the Sigma fp and am interested to see what might be possible for still shooting with the new 61mp model using sensor cropping with a lens of this sharpness and clarity. 

best wishes,

Alan

 

 

Edited March 29, 2021 by Alan Friedman

[paulcurtis]

2 minutes ago, Alan Friedman said:

As mentioned above, I am a big fan of the Sigma fp and am interested to see what might be possible for still shooting with the new 61mp model using sensor cropping with a lens of this sharpness and clarity. 

 

I really appreciate the images and details.

Yes i have an fp as well which i find myself using all the time. I'm unsure about the L upgrade though and one of the reasons is that being an electronic shutter the 61mp sensor is even slower to read out and even in stills this will lead to distortion on longish lenses. I think this is an area a lot of people aren't talking about but if you hand hold a portrait on a 90 cron and fire off a bunch of shots - you can see the skew and wobble from still to still because of the handholding, On a single image you can't tell but shoot a bunch and flip between them - it's crazy obvious. Of course hand hold and wobble just in the right way and you can make someone taller, shorter, thinner or larger!

I used the fp for some video work too which ended up costing me more time because of the rolling shutter but even so it is a fantastically small and capable camera. And i look forward to getting the new EVF to use with the original cam (I hope it works!)

I've always wanted to get into astrophotography but i've held off because my office physically cannot fit any more 'stuff' in it...

cheers
Paul

[BrianS]

APO - short for Apochromatic, is a technical term- not owned by a brand. Kind of like calling computer application code an "app". I always prefer calling it "code".

Apochromatic simply means that three distinct wavelengths of light are brought into focus in the same plane. Ultra-Achromat, four wavelengths of light are brought into focus in the same plane. The designation does not include the walk-off for other wavelengths. An Achromat with very slow walk-off can out-perform an APO lens. Nor does it specify what wavelengths are selected for correction. The UV-APO lens I have is corrected for UV, but not IR. It transmits IR - it uses Calcium Fluorite optics. The Pentax 85/4.5 Ultra-Achromat is corrected for UV, Visible, and IR. Lessons I remember from the Optical Engineer that worked for me. Always worth sitting down with him on a break.

Edited March 29, 2021 by BrianS

[Alan Friedman]

23 minutes ago, paulcurtis said:

 

Yes i have an fp as well which i find myself using all the time. I'm unsure about the L upgrade though and one of the reasons is that being an electronic shutter the 61mp sensor is even slower to read out and even in stills this will lead to distortion on longish lenses. I think this is an area a lot of people aren't talking about but if you hand hold a portrait on a 90 cron and fire off a bunch of shots - you can see the skew and wobble from still to still because of the handholding, On a single image you can't tell but shoot a bunch and flip between them - it's crazy obvious. Of course hand hold and wobble just in the right way and you can make someone taller, shorter, thinner or larger!

 

Concerned about this as well, but I have been very impressed with Sigma products since the fp was released, I'm encouraged to give it a try. Thinking it wouldn't be bad to have two bodies with identical interface but slightly different personalities. And I get $200 off the new one by buying that EVF which I would have gotten separately at any price to fill that hole in the original camera. 

According to my family, telescopes take up a lot more room than cameras.

;^)

[Alan Friedman]

Here is a set of examples captured with the VM Apo-Lanthar 35 through a dirty window in my production shop. I don't think the hundred year old window glass is a helpful addition to the lens design, but even with it, there is precious little false color visible. A couple of full size crops converted from DNG to JPG below.

 

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

[Ko.Fe.]

Advertisement (gone after registration)

The only CV lens I noticed PF was first Nokton 50 1.5 VM version. It was noticeable wide open. But it was great BW lens on M-E 220 and M4-2. 

Cheap CV CV 35 2.5 was as good as Summarit-M 35 2.5 on digital. And 21/4 isn't shoving something noticeable. Can't find it to be bad with 35 1.4 II, either.

Didn't noticed LoCa with any of those. 

CV made very many RF lenses, probably more than Leica did. Some lenses have many versions just as Leica has. Maybe some of those lenses are with more FG and LoCa.

 

[Ko.Fe.]

On 3/26/2021 at 1:48 PM, BrianS said:

If you have an M9 or M Monochrom, use a UV filter. At least Test the lens and camera combination before making general assumptions.

 

Leica M9, Voigtlander Nokton 50mm F1.5 V2, Multi-coated version, wide-open. Same lamp as used with the M8.

No Filter, B&W UV/IR Cut Filter, and B&W UV/IR Cut Filter AND a second UV multicoated filter.

I have a number of lenses used with the M9 and M Monochrom with UV/IR cut filters on them. I've done tests of purple fringing before.

On the plus side: I can use the M9 and M Monochrom for UV photography and they cost a lot less than other cameras for this intended purpose.

 

The color rendering is nothing like the eye picks up. The M8- far less UV sensitivity. The M9- "Gee, Leica should have given away two free UV filters with each one sold"... M8 owners will get the reference. 

 

Cool- I get a free UV capability that's better than I hoped for.

 

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Interesting observation. I don't understand what is on photos. But I trust your words. Is UV filter enough on M9 sensor or it has to be IR?

[BrianS]

The purple fringing seems to be mostly from UV light- I think the UV filter does most of the work to eliminate it.

I have also tested the M9 with IR sources- there is some leakage, but nothing like I see with the UV lamp.

[Alan Friedman]

A few sample images posted to a related thread:

 

[paulcurtis]

On 3/29/2021 at 9:54 PM, Alan Friedman said:

A few sample images posted to a related thread:

Thanks Alan, some lovely images in there. Also i saw your sun photos from your website and they are stunning, very inspiring.

I bit the bullet and ordered a CV 50 APO myself and will see how it works for me. 

I have some new cine APOs arriving in the next few weeks as well, so once i have the collection i will attempt to do a @Harpomatic style review (can't promise that level of detail) but i will be able to compare:

50 cron, 50 canon 1.2 RF, CV 50 APO, 50 APO HyperPrime, 50 zeiss contax, 50 OM Macro f2, 50 FD and this new APO cinelens. I may also be able to get my hands on some other 50s as well.

cheers
Paul

[LarsHP]

Please post (a link to) your results here, thanks! 😇

[Alan Friedman]

14 hours ago, paulcurtis said:

Thanks Alan, some lovely images in there. Also i saw your sun photos from your website and they are stunning, very inspiring.

I bit the bullet and ordered a CV 50 APO myself and will see how it works for me. 

I have some new cine APOs arriving in the next few weeks as well, so once i have the collection i will attempt to do a @Harpomatic style review (can't promise that level of detail) but i will be able to compare:

50 cron, 50 canon 1.2 RF, CV 50 APO, 50 APO HyperPrime, 50 zeiss contax, 50 OM Macro f2, 50 FD and this new APO cinelens. I may also be able to get my hands on some other 50s as well.

cheers
Paul

Cool beans... I look forward to reading your thoughts. 

And thanks for the kind words on my sun images. Mostly all of my experience with apochromatic optics comes from my use of telescopes and I've been fortunate to own some wonderful highly corrected instruments. I haven't bought a new telescope in many years... (about twenty) and the cameras I use are also a decade old. I have a filter that I have to keep in front of my optical train that limits what I can't do and I can't do much about it - the atmosphere. The jet stream is pretty much parked on top of Buffalo all the time - moments of steady air and stable images are few and far between. I know that this is my biggest limitation by far. I haven't yet reached the limits of what my optics can accomplish so I really don't feel the need to update my gear. 

Now terrestrial cameras and lenses, that is a horse of a different chroma!