A reader sent me a diagram showing the arrangement of the focus points in the Pentax K-1 Mark III‘s viewfinder:
Legend:
A few words of explanation because, in spite of this diagram not being a Ricoh Imaging document, it’s as close to reality as it gets.
The diagram is based on the following information published by Ricoh Imaging:
– SAFOX 13 to include 101 focus points, of which 25 cross-type
– the diagram on this page https://pentaxofficial.com/en/7210/
The latter shows 13 breaks in the horizontal lines, of which two on the left part, nine in the center and two on the right part. There are therefore 13 rows of focus points: two on the left, nine in the center and two on the right.
Having nine rows in the central part, of which five include cross-type focus points and four are purely made of linear focus points, leads to 9×9 = 81 focus points in the centre with an alternation of cross-type and linear focus points.
Having 81 focus points, of which 25 cross-type, in the central part, leads to 10 focus points, all linear, in two rows on each side to obtain a total of 101 focus points.
The linear focus points in the central part have to be non-selectable assistance sensors because, since they are not cross-type, it would be suboptimal to select one of them instead of one of its cross-type neighbors.
As for the two brackets on each side, one can see slight traces of them on the diagram published by Ricoh Imaging when appropriately enlarging it and enhancing the picture’s contrast.
Credits: thanks to Fab35, Hombre, and Mistral75 from the Chassimages Forum.