(Reverse-)Mounting Schneider Componon-S 50 mm on C/CS-Mount

It is tempting to obtain one of these precision sliding tables, but I am strictly trying to stay on a budget, so will try to be creative.

I suck in 3D CAD and don’t have a 3D printer either, so sketched something together with a pencil and it will be based on simple MDF plates and screws:

Raspi Cam, Extension and lens on top (tripod screw on the left not drawn yet). The C-Mount Adaptor has a 54 mm diameter and fits perfect into a pipe clamp from the hardware store. It is mounted with a M8 screw with the 22mm “brick” underneath. This screw and the 1/4" UNC 20 tripod screw shall alow me to level the optical part perfectly, lock nuts should hold it in level.
The batch of MDF plates is supposed to bring the optics on to projector gate level. Also, for Z- and X-Axis adjustments, there will be two knobbed screws going into drive nuts, fixable with lock nuts. The MDF plates are sliding between 10x10x2mm aluminium profiles.

Let’s see how this holds up. Cross your fingers :slight_smile:


Looking forward to seeing how this works out!

I was looking into buying a very similar (albeit cheaper) chinese camera with a similar sensor (the cheaper version of the IMX252, the IMX265) so I looked up the lens you bought. In the leaflet they are described as only being 2MP lenses (https://www.tamron.biz/en/data/fa/pdf/leaflet/E_EE008_009_FR.pdf) and for sensors up to 1/1.8". So according to Tamron the lens should not have a sufficient optical resolution to handle the 3.45µm pitch of this sensor. I think the new Pictor from Filmfabriek is using the same sensor btw, although this machine only scans 8mm formats (as far as I know). They are using this lens F1.8/35mm - Ricoh International B.V. together with 30mm worth of extension tubes. This lens has an optical resolution high enough to handle the 3.45µm pixel pitch, and without extension tube is able to focus on 35mm film.

1 Like

The Ricoh lens sounds like an interesting option for something like Kinograph, where you might ship the machine to people and using new components is the right thing to do. It certainly beats the Schneider in price (new) at about 600€ vs. 900€ (just a quick Google search). Only needing extension tubes would also make for a simpler setup than adapting the Schneider lens.

The Tamron lens @matthewepler bought would probably be enough for most 1080p scans, though. At 180$ new it is obviously much cheaper than both the Schneider and the Ricoh. But for 4K scans I think you need something sharper, such as the Ricoh or the Schneider.

That said, I think the used price of the Schneider (and other enlarger lenses) at 50€ to 100€ is hard to beat and probably the preferable option when putting together a scanner for yourself. Even the cheap (but also much worse) lenses you can buy for the Raspberry Pi HQ Camera cost almost as much.

1 Like

I was mostly wondering how true the specs are, meaning how bad will a ‘2MP’ lens perform and does this lens really have a 1/1,8" image circle. Meaning that with the IMX252/265 being a 1/1.7" sensor you will have dark areas at the edges etc. Btw these Fujicon lenses are also good options for that particular sensor: http://mvlens.fujifilm.com/en/product/hf12m.html#anc04

I agree for diy projects the lenses you already own or can find used are hard to beat, I am planning to use a Canon MP-E 65mm that we already own. This macro lens is also used in the MWA Flashcan Nova in combination with a C-mount camera. With something that looks like a 12mm Canon extension tube for some reason. As shown here: https://mwarest.mamory.net/media/c462a1.jpg?t=p&mk=1594827672125

Thanks for the info regarding the setup. After experimenting with the Pi 16mm lens I decided to upgrade my system to the Componon. Just waiting for the components to arrive (kerching, not spending any more !.) Also had to reprint and rearrange several parts of my system to give me more distance for the setup. I had a few issues trying to get full res using basic python code but would be interested to to see your (or anyone else’s for that matter !) code for comparison.

Hi !

Just a link to Jose in Portugal who can built everything you need, I’ve just received an C-Mount / 40.5 adaptator, it’s perfect.





