The Complete Handbook of Lens Converters
A practical reference for photographers, filmmakers, and optical engineers on selecting, using, and maintaining teleconverters, wide-angle adapters, and macro couplers.
by Alumigogo Books
non-fiction
The neutral, technical reference on teleconverters, wide adapters, and macro couplers: how they work, what specs matter, and how to use them well.
About this book
Lens converters are the most misunderstood accessories in photography and cinematography. A 2x teleconverter can double your reach, but it also changes the effective aperture, degrades resolution at the edges, and slows autofocus. A wide-angle adapter can turn a kit lens into an ultrawide, but it introduces distortion and chromatic aberration that vary with the lens you mount it on. This handbook treats those trade-offs as engineering facts to be measured and managed, not problems to be ignored.
The Complete Handbook of Lens Converters walks you through the real optical mechanics: how focal length multipliers work, why image circle and flange distance matter, what coatings actually do, and how to read the MTF charts that matter. It provides a practical decision framework for matching a converter to a specific lens and camera body, with worked examples for common combinations like a 70-200mm f/2.8 on a 1.4x versus a 2x, or adapting a full-frame lens to a crop-sensor body for a wide-angle advantage.
The book also covers the operational side: correct installation torque, rear-element clearance checks, firmware compatibility, and care routines for humid and dusty environments. It includes a troubleshooting guide for the most common failures, such as stuck zoom rings, intermittent aperture communication, and soft focus at the long end. For those who work in the industry, there is a dedicated chapter on business models, including renting converters by the day, offering compatibility testing services, and private-labeling budget converters with quality control. The final chapters look at the future of the category, including computational corrections and the slow decline of the DSLR flange distance, plus a glossary of the terms you need to know.
Reader Reviews
Eric Hernandez
★★★★★Good reference overall. I'm a rental house manager and I appreciate that the chapter on installation actually gives torque specs and a proper check for rear-element clearance instead of the usual vague advice. The troubleshooting section solved a recurring aperture error we had with one of our 1.4x converters. I dropped a star because the future trends chapter felt a bit thin on the computational side - they mention corrections but don't give enough technical depth on what's actually implemented in current firmware.
Eric Wilson
★★★★★Finally, a book that treats lens converters like technical instruments instead of magic accessories. The chapter on understanding focal length multiplication versus effective aperture is worth the price alone - I had been shooting at f/8 on a 2x converter for years thinking I was getting f/8, when the physics means f/11. The worked example comparing a 70-200mm on a 1.4x versus a 2x was exactly the kind of side-by-side analysis I wanted. The glossary is solid, and I've already flagged a few terms to teach my assistant.
Jennifer Young
★★★★★It's a thorough book, but I found it a bit dry in places. The first chapter is dense with optical theory, and while I understand that's the point, I was hoping for a little more practical application upfront. That said, the chapter on maintenance is genuinely useful - the cleaning routine for the rear glass is something I'll actually do. The reviews section is also helpful. If you're a serious enthusiast, it's a good buy, but beginners may find it overwhelming.
Betty Rodriguez
★★★★★I'll be honest - I bought this expecting more on the creative side, like how to use converters for landscape or portrait work. The book definitely focuses on the technical and business angles, which is fine if that's what you want. The chapter on choosing the right converter is solid and I used it to decide between a 1.4x and a 2x for my macro work. But I wish it had more images and diagrams of the optical effects - the text descriptions are clear, but a few MTF charts would have helped me. Still a useful reference for my shelf.
David Walker
★★★★★This is the book I wish I had when I first started using teleconverters for wildlife photography. The explanation of how the focal length multiplier interacts with the Newtonian physics of the aperture is the clearest I've read anywhere. The chapter on using converters in the field - particularly about backing up the converter body and checking the rear element - saved me from a repair bill. I also appreciated the neutral tone on brands; the section on business opportunities gave me real ideas for monetizing my gear. Highly recommended.