The company was more recently mixed up in a controversy, because their night vision goggles were supplied to and used by Iran during Saddam Hoessein's reign in 1981. In 1990 they fused with Enraf-Nonius to form Delft Instruments.This Aude Delft Lens
You will not have an easy time to track down this lens, as it’s basically not designed for photographers, so most places show either no or incorrect information about it. In the Allphotolenses' database, for example, it is given a straightforward "large format" flag, which could not be further from reality, as it only draws a much smaller photosensitive surface than APS-C in its basic state. An article about it was published in Petapixel in 2014, but a clear sign of the "deep" "professionalism" of the page is that they didn't particularly follow the subject and took only a few contrast-free, very close-up shots leading to comments that a lens baby is cheaper and better quality.
So we need to make quite a few modifications to be able to use the lens.
Read this about "equivalence" aperture as I estimate this lens to be f0.95 on a 35mm camera. Click Here
The optics of this lens has a total of 8 elements in 5 groups. Built for digital x ray machines some years ago.
The lens does have a screw focusing mechanism, but, its housing is very wide The biggest problem however is that you'll soon realise you can't focus more than 1-2 inches. The problem escalates further if you put it in front of a mirrorless machine, because you will notice that you are far from reaching infinity.
The reason you have a hard time focusing indefinitely is simple: the rear lens element must be less than 1mm away from the sensor / film . At this point, you may feel for a moment that this is why it was written on the net that this lens is really “useless” for the sublime artistic purposes of photography.
So what did I do.
I took off the rear elements and threw them away (well stored them for future use in my future use optics box). Next I made an extra plastic ring on the back of the optics housing that was able to accommodate and hold in place the rear lens section of an SMC Takumar 1.8 / 55. I could rightly expect it to boost a bit in the performance of the optics and Voilà I have a fully working lens!