Angénieux 50mm f/0.95

Analog vs Digital – Angénieux M1 50mm f/0.95

This is one of the most iconic historical lenses (post-WWII), which I know.

I have worked about it in the last two years, because it became available to me physically through foto-friend Thomas.

The facts:

First time I mentioned the „M1“ in my basic essay on Pierre Angénieux here . To date this is only available in German – you will find all the historical facts there:

The 8-lens-Doublegauss was designed since 1953 (patent application) for cine in the different cine-formats in the focal lengths 10mm, 12,5mm, 25mm and finally 50mm and was the first mass-produced lens with aperture <1.

Thomas‘ lens is a unikat item: the historical lens-barrel with aperture ring is integrated into a focussing unit with M58 threaded interface, which allows the adaption to Sony E-mount.

**Fig. 1**: Angénieux M1 50mm f/0.95 in focusing-unit – ultra-slim E-Mount-adapter to M58 on the left – source: fotosaurier

All my findings on the optical performance of this lens measured with Sony A7R4 full-format 62 MP-Sensor you will find here . The lens covers 37mm picture-circle, which is falling a bit short for the need of full-format (43mm) – always remembering, that it is designed for cine „Super35“-format (18.7mm x 24.89mm corresponding to picture-circle 31.2mm).

**Fig. 2**: Angénieux M1 50mm f/0.95 at f/0.95 on Sony FF-Sensor of A7R4 – source: fotosaurier

In addition to the full-format measurements, you will find in the link also the results for the Super35-cine-format, taken with the crop-mode at Sony A7R4 (which has 25 MP resolution in this mode), which is the format it is designed for.

As we know in the meantime, that the resolution of historical lenses in the corners (and also the main picture-area) of the high-resolution sensors may be degraded, I looked for a way to analyse the analog picture on film with the IMATEST-software.

I succeeded with this after nearly two years work – HERE I described the way to do this: taking the pictures of the IMATEST-target on analog film (B&W Agfa APX100) – developing under strictly standardized conditions (Rodinal 1+25, 8′) and generation the digital picture with a film-scanner at 5.000 ppi (reflecta RPS 10M) using multi-scan mode and again strictly standardized sharpening-parameters with SilverFast. This results into ca. 32 MP-pictures at 24mm x 36mm (FF).

The link shows the procedure with a 28mm wideangle Olympus-OM-lens 28mm f/2.8 and unveils essential differences in picture quality in most areas open aperture (with exception of the inner center of the picture).

Now I had to solve the problem, to get the Angénieux M1 50mm-lens focused on film. There is definitely no way, to get the lens via adapter on a 24mmx36mm analog camera. Look at the rear side of the lens in the focusing-unit:

**Fig. 3**: Rear view of the Anénieux M1-50mm f/0.95-lens in the focussing-unit with rear M58mm-thread. The rear lens stands at the level of the M58-thread! – source: fotosaurier

2. Resolution-results on analog film.

What ever you would have constructed, to get this lens adapted onto an M39 or LM-camera body, it would not focus to infinity and not even to the 1,8m-distance, which would be necessary to focus on my IMATEST-target. (I did not take in consideration to use an analog-cine-camera for this purpose, which would of course be fitting to this lens, made for cine35-format … but would have required the use of extensive additional film-equipment and processing systems, which I were not acquainted with!)

I finally did it – read chapter 3 further down, if you are interested how!

Here is the lens transformed into a unikat-combination of Canon7-body and the 50mm f/0.95-lens in focussing-unit. It just allows to focus around the point of 1.84 meters distance to get the IMATEST target sharp:

**Fig. 4**: Angénieux M1 50mm f/0.95 lens adapted on a „stripped-down“ Canon7-body, allowing to focus at 1,8m at farthest … or coser – source: fotosaurier

As there are no focussing aids available (and not even an apropriate finder!) from the side of the camera, the lens has to be focussed, using a ground glass in the waist level finder placed onto the film-plane (with open back!) before the film is loaded. (The good-old Exacta WLF worked excellent for this purpose!)

