The new Trioplan f2.9/50 lens that was announced last week has a new front focusing element which garnered a lot of attention. This innovative front focus lens gives users a second way to focus, and allows nature and macro photographers to take 1:4 images, reducing the minimum focusing distance to 0.28 m from 0.8m. We've interviewed Dr. Wolf-Dieter Prenzel, one of the chief engineers at the original Meyer-Optik company and the company's Chief Technology Officer, to find out more how this new focusing mechanism works and why it lets you get even closer to your subject.

What Makes the Front Focus Element Unique
by Dr. Wolf Dieter Prenzel, Senior Developer of Meyer-Optik (CTO)

When we announced the Trioplan f2.8/50 Kickstarter last week, we were surprised and thrilled to see the excitement around our new front focus element. In today’s world of mass-produced lenses it is indeed a rarity, simply because of the precision needed to manufacture it.

When you move the elements in a lens, you have to guarantee that the optical axis remains the same and intact. This difficult task must be realized in an economically feasible manner. The requirements of centering the optical axis are extremely high, a tolerance of less than 1/100mm. There is little room for forgiveness with this technology.

At the same time, while the design is modern, it is not a completely new concept. The idea of a front focusing element makes use of a principal that was already used by the inventor of the cook triplet, A. W. Taylor.  He made the first theoretical analysis of the associated physical principals of the front focusing element.

During the time in when triplets were in wider use, front focusing elements were also employed by some lens manufacturers, but have been forgotten over time. No documents still exist about exactly when Meyer-Optik used the element on our devices, but to the best of my memory and recollection it was in the 1950s and maybe early 1960s.

In many ways the Trioplan f2.9/50 front focus element borrows from the past by making this technology available again. At the same time, this new iteration is different because it allows for the combination of both the front focusing element and the regular focusing element in one camera lens.  That’s the real advancement and “killer app” of this lens.

How It Works

By using the front focus element, one is moving the first front lens in the tube of the lens. In doing so, one changes the distance of the front lens to the other elements of the optical system. It creates a much smaller distance between the lenses in comparison to moving the main focus element from about 0,8 to 0,28 m. Additionally, it enlarges the image reproduction scale from about 1:8 (original Trioplan 50) to 1:4 (new Trioplan) 50.

This lets the photographer keeps her/his regular 50mm lens with our soap bubble bokeh. But she/he also has got a lens that reaches macro capabilities by using this movable front lens.

Roughly speaking, the photographer gets a result three times as big or he only needs a ninth of the normal movement to achieve that result. This saves the photographer from having to carry a much larger lens if they want near macro performance. It is why our lens is so compact and light.

Photography-wise this opens a whole array of creative opportunities, which otherwise one would need special rings and devices to get the same results. We think being able to carry around this capability on a light lens will empower the spontaneity of the creative process, which photography is all about.

Consider that a front focus element is not just a macro tool, but also that it enhances regular photography opportunities. Together with the soap-bubble-bokeh effect this opens a wider range of possibilities.  

The odd thing with a tool like this is though we know it can do certain things, it will be up to the photographers to define excellence with the element. We’re excited to see what will happen when folks go out and have fun with this lens.

Conclusion

It was great fun to employ this technology on the Trioplan 50 and see the results after we had built the first prototype. It is fascinating to see how these old lenses in combination with today’s technology become an artistic tool in the hands of the photographer.
 
Of course, we’re not done yet. Last year we did started by restoring the Trioplan 100 lens. And now we have this new Trioplan 50 with is front focus lens.  We think of the Trioplan a in  terms of a trilogy. So there needs to be one more lens to complete this series of lenses. But that will be our next new thing for next year.

About Dr. Wolf-Dieter Prenzel

Dr. Prenzel is one of the chief engineers for the original Meyer-Optik company, and one of the world’s leading experts on the Trioplan lens. He is an instrumental part of the Meyer-Optik (http://www.meyer-optik-goerlitz.com/) team in determining the materials and redesign of the new Trioplans. Dr. Prenzel is passionate about design, high-quality lenses and leading edge manufacturing.

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