Theory – JAPB

April 30, 2025

March-April 2025 Update

This update briefly lists all the new articles/pages added to JAPB during March and April of 2025

March 8, 2025

The Chinon 35–70/2.7–3.5 is not a Carl Zeiss Jena lens in disguise (or vice versa).

While I admit that even I was tickled by the obvious commonalities, on close inspection I have a hard time believing these lenses are related.

February 28, 2025

January–February 2025 Update

1-2/2025 has to offer: two new lens mounts, five company profiles, 25 new data sheets, one cold winter walk-around and a deep-dive into the development of a lens over 50+ years. Enjoy.

January 20, 2025

An unsung hero: the 1932 Carl Zeiss Jena Sonnar 135 mm

This article details the development of an arguably very influential lens design: that of the 1932 Carl Zeiss Jena Sonnar 135 mm f/4.

January 1, 2025

“No infinity focus”, and why it’s more complicated than that.

A JAPB reader recently asked me: “What is it you and other bloggers always write about some combinations of legacy lenses and digital cameras, that the combination does not allow infinity focus … Is this not a rather fringe issue?”
Here I dig into the question in some more detail.

December 31, 2024

October-December 2024 Update

This update briefly lists all the 20 new articles/pages added to JAPB during October, November and December of 2024.

September 30, 2024

July–September 2024 Update

This update briefly lists all the new articles/pages added to JAPB during July, August and September of 2024, including two West German lens mounts and 25 new lens data sheets.

June 30, 2024

April–June 2024 Update

This update briefly lists all the new articles/pages added to JAPB during April, May and June of 2024 including an article that summarises all 7 Mamiya 35 mm lens mounts.

April 29, 2024

Pentaconar lenses

Yes, everyone (whose ever been bitten by the legacy lens bug) has hear about Pentacon lenses. But WTF are Pentaconar lenses? Bear with me.

February 29, 2024

February-March 2024 Update

This update briefly lists all the 32 new lens data sheets and two company profiles added to JAPB during February and March 2024.

January 31, 2024

January 2024 Update

This update briefly lists all the new articles/pages (including 5 articles related to lens mounts and 13 lens data sheets) added to JAPB during January 2024.

December 31, 2023

November-December 2023 Update

Here you can find all new articles/pages added to JAPB during November and December 2023. My personal favourite of these ≈20 additions is the article discussing the ‘Soviet Nikon’.

October 31, 2023

September-October 2023 Update

11 new data sheets is not a lot, but it’s all we managed during two very busy months.

September 15, 2023

Fighting the BULGE: Adapting Canon FL and R lenses

Canon FL and Canon R lenses can be adapted just like Canon FD lenses, except if they have THE BULGE. Read more…

September 1, 2023

July-August 2023 Update

15 new lens data sheets (most of which focus on German and Soviet lenses) as well as two articles.

July 1, 2023

April–June 2023 Update

This Post holds a list of every new content that’s been added to JAPB in April-June 2023.

June 17, 2023

On terminology and names

YMMV, but I’ve always been fascinated by names and terms, and – in my previous research into the naming practices/logic of Meyer-Optik Görlitz – I gathered some other naming-related information, which has now taken the form of two more articles:

February 22, 2023

An ancient rivalry … and its contemporary effects

If you have not heard photographers complain about how some camera manufacturers’ (typically: the competition’s) control rings turn ‘the wrong way’, you’re either new to photo discussions, or have hung out only with photographers who never manually focus.

February 20, 2023

Too many adapters? The answer might be strategic…

If you’re not new to using legacy lenses on modern digital cameras (especially mirrorless cameras), you might notice that as the lenses keep piling up, so too do the adapters…

January 17, 2023

One ring to rule them all…

“One Ring to rule them all,
One Ring to find them,
One Ring to bring them all
and in the darkness bind them.” – J.R.R. Tolkien, The Fellowship of the ring

January 12, 2023

The genius of the Contax/Kiev mount

Introduction The lens mount that today is widely known as the Contax/Kiev1 mount was originally introduced together with Zeiss Ikon’s 1932 interchangeable lens rangefinder…

December 9, 2022

A rare glimpse of blue skies

But, and I kid you not, that photo – even though its exposure values are perfectly inline with a dim indoor shot – was taken on the 6th December at midday. That’s how little light Nordic photographers typically have to work with this time of year.

May 27, 2022

Lens mounts

JAPB has had two major updates this spring.
Firstly, JAPB has (finally) matured enough to deserve its own domain.
Secondly, JAPB’s most popular part (the JAPB guide to identifying your lens mount) has received a major upgrade…

June 29, 2021

Optical flaws and aberrations – new article series finished (was: in the works)

Update (December 2021): The article series mentioned below is now finished, in its entirety (until someone asks me to extend it). You can the…

JAPB is a website centred on photography and photo gear, with a special interest in using old lenses on modern cameras.

We (currently, I) are not trying to push you to buying new, expensive gear. Instead, our approach is the opposite (in all aspects). Instead we want to help you made informed decisions, and if we can be said to ‘push’ anything, that would be relatively cheap, old gear.

JAPB is non-profit, in fact this is a loss generator. Some day that might change, but we’ll make sure that does not happen at the expense of the audience.

You can read more here.