**Fig. 5**: Focussing the lens on the matte-screen of WLF (Exaktawaist level finder) at open camera befor loading the film – source: fotosaurier

Also the exact framing and adjustment of the film-plane parallel to the target had to be done through the waist-level finder at the open back of the camera.

The adjustment of the film-plane parallel to the camera is one of the most important aspects for precise measurements – especially for the fastest lenses. The depth of focus is extremely narrow at f/0,95 so that sharpness may be given in the focussing location but the film-plane runs out of focus, if it is not precisely parallel to the target.

Using a digicam it is easy to adjust the camera: you take a photo of the target, take this picture out of the camera and analyze it in IMATEST. The software measures the angle between horizontal and vertical lines, which are per definition parallel in the target. That means, the angle should be ZERO, if the camera is perfectly alligned, i.e. the lines are also perfectly PARALLEL on the film-plane.

For a good allignment of the film-plane, I use 0.15° as a limit for the angles between paralell lines in the pictures on sensor or film. In this measurement-session with the Angenieux M1 50mm f/0.95 the values, which I achieved were

0.148° for horizontal lines – 0.004° (= perfect!) for vertical lines.

That used to be sufficient normally. I have, however, to date little experience with apertures of f/0.95 … The horizontal mismatch is within my tolerance, but we will see in the detailed analysis, that there is a important effect in resolution over the picture.

After loading the film, you have to handle the whole set-up like a raw egg, always being aware, that the final digitally converted picture will resolve at 5,08 microns (pixel-size) … and there is a lot of manipulation necessary before each shot:

setting the aperture,
advancing the film,
pre-tensioning the self-timer
pushing the release knob

… and praying, not to stumble over the tripod-legs all the time!

This is the full-frame picture on film:

**Fig. 6**: Full-Frame-Picture Angénieux M1 50mm f/0.95 on Film at f/0.95. Compare with Fig. 2 (on sensor) ! – source: fotosaurier

Even on this small picture at f/0.95, you see already, that the details very close to the edges and corner look sharper than on the Sony-sensor-picture (Fig. 2). Only the very central details show higher contrast on the sensor.

As the lens is designed for the cine35-format it doesn’t make sense to analyze the FullFrame film negative. So I cropped the frame to the width of the Super35 film frame-size in my scanner-preview.

In the following picture you see this situation of the scanned part of the picture. The black rectangle inside the area, which is scanned, shows the size of the super35-frame (24.89mm x 18.70mm) which corresponds to a picture-circle of 31.1mm.

**Fig. 7**: Scanned section of the B&B-negative – the black rectangle shows the size of the super35-film-frame with picture-circle 31.1mm. The whole scanned frame, which is analysed has 34.2mm picture-circle – source: fotosasurier

To enable the automatic resolution-analysis by IMATEST, it is necessary to have the black bars top and bottom of the target. Due to that, the picture area for resolution measurement has a picture circle diameter of 34.2 mm, exceeding the super35-frame by 3.1mm (corner-to-corner).

The following picture shows the set-up for the resolution analysis in IMATESTS. The magenta coloured rectangles mark the contrast-edges at which the resolution is measured – in 44 places all over the picture.

**Fig. 8**: IMATEST analysis set-up for resolution at 44 locations (calles „ROI“), four of which are located in the center (marked by the inner circle), four are located in the far corner areas at ca. 85% of the picture circle. Most of the measurements (36) are belonging to the largest picture-area called here „part way“ – source: fotosaurier

In the next picture you see the individual resolution-values in all these ROIs at f/0.95:

Fig. 9: IMATESTs 44 individual resolution-values (MTF30) within the 34,2mm-picture-circle – source: fotosaurier

The MTF30-mean-values are 1,237 LP/PH for center, for „part way“ (the majority of the picture-area!) mean MTF30 is 560 LP/PH, in the corners it is 378 LP/PH.

In this picture we clearly see, that the MTF30-values at the left side are definitely lower than on the right side edge. Obviously the effect of the small horizontal tilt of the film plane. However, we have to live with that for now, as this was the best allignment, which I achieved during this occasion to measure this lens.

