Compared to a crop using the DA TC1.4 with the DA55-300PLM doesn't give us more resolution and isn't very useful - this we can read in some posts. So I thought I could do some captures to see what I'm thinking about it.
I set K-1 to APS-C mode, the lens to 300mm + DA TC1.4x. That gives me 420mm focal length and the very narrow angle of view of a theoretical 630mm FF lens in FF mode - incredible ~3.15° x 2.08°!
If you turn on liveview 100% pixel level you'll realize what leverage the smallest camera motion gets when you just touch the lens' quick shift ring.
To get the smallest amount of shake I put the camera on tripod, for precise focusing set it to liveview, to minimize shutter shake influence set ES mode (electronic shutter) and use a cable release.
The wheather was bad, so I had to go to ISO 800 or 1600. The images were taken through a window pane. Unfortunately not perfect conditions.
I donīt know if a crop instead of using the TC would have given me better or same resolution. Anyway - I like the results and using the TC helps composing the image while photographing.
K-1 - APC mode - (DA55-300PLM+DA TC1.4x)@420 - ISO1600 - 1/200s - f/9.5 (open aperture) K-1 - APC mode - (DA55-300PLM+DA TC1.4x)@420 - ISO1600 - 1/200s - f/9.5 (open aperture) K-1 - APC mode - (DA55-300PLM+DA TC1.4x)@420 - ISO800 - 1/200s - f/9.5 (open aperture) K-1 - APC mode - (DA55-300PLM+DA TC1.4x)@420 - ISO800 - 1/50s - f/11 - pixel shift resolution