Beyond the numbers on the spec sheet.
A personal blog by an engineer with a background in optical design, exploring how lenses work.
Hello — I write under the pen name “Salamander” (さんしょううお). I have a background in optical design, and here I write about optics in plain language.
MTF, bokeh, aberrations, coatings — what is actually happening behind the numbers and terms on a spec sheet? I trace the light through the lens together with you, and nothing would make me happier than an occasional “ah, so that's what's going on.”
Who this blog is for
The level of difficulty varies, but I mostly write with these readers in mind:
- Camera lovers — who want to know the reasons behind the rendering, without the heavy math.
- Lens enthusiasts — who want to go deeper into what is behind the specs, down to the design trade-offs.
- Optics students and young engineers — who want to check things with proper terminology and ways of thinking.
How I write
No hype. I don't single out particular lenses for praise. Numbers are reported honestly and trade-offs are stated openly — what you gain and what you give up, always as a set. Where things are uncertain, I say so plainly.
Every analysis and chart on this blog is run in my personal environment (a personal PC with free software and programs I wrote myself), based only on public sources — papers, patents, textbooks, and published product reviews. I do not touch internal information of any company or product. This blog is a personal activity, unaffiliated with any organization.
Language
Articles are written in Japanese first and then translated into English. The article index lists everything available in English; anything not translated yet is linked through to its Japanese original.
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