Shooting a New Lens — Focus
Thanks to LensRentals.com, I have the Leica 21mm f/1.4 Summilux-M ASPH and the 28mm f/2 Summicron-M ASPH available for comparisons and testing when I head to Death Valley soon.
Focus check
With the Leica M9, the VERY FIRST thing one should with a new lens is to verify accurate focus with the lens on your particular M9. Rangefinder focus is a mechanical coupling and there is no guarantee that it is correct for any particular lens/body combination, even if the lens is brand-new out of the box.
As I show in Rangefinder Focus Error With Brand-new Lens in my didactic and essential Making Sharp Images, the serious photographer cannot assume that a brand-new lens focuses accurately.
So the first thing I did with the two rental lenses was to verify focus accuracy, shooting both lenses wide open on 6-10 images at varying distance, then checking focus accuracy in Photoshop after downloading the images.
Always make a focus-accuracy test wide open, otherwise depth of field masks the error. Besides, what’s the point of a 21/1.4 or 28/2 lens speed if one doesn’t shoot wide open at least some of the time? And focus must be perfect at f/1.4 or f/2 or the image will be degraded, perhaps to throw-away status. With the Leica M9, I also stack the 1.25X and 1.4X viewfinder magnifiers to rule out any user error (my eye).
Crops below are actual pixels from the center of the frame. Focus was spot-on for these frames and my other test images, so the lenses are good to go for comparisons and testing.
The sharpness of the 18-megapixel images makes me lust after a 36-megapixel Leica M10 someday. Why not? The lenses can handle it, and Nikon has already proven that the sensor technology has arrived.
See also :
- Lens Performance: What Matters
- Which Wide-Angle Lens is Best?
- Blur Can Be Beautiful
- Lenses as an Investment; Electronic Lenses vs Manual Control.
- My Reference Lenses For Testing Sharpness.
- Shooting a New Lens — Focus.
- What Does Depth of Field Mean on a 36 Megapixel Camera?
- Nikon D800 / D800E — Which Nikon Lenses?
- Reader Comments on Lens Reviews.