







I stumbled across a broken Sigma 45mm f/2.8 Art lens for a very cool $58.65 USD that I simply could not resist. I've been eyeing an AF lens in the 50mm range for my recent endeavors with L-mount cameras and this looked like the perfect fit. This lens is commonly found as a kit with the very excellent full-frame Sigma FP camera series. Here is my comprehensive guide to bringing the lens back into service. I delve into the nitty-gritty details of lens PCB repair and lens disassembly techniques.

Louis Rossmann
Limits and Colimits in a Category of Lenses
Lenses are an important tool in applied category theory. While individual lenses have been widely used in applications, many of the mathematical properties of the corresponding categories of lenses have remained unknown. In this paper, we study the category of small categories and asymmetric delta lenses, and prove that it has several good exactness properties. These properties include the existence of certain limits and colimits, as well as so-called imported limits, such as imported products and imported pullbacks, which have arisen previously in applications. The category is also shown to be extensive, and it has an image factorisation system.

Project Cambria: Translate your data with lenses
Changing schemas in distributed software is hard. Could adopting bidirectional lenses help?

Symmetric lenses | Proceedings of the 38th annual ACM SIGPLAN-SIGACT symposium on Principles of programming languages
A lens is a bidirectional transformation between a pair of connected data structures, capable of translating an edit on one structure into an appropriate edit on the other. Many varieties of lenses have been studied, but none, to date, has offered a ...

Microscopes can See Video on a LaserDisc - Andonstar AD246S-P
NONS SL660
Shipped within 4 working days. * 1 year warranty for all our camera products. NONS SL660 An interchangeable-lens SLR instant film camera that works with Fujifilm instax Square Film. Native EF mount SL660 is a passive EF mount camera, fully compatible with EF lens, and various vintage lenses of M42, Nikon F, PK, C

Solarpunk Is Gen Z's Future
A Review of the Ray-ban Meta AI Glasses for People With Low Vision
In the small group of professional certified vision rehabilitation therapists (CVRT), to which I belong, it is not uncommon for us to use the term “magic glasses.” These are the glasses some of our clients hope to find that will improve or restore their vision. It makes sense—in that for many of them, a new prescription once brought things back into focus. Vision loss from macular degeneration, glaucoma, diabetes, and other conditions is usually something that can be managed with proper care, but vision is not typically restored to what it once was. Still, the myth or hope for the magic glasses persists.

Quotient lenses | Proceedings of the 13th ACM SIGPLAN international conference on Functional programming
Bidirectional programming languages are a practical approach to the view update problem. Programs in these languages, called lenses, define both a view and an update policy - i.e., every program can be read as a function mapping sources to views as well ...

Delta Lenses over Inductive Types
Existing bidirectional languages are either state-based or operation-based, depending on whether they represent updates as mere states or as sequences of edit operations.In-between both worlds are delta-based frameworks, where updates are represented using alignment relationships between states.In this paper, we formalize delta lenses over inductive types using dependent type theory and develop a point-free delta lens language with an explicit separation of shape and data.In contrast with the already known issue of data alignment, we identify the new problem of shape alignment and solve it by lifting standard recursion patterns such as folds and unfolds to delta lenses that use alignment to infer meaningful shape updates.
VITURE Luma Ultra XR/AR Glasses
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#FP4Party Series 4. Ironwork. 📷Minolta α-9 🔘Minolta AF 28mm f/2 and Sony 50mm f/1.4 🎞️Ilford FP4+ 📍Brussels, Belgium #filmphotography #believeinfilm