For the python code you can look at my github project:


Unfortunately, I don’t have any Python code yet because my own project has been progressing rather slowly lately (as life gets in the way … I’m sure many here are all too familiar with the phenomenon :smiley:).

I’m glad to see @dgalland has shared his code already. Maybe the question generally warrants a one-place-to-go-to thread where people can link and discuss Python code they use for capturing frames (much in the same spirit as the Scan Examples of Super-8 material thread)? It might allow others (myself included when I finally get there :smiley:) to find information on the topic in one place.

P.S. The photos from my experiment above were taken using the raspistill command. You could, in theory, call this from a Python script … but please don’t! :wink:

I am in the process of modifying my device to use the Raspberry Pi HQ camera together with a quality lens.

For this I have relied on the @jankaiser optical system. Thanks for sharing.

My old lens had a focus ring. The new lens is Rodenstock Rodagon and it does not have such a focus ring, you have to focus by varying the distance between the lens and the film frame, so I have to devise a positioning system for the optical assembly in the xyz axes.

I also had to adapt the software to change the old Raspicam V1 camera for the new HQ camera.

I leave some photos of the current state.

My new optical system and camera. From left to right: Rodenstock Rodagon 50mm f 1: 2.8 lens - M39 to M42 adapter ring (not seen in photo) - M42 helix ring, 17 to 31mm extension - M42 28mm fixed extension ring - M42 Adapter to C Mount - C to CS Adapter Ring - Raspberry Pi HQ Camera.

Assembly that I have made to test the new system, photographing graph paper.

Image obtained from graph paper about 77 mm away from the lens. As you can see, with an image of approximately 6x5 mm, the entire camera sensor fills up. I think it’s a very good raise. A Super8 frame measures 5.7x4.2mm. There is enough space for the frame and some margin in the surroundings.



OMG - Thank you - thank you - something that is not made of chinesium - will hopefully solve my mounting issues.

1 Like

I’m returning to this thread because my initial tests with the lens I bought showed some distortion and the focal length did not fill the frame with the image on the film. :\ Lucky for me you all know so much about this stuff and can guide me to a better solution. I love this community!

I have a couple of questions…

Is there is any advantage to having the extension tubes in C-mount size or the M42 size. Any considerations there? I see that @jankaiser is using M42 tubes and @peaceman is using the C-mount size.

Secondly, do users that have the helical tube find that its adjustment is fine enough to make this possible? And does it stay in focus when in operation? I’m worried the vibration of the machine will cause it to go out of focus .

I don’t think there is any particular advantage to using either size extension tubes other than availability and price of course.

Regarding the focusing, I find that I’m never using the helical (builtin one on the Raspberry Pi camera in my case). Instead I’m using a macro focusing slider to get the film in focus and I know that the framing of my otherwise constant lens setup will be fine once I have set the focus.
The slider im using doesn’t have any set screws, but it still doesn’t move out of focus during scanning, even though the whole thing is currently placed on a very shaky table :smile:. I have the camera mounted horizontally, though, so I don’t know if this would be the same in a vertical setup.

I hope this helps!

1 Like

That does help, thank you @jankaiser. Regarding the slider for focusing, I’ve bought a few different kinds and mostly they’re the dovetail type meant for DSLRs. I did, however, just get this microscope 2-axis piece in yesterday and will try that as well.

Regarding the first question, optically I think there is no difference between the 42mm adapters and the C mount adapters.

The use of one type or another would be determined by availability and price, although in my opinion, mechanically and aesthetically, 42 mm adapters are better.

As for the second, in my assembly I do use a helical adapter with a variable extension between 17 and 31 mm. All my adapters are inexpensive, Chinese in origin, but of pretty good quality.

Specifically, the helical adapter works very smoothly, without harshness throughout its travel.

With this optical system I have recently digitized two complete reels of 120 m each without problems.
Once the focus was adjusted, I didn’t have to retouch it at any time.