However, the effects on the average resolution readings of this miss-alignment are smaller than it seems on first sight. Due to some field-curvature of the picture plane (which is not an exact plane) the right-edge values are increase, because they moved closer to the best focus, wheras the left edge moved away. I we had a perfect alignment, the right-edge-values would go down and the left-edge-values would increase: as a result of this, the average-values shown in Fig. 11 are not so far from the truth.

The best illustration of the resolution-distribution over the picture is the graph, which IMATEST calls „radial MTF-plot“: it shows the MTF30-value over the distance from the center (in percent!):

**Fig. 10**: The radial MTF-plot for Angénieux M1 50mm f/0.95 at oper aperture f/0.95 on film Agfa APX100 – MTF30 in Linepairs per Picture Height – 100% distance to the center correspondents to 34.2mm picture circle – source: fotosaurier

The software analyses the vertical and the horizontal edges in the target separately. Horizontal values are „mostly“ sagittal and the vertical ones „mostly“ meridional. For both we have very large variations in this graph. This is partly due to the horizontal missmatch of the film-plane, which we have seen already in Fig. 9.

Now let us have a look on the corresponding radial MTF-plot for the digitally taken picture with Sony A7R4 with super35-frame-mode:

**Fig. 10a**: The radial MTF-plot for Angénieux M1 50mm f/0.95 at open aperture f/0.95 on Sony A7R4-sensor – MTF30 in Linepairs per Picture Height – 100% distance to the center correspondents to 31.1mm picture circle – source: fotosaurier

Scattering of measuring points is smaller due to very good parallel allignment of sensor to target (horizontal 0.04°, vertical 0.05°) – but clearly seen is the much lower level of resulution in part way and corners (attention: different scales on vertical MTF30-scale!).

Now we have all bits an pieces together, to show the perfomance of this lens on analog film (Agfa APX100) and on high-resolution sensor (A7R4) in comparison.

This is the resolution of the Angénieux M1 50mm f/0.95 lens at all apertures (0.95 …. 22 – a remarkable span !!) measured on analog film (B&W Agfa APX100) :

Fig 11: MTF30-resolution of Angénieux M1 50mm f/0.95 for all apertures **on analog film APX100 – 22 MP-scan**. Crop from FF-picture is corresponding to a **picture circle of 34.2mm**. Nyquist Frequency of the analog film scans is 2,296 LP/PH (blue line) – source: fotosaurier

Now we can compare the results of this lens measured on the sensor of the Sony A7R4 in Super35-mode, which is restricted to a picture circle of 31.1mm, whereas the analog values in Fig. 11 come from a picture circle of 34.2mm:

Fig. 12: MTF30-resolution of Angénieux M1 50mm f/0.95 for all apertures in **Super35-film-format on Sony A7R4** (NyqFreq 2,080 LP/PH – blue line) – corresponding to a **picture circle of 31.1mm** – source: fotosaurier

Please consider: the green line represents the resolution in a small central picture-area, the yellow lines only the outmost coners (>80% of the picture radius).

The grey curve („part way“) represents the average resolution value of the biggest area of the picture, so it is responsable for the general sharpness impression of a picture.

Though the corners of the pictures taken on the analog film are 1.5mm more distant to the center of the picture, the average corner values at f/0.95 are more than 100% higher than on sensor – which is also similar for the part way resolution-values.

The 10% higher Nyquist-Frequency of the analog-scans does not explain the 20% to 100% higher resolution readings on the analog film pictures. Obviously the lens is not harmonizing with the sensor (inclusive filter-stack and micro-lenses). To me this clearly is an artefact of the sensor.

With my increasing experience with many historical „fast“ or wideangle lenses I can state today, that this is more or less happening with all historical lenses – not only those for rangefinder-cameras. With RF-lenses it is however much more dramatical. There are a few early historical lenses, which do not show these artefacts on sensor. This type of artefacts seems to vanish more and more with focal lengths above 65mm and openings <f/2.0.

The only values, which are higher with the sensor, are the central resolution readings at f/.95 – f/1.4. I have observed that for all fast lenses to date: the center-resolution open aperture is falling back on film compared to digital sensor. I am pretty sure, that this is due to the thickness of the sensitive film-emulsion, which is mostly pretty much thicker than my scan-resolution of 5.08µ – and at f/0.95 the bundles of light-rays hitting the surface of the film may be larger than the scan-pixels. Light diffusion in the emulsion-layer may also have an influence.

