Exciting update on the lens design.
This just in from our Lens designer Jason Lane in the US.
Alfie TYCH + Premium Lens is no longer a 2 element periscopic lens design, it’s getting a major upgrade!
Here’s a summary of what the lens upgrade means
The Alfie TYCH+ Comes with a premium 33mm F8 glass lens.
Designed around a classic Aplanat or Rapid Rectilinear design with 4 Elements in 2 groups. A modern higher index, lower dispersion glass replaces the two outer glass-types, and helps to correct over the wider spectral range (400-700nm) required for modern photography. A single-layer anti-reflection coating on all optical surfaces provides a balance of high transmission with a classic ever-so-slightly warm colour rendering.
And for those of you that love the detail here is the full design notes.
The Premium TYCH Lens is a nice little performer which represents the practical balance of cost and quality that modern American optical designers and design teams produce today. Worked out over the course of July-August 2022, the simplicity of the layout belies the challenges of space constraints and desired price point that the lens had to meet.
This design consists of 4 elements in two groups, with front and rear groups being the exact same doublet. The layout appears to be that of a classic Aplanat or Rapid Rectilinear, but the design corrects more like a 6/2 Double Anastigmat. A modern higher index, lower dispersion glass replaces the two outer glass-types of the classic D.A., and helps to correct over the wider spectral range (400-700nm) required for modern photography.
Design symmetry corrects distortion, coma, and lateral colour. The shape, position relative to the stop, and thickness of the lenses help correct spherical aberration, astigmatism, and field curvature. Limiting the aperture stop to f/8 also helps spherical aberration and field curvature, and provides acceptable depth of focus over a wide range of object distances as well as helping to balance higher order residual aberrations against the third order.
A single-layer anti-reflection coating on all optical surfaces provides a balance of high transmission with a classic ever-so-slightly warm color rendering. Applied using modern deposition equipment in a state-of-the-art optical shop, the surfaces will stand up to cleaning methods as commonly practiced by the equipment-conscious modern film photographer.
Focal Length 33.3 mm (50mm equivalent on half frame)
f/# 8.0 at street photography distances 7.7 at infinity
Field of view (half frame; 24 x 18 mm) 40° x 30.55°
Corrected spectral range 400-700 nm
We’ve got to make some shutter mounting adjustments to help minimise vignette with the lens, things are looking pretty good on paper even without the tweaks we want to make. Once the prototypes are in we’ll be excited to share some images with you all. It’s a 6-8 week lead time on prototype optics, but with this upgrade the wait should definitely be worth it.