It is true that the mechanical operation of my machine is very smooth. In my opinion, to avoid vibrations, it is essential to adjust the stepper motor to operate at very high resolution, with small microsteps. In my device I use 32 microsteps per step, 6400 microsteps per revolution, in this way the vibrations are minimal.

I take this opportunity to comment that the final assembly of my optical system is not the one that appears above in this same thread, but rather the one that appears in this other thread https://forums.kinograph.cc/t/my-telecine-machine/ 2054/9.

The reason for the change is the impossibility of focusing with the first montage.

If observed, with the first mount the distance between the lens and the sensor varies, but the distance between the lens and the film also varies, which prevents focus.

With the final mounting, the distance between the lens and the film remains constant, only the lens - sensor distance changes and with the helical adapter it is focused with great ease and precision.


1 Like

I have to agree with @Manuel_Angel that the M42 solution looks a lot better. That said, M42 is really only chosen for convenience because of the availability of M42 components. Ideally, one would want to go straight from C-Mount to M39 (if you are using a Componon-S or similar). M39 components are not quite as easily found, though.

1 Like

Another vote for using the M42 heli. I also have a c mount version, but it’s a lot stiffer to move with less range. The Unifoc12 made by Schneider Kreuznach is very nice, and has a thumbscrew for locking. But it’s very expensive unless found 2nd hand on eBay. I use the cheap 36-90mm generic version on eBay as I can pull out for 16mm, and also punch in for 8mm. I haven’t noticed any vibration changing it.

Thanks for the guidance, everyone. I ordered a variety of parts to try out and should have all of them by next week. I will post tests on the social media pages and the results will be in the monthly update. You all saved me hours of research.

Maybe someone here can give me some insight into something I’m observing with my lens setup, and that others might be seeing as well.

Depending on the aperture I’m setting on the 50mm Componon-S, I’m seeing substantial changes in sharpness, to the point where f4.7 is perfectly sharp, but f16 is notably lacking in sharpness. This is in line with this test on the 50mm Componon-S that states that the lens is sharpest at f4.7.

I think I remember @cpixip mentioning in one of his posts that mounting the lens this far away from the sensor is taking it somewhat out of its design working range. I imagine then that in this case the strong difference in sharpness is the result of the rather strong magnification which simply makes the difference in sharpness that much more visible? I’m assuming others are seeing the same effect with other lenses in similar setups?

@jankaiser: well, what you have observed is a general behaviour of normal optical systems. It’s pure physics and engineering.

Basically, any lens will underperform with the aperture wide open. The reason is that even today most optics are based on spherical lenses. They are easy to manufacture.

However, a spherical lens is a good approximation to a perfect lens only close to the optical axis. Lightrays which pass noticably off-center do “notice” the deviation between the spherical surface one can manufacture and the theoretically optimal lens shape. The image gets blurry.

The simple solution: one closes the aperature, which cuts off these “bad” off-axis rays. The image gets sharper.

However, there is another challenge hiding here: optics are usually calculated based on the assumption of light propagating along straight lines (“light rays”), getting bend appropriately by the curved surfaces of the lenses. In reality, light is an electromagnetical wave. And that means (among other things) that light gets bended around sharp corners or tiny holes located in its propagating path. This results in the so-called Airy disk phenomenon: the further you close an aperature, the larger the Airy disks of that lens gets. Or, to word it differently, the image gets blurry with smaller aperatures.

Now, as both effects are at work simultaniously, it is clear that for every lens there exists an optimal f-stop where you get the most out of the lens. For the Schneider Componon-S, this range is around 4,7-5,6.

Actually, nowadays one is able manufacture not only spherical, but also aspherical or even freeform optical surfaces, mostly by using single point diamond turing machines. Lenses produced by these means are performing better even with wide open aperatures. However, most lenses today are still based on spherical optics and feature one or two aspheric lens elements at most.

In the Super-8/Raspi HQ camera setting, the Schneider Componon-S 50mm is operating quite close to a 1:1 mapping (distance between gate and lens = distance between lens and sensor = about 100 mm), and that is actually within the design range of this lens.