See my Pentax K1 wish list at B&H Photo.
Aside: regardless of lens (omitting any serious duds), the Pentax K1 sets the gold standard for image quality. No other DSLR or mirrorless camera can approach the pixel-level detail, freedom from moiré and digital artifacts that the K1 offers in its SuperRes pixel shift mode (unsuitable for handheld operation and lots of movement and Motion Correction is a concern). I would rate the K1 as superior to the Leica S, and probably most all other medium format cameras. It is a major bummer that Zeiss is not likely to support the Pentax K mount, but Leitax.com will have a conversion option soon (Nikon to Pentax K). At the least, the K1 is a must-have camera for the still-life shooter.
A macro lens should perform at very high level in macro range; I explored that idea yesterday with the APS-C Pentax 35/2.8 shot on the full-frame Pentax K1. Reader Knut points out:
I'm not aware of another 35mm macro that covers full frame (Novoflex used to have one but it is long out of production and it had very poor contrast).
When shooting miniature landscapes (model trains etc.) using a wider angle is much more immersive. it allows showing the subject within it's environment.
The Pentax 35/2.8 may thus be interesting for K1 users for these reasons. But versatility is a big plus and so I was curious what it could do at distance. It is not uncommon for macro lenses to perform less well at distance, but a macro lens designed for APS-C shot at distance is even more of a challenge
Here the Pentax 35/2.8 Macro is tested on the full-frame sensor of the Pentax K1 at distance. Shot in SuperRes pixel shift mode for peak quality.
Images up to 28 megapixels with UltraHD crops, all from f/2.8 through f/13. This provides a detailed look at the “whole package” (lens and camera in SuperRes mode). Images include an overlay showing the bounds of the APS-C sensor area.
Like the map example, this example should be useful to both Pentax K1 users and Pentax APS-C users.