Sharp Lens
The Contax G90 2.8 is the longest focal length in the Contax G series and the sharpest lens in the series. Word on the street is that this G90 is just as sharp as the Leica 90mm f2 AA at f2.8. The price is very competitive, in fact it’s cheaper than several other Contax G lenses.
Auto Focus
The most popular of the rangefinder camera systems is the wide-angle lens because the viewfinder window has a fixed range of view, and telephoto lenses have a very small area in the center of the viewing surface. Not many people use 90mm lenses in the Leica M system for the same reason. Interestingly, the Contax G90 is easier to use than the Leica 90mm because it has autofocus. That said, the G90 isn’t the easiest to focus up close.
Sonnar
This 90mm lens from Contax uses the Zeiss Sonnar structure, which is a classic Zeiss design and is mainly used for medium and long focal lengths. There are also lenses using the Sonnar structure in the Rollei 120 film system. It’s easy for Zeiss to create a Sonnar with a large aperture of 90mm.
Bokeh
The 90mm lens has a large aperture, which makes the subject stand out and defocus the background. However, the bokeh of the Sonnar structure isn’t particularly impressive. The background is a bit cluttered.
Focusing at close range
If you’re using a g1 or g2 with 90mm lenses, you might find that they have trouble focusing at close range. If you’re looking through the viewfinder and it’s aiming at 5 meters, but it shows 1 meter, then you’ll need to refocus.
If you’re taking portraits of friends, it’s a good idea to check the distance display in the viewfinder. In real-world use, I rarely lose focus when taking pictures of stationary objects, but it did happen a few times when taking pictures of moving objects.
Conclusion
If you want to install a telephoto lens on your G1 or G2, then the Sontar G90 f2.8 is your only option. This is where Zeiss is making a smart move, and you are too.