At maximum-stop-down with f/16 or f/22 nearly all historical („analog“) lenses show the effect of a dramatical drop of the resolution on sensor – and it is not the normal diffraction limitation. This latter you see on the graph for the resolution on film, where you see a small (ca. 15%) drop of resolution from f/16 to f/22, which may be just diffraction-caused. In the sensor-based measurements, the drop starts in the center behind f/8 and generally behind f/11 – dropping by up to 50% towards f/22. This is seen with many historical lenses on FF-sensor (at least in center resolution). But there are also exceptions.

I will add my analog/digital measurements comparison with the Canon rangefinder lens 50mm f/0.95 as soon as it will be finished.

3. How the „one-purpose-camera“ was built:

I mentioned initially, that the physical rear end of the Angénieux M1 lens barrel has to be brought closer to the film plane than 28 mm. This allows no space for adaptation on the original thread M39 or LM-bayonet.

I stripped down one of my Canon7-bodys to get as close to the film plane as possible:

Fig. 13: Canon7-Camera-body „stripped down“ – M39-lens-flange and front-screws removed to generate a flat surface, which is the closest possible plane to the film-plane – source: fotosaurier

The M39-lens-flange and front-screws removed to generate a flat surface, which is the closest possible plane to the film-plane. I planned to use the screws as a safety-lock to keep the new adapter in place.

As an adapter-ring I bought a step-ring 77-58:

Fig. 14: The new Adapter-ring in place on the Canon7-body with the cut-away for the lightmeter-window. To the right you see the stripped-off M39-flange – source: fotosaurier

The inner female M58-thread on the step-ring allows to thread down the focussing unit with the M1-lens until it touches the surface of the camera body

The step-ring only interfers with the protruding light-meter window – this forced me to make a cut-away on one side of the ring.

Fig. 15: Close view onto the cut-away sevtion on the 77-58 step-ring. You see the M77-male-thread in the cut section, which is not used here. The adapter-ring here seems to „float“ over the camera front. This is the 0,7mm-gap, which the ultra-strong double-adhesive-tape takes, to glue the large flat backside of the step-ring to the flat front of the camera-body.

The step-ring is finally glued with ultra-strong double-adhesive-tape to the flat front of the camera-body – and I could leave the two safety-scews finally away

You see the new „single-purpose-camera“, which is not at all a „point-and-shoot-thing“, because it has to be focussed and framed with a ground glass placed at the back with open back. It focuses at maximum distance to 1,84 meters, which is just matching to image my IMATEST target – or closer of course.

Fig. 16: Final result … single-purpose-camera for a special lens – just remembers me of my Hasselblad SWC, which I used to own in earlier times …

Happy „fotosaurier“, analog picture taken with Angénieux M1 50mm f/0.95 at f/2.8:

Berlin, March 21, 2024

Two crazy lenses of the 1950s – Angénieux 50mm f/0.95 and Carl Zeiss Jena Biotar 50mm f/1.4 for 35mm Cine-Format – plus Canon Lens 50mm f/0.95 from end of 60s

A few weeks ago I was blessed, having an Angénieux 50mm f/0,95-lens and a „Biotar 50mm f/1.4″, at the same time in the same place !

An Angénieux 50mm f/0,95-lens in perfect optical quality and with aperture-mechanism and rehoused into a perfect Sony-E-body, focusing to infinity and ready for measurement in my optical IMATEST-Lab…. this is really a „unicorn“!

**Fig. 1:** Ultra-rare 50mm f/0.95-lens for Cine 35 movie-format – this lens-series (10mm, 25mm and 50mm) founded Pierre Angénieux‘ high reputation in cinematic optics! – source: fotosaurier

The „Biotar 50mm f/1.4″, in great overall condition, which I even did no know about, before I saw it for the first time.

Biotar58f1,4-front_DSCF1765 — **Fig. 2:** One of the best high-speed-lenses ever made in Jena – Biotar 50mm f/1.4 of 1955/56 for Pentaxflex AK-16 cine-camera system – professional performance for professional use! – source: fotosaurier

Photo-friend and co-nerd Thomas handed out both ultra-rare lenses to me for closer optical inspection. I am a happy man!

