Two milestones have been reached on this journey.
Takumar Field Guide categories all have summaries and all lens pages now display batch data.
These are the most accurate quantitative information about Takumar M42 lenses available.
The numerical data will be reviewed annually to increase definition and accuracy.
A third level of description and graphics seen in the early pages of the Guide promises more qualitative interest.
Takumar demography is changing and can now be focussed a little more clearly.