Every time Nikolas Moldenhauer posts a new Media Division project video on YouTube it’s a time to celebrate and his most recent video might be one of his best yet – creating the fastest lens ever.
Creating the world’s fastest lens
The premise of this entire video (almost a full hour – so grab your popcorn and enjoy) is that there is a way to create a “lens” that can mimic the way an ultra-fast lens looks – faster than any other existing lens ever created.
Before Moldenhauer goes into the specifics of the project he provides an in-depth explanation of the limitations of traditional optics, going back to Stanley Kubrick’s special Zeiss Planar 50mm F0.7 and beyond. Creating any lens that is beyond f/0.7 is not technically possible (and beyond that we are reaching the realm of what a traditional optical lens can achieve even in theory).
So how were Moldenhauer and his associates able to achieve the impossible and go beyond f/0.7?
Fast and Wide
While going the traditional (optical) route would not allow for it, there is a way to “bend” the laws by using a very fast lens (in this case using a Leitz (Leica) Hektor 300mm f/2.8) designed for 6/7 medium format projectors but it covers large format at infinity as well.
While on FF, 300mm is a telephoto focal length, on a (huge) large format it becomes a wide angle (equivalent lens).
One way of “bending the optical laws” is to have the lens project the image on a surface and capture the projected image using a normal 35mm camera. The problem with this simple approach is that to capture the image correctly the camera needs to be placed between the lens and the projected image and get in the way. You can try and use tilt-shift lenses to fix that but this introduces a whole range of other issues.
A different approach altogether (which is the one Moldenhauer chose) was to use what is known as DOF adapter using ground glass. This approach has its problems as well since the glass has a visible structure that can be seen in the recorded image. Hence all sorts of ways were devised to solve this including rotating or vibrating the glass to make the texture of the glass, less visible in the resulting image.
Moldenhauer set out to do this whole concept on a large format 8×10 system. The camera at the end was mounted using its own adapter upside-down to fix the image coming from the lens, but this is just the first step. Focusing needs to be done by changing the distance of the front lens from the projection glass part. You can do that by hand but this will only work for stationary subjects, if you want to shoot a moving subject you are going to need some sort of motorized moving system.
Moving 5.5kg quickly and precisely is not simple. Hence the need for a linear actuator that moves the front lens back and forth accurately (but quite noisy and not super fast).
The ground glass is the next issue that Moldenhauer needed to solve. You need very high-quality glass and even then the edges of the frame with such a large piece of glass will result in a very significant vignette. Adding a fresnel lens before the glass can take care of that but you need a quality one for that as well.
As good as the glass surface that Moldenhauer was able to acquire for this project (manually created for this project by an optical professional) there is still quite a light loss occurring with this setup which gets the original f/2.8 lens to produce actual light transmission of T8 at the other end.
The lens system’s final result is equivalent to an impossible 29mm f0.3 lens – unbelievable and you can see the short beautiful video Moldenhauer was able to capture above and “below” water with this unique setup. Looking at a super fast wide-angle image is really something our brain is not used to.
In the last section of the video Moldenhauer explains exactly how this short video was captured (lots of takes were involved and quite a bit of lighting into the water as well as a special small pool). While this is not a camera system that you are going to use or buy any time soon exploring what can be achieved is always fun to watch but also educational and we can’t wait to see what Moldenhauer will come up with next.
Want to watch more?
You can find more photography-related technology videos in our photo-tech section here on LensVid. You can find more of Moldenhauer videos coverage here on LensVid and we will be sure to bring you more in the future.