Fig. 3: Two very rare lenses at the same time in the same place … in my IMATEST-Lab! Sheer happiness! – Source: fotosaurier

Angénieux 50mm f/0,95 (Type M1):

Thomas has proven, that it is possible to re-house the Angénieux-lens for general photographic use with infinity focus:

Fig. 4: The early super-fast Angénieux 50mm f/0.95 lens 0f 1954/55 here in a „Unikat„-version – the basic lens is directly fitted to E-Mount for Sony – source: fotosaurier

Starting in 1953 Pierre Angénieux brought out a series of lenses with f/0.95. In 1953 it was firstly the 25mm f/0.95 (which became the most famous Angénieux lens due to the use in NASA-spaceflights to the moon!) made for cine 16mm format and the 10mm f/0.95 for 8mm-cine.

A few months later he pushed out also a version for 35mm-cine: the 50mm f/0.95 – probably this was in in 1954 – originally in C-Mount. Hartmut Thiele dates this to 1955. It is important to understand, that this is not a lens made for still-photogray amateur use – but Pierre Angénieux showed here all his knowledge dedicated for professional cine-use. He went to the limits of everything, which was possible with glass-types and design- and production-methods at that time!

If you need more information on Pierre Angénieux, please look up my Blog article here!

Following my measurements on the IMATEST-target the picture-circle, that this lens covers is 37mm – so it is falling a bit short from the 43mm needed for covering the still-photo-35mm-full-format (24 x 36 mm).

DSC05014_Ang_50f0,95_0,95-foc1,4_Bildkreis — **Fig. 5**: Picture of IMATEST-Target through **Angénieux 50mm f/0.95 at f/0.95** in the 24 x 36 mm full-frame of the Sony A7R4 – Source: fotosaurier

This test-set-up generates the following resolution-measurement results:

Fig. 6: Resolution at center/part way/corner of Angénieux 50mm f/0.95 on Sony A7R4 (60,2 MP-sensor – 9.504 x 6.336 pixels!) at standard distance full-frame (24×36) – Source: fotosaurier

In spite of the heavy darkening in the corners, the system does still generate results, but these readings are not very reproducible … these corner-readings are located clearly outside the picture-circle for this lens!

So I made a second set-up with the camera set a little bit further away from the target, so that the individual measuring areas move somewhat towards the center of the picture and do not suffer too much from the dark areas out of the picture circle of the lens.

Fig. 7: Angénieux 50mm f/0.95 moved a bit backwards from the target – measurement-areas (marked magenta rectangles) moved somewhat further towards the picture center – avoiding overlap with the dark corners – this picture is at f/8, showing a sharper limit to the dark corner-areas! – source: fotosaurier

Now the furthest measurement locations are at 82% of the full-frame picture radius, clearly inside the bright circle which this lens covers at 86% of full-frame radius!

The result is seen in the following picture:

Fig. 8: Resolution with refocussed Angénieux lens 50mm f/0.95. The corner-resolution-values are still located outside the Cine35-picture-frame!!! The „peak“ at f/4 in the corner reading is real – no error – never seen anything like this with any other lens! – source: fotosaurier.

In Chapter 4 at the end of the article I will ad thwe measuremts at cine-format for all three lenses (Super 35: 18,66mm x 24,89mm). This will give more realistic resolution-readings. The Super35 crop-mode on the A7R4 is 6.240 x 4.160 pixels.

2. Carl Zeiss Jena Biotar 50mm f/1.4:

About the same time, DDR-based Carl Zeiss Jena created a high-speed lens for its own Pentaxflex AK-16 cine-camera system in Pentaflex-16 mount.

It seemed logical to follow the already successfull BIOTAR-formula and it came out around 1955 or 1956 the Biotar 50mm f/1.4:

Biotar58f1,4-2_DSCF1757 — **Fig. 9:** **Carl Zeiss Jena Biotar 50mm f/1.4** for Cine-Format, arriving 1955/56 – Source: fotosaurier

Looked at with the sensor of the Sony A7R4, the picture-circle is a bit larger than with the Angénieux … there are only minimal dark corners!

Bildkreis_DSC05072_Biotar-50f1,4_1,4-just-foc — **Fig. 10**: Full-frame picture of IMATEST-target through Biotar 50mm f/1.4 at f/1.4 – Source: fotosaurier

Of course, we have here the same situation, that the corner-measurements are quite a bit outside the cine-picture frame of typically 16mm x 22mm:

Fig. 11: Biotar 50mm f/1.4 in the same frame as Angénieux seen in Fig. 7 – source: fotosaurier

I will also with this lens repeat the measurement, restricting the resolution-target to the cine-picture frame – see section 4 at the end of the article.

The results show for both lenses, that the resolution in the center is extremely high – even wide-open! Both lenses are extraordinary lenses of their time – the mid-1950s!!!

Unique: „first-in-industry“ point of view for the Angénieux 50mm f/0.95 in its extreme speed, without sacrifycing to the center resolution!

3. Canon Lens 50mm f/0.95 for rangefinder (Canon7) cameras with LTM 39mm – of 1969

As we are just talking about early historical high-speed lenses, the step to the famous CANON 50mm f/0.95 (for rangefinder) is logical. It is a step of 15 years in time – and this time the lens is really dedicated to 35mm still-photo full-format 24mm x 36mm!

Noch'nPaar_DSCF1775 — **Fig. 12**: Angénieux 50mm f/0,95 of 1954, left, and Canon 50mm f/0.95 of 1969 / the normal still-photo-version here – Source: fotosaurier

Here is my comparable resolution-measurement with two samples of (s.n.18924 and s.n.22372) of the Canon 50mm f/0.95 on Sony A7R4 for this lens at full 24×36-format:

Crf_50f0,95_Graph — **Fig. 13**: Resolution-Graph of **Canon 50mm f/0.95** on Sony A7R4 (60,2 MP) – Source: fotosaurier

Fig. 13a: Resolution-Graph of Canon 50mm f/0.95 on Sony A7R4 (60,2 MP) – Source: fotosaurier

To allow for the necessary rangefinder-coupling besides the huge rear lens, this lens is „cut free“ at the edge for this purpose.

Crf59f0.95_DSCF1687 — **Fig. 14**: Cut-away at the 50f/0.95 Canon’s rear lens, to allow for the rangefinder-coupling! – source: fotosaurier

However, the 50mm f/0.95 lens was also released in a version for video cameras, with an additional engravure „TV“ on the nameplate: consequently these lenses were delivered with C-mount. As these lenses do not need the rangefinder-coupling, the rear lens is not cut at the edge here:

Thank you, foto-friend Thomas, for the 50mm f/0.95 TV-lens rear section photo.

4. Finally: Resolution-Data of these Lenses, measured for the Cine Super35-format, which the Angénieux and CZJ Biotar Lenses are originally dedicated to – on all three lenses:

a) Angénieux 50mm f/0.95 – at Super35-format:

Fig. 16: Angénieux 50mm f/0.95 at Super35-frame on Sony A7R4 – absolutely phantastic for this „first-in-speed“ – source: fotosaurier

b) Biotar 50mm f/1.4 – at Super35-format:

Fig. 17: CZJ Biotar 50mm f/1.4 at Super35-frame on Sony A7R4 – absolutely phantastic at one stop slower – source: fotosaurier

c) Canon 50mm f/0.95 – at Super35-format on Sony A7R4:

Canon lens f=50 mm f:0.95_A7R4_Super35_Graph — **Fig. 18**: **Canon Rangefinder 50mm f/0.95** – primarily dedicated to still-photo 24×36 but also delivered as a TV-version – just a bit better than the Angenieux, but 15 years later! – source: fotosaurier

All three lenses have very low chromatic aberrations in the center but the Canon peaks out in maximum CA, Biotar and Canon are close to zero in distortion, while the Angenieux has around -1% distortion, which is still excellent for such an early, extreme lens!

5. Appendix:

Here you see all properties of the three lenses in detail – for 24×36 (full frame) and Super 35 (cine-format).

5-a1. Angenieux M1 50mm f/0.95 – FullFormat 24×36.