Among Friends Part 2

This is the second part of the post about the evening I spent with my friends and fellow bloggers in London. I thought I'd wait until I got back home to post more photos since publishing posts from my iPad is somewhat cumbersome. But back to my friends: Cristian and Kesh are not only fun to spend an evening with, they're also both talented photographers You can click on their names to check out their blogs. I haven't forgotten you either, Sam; it was a great that you could make it as well and not only your for your patience while posing for test photos.

As I already mentioned, I had a chance to try out Cristian's Ricoh GXR Mount A12 with the Voigtländer Nokton 35mm F1.2 on it. I only managed to get about half of my shots acceptably sharp. Needless to say, I was pushing the limits of the GXR, trying to manually focus the Voigtländer wide open at the the maximum sensitivity. My lack of familiarity with Ricoh's innovative peaking mode probably also led to some errors of judgment on my part.

The top row of photos was taken with my RX1, the bottom with Cristian's Ricoh GXR Mount A12 and Voigtländer 35mm F1.2 lens.

Voigtlander Ultra Wide Heliar 12mm F5.6 on NEX-7

I really wanted to like this lens; it's wonderfully compact, light, well made and has an ideal focal length to round out my kit at the wide end. With users reporting that the lens causes corner softness and color shifting on the NEX-7, I wanted to see for myself how serious the issues were before committing to purchasing one. Last Sunday I had the chance to test my friend Cristian's Voigtlander 12mm F5.6 on the NEX-7. To have a frame of reference, we also shot the same test scene with Cristian's Ricoh GXR A12 which was designed for use with M-mount lenses.

Looking at the results, it's clear that the Voigtlander 12mm is softer in all but the central region of the frame at F5.6 (which happens to be wide open), on both the Ricoh GXR and the NEX-7. So I'm posting this comparison at F8, which is probably the aperture you'd want to use the lens at. Not really an ideal lens for low light.

Crop locations shown on NEX-7 image (not corrected for color shift)

The comparison photos were taken with both cameras mounted to a tripod with the shutter activated by a remote (NEX-7) or the self timer (GXR). There are some minor differences in the lighting and framing, but the results are sufficient to draw conclusions from. I've compared crops from both cameras at 12 and 24 megapixels, “uprezzing” the Ricoh files using Genuine Fractals 6.0. The NEX-7 file was processed in CornerFix to remove the magenta color cast, but with a profile for the Voigtlander 15mm F4.5 lens. Here are the links to both RAW files; the crops below don't tell the whole story.

Sony NEX-7 + Voigtlander 12mm F5.6 at F8.0 ARW file (without CornerFix)
Ricoh GXR A12 + Voigtlander 12mm F5.6 at F8.0 DNG file

24 megapixel crops

Comparing the 24 megapixel crops, it's obvious that the NEX-7's native 24 megapixel sensor is capturing more fine detail in the central area of the frame. As you move to the edge of the frame, the output from the GXR starts to match (or even exceed?) the resolving power of the much higher resolution NEX-7. So while the Voigtlander 12mm prime performs well on the 12MP GXR A12 sensor, the same lens is not able to exploit the potential of the 24MP NEX-7 sensor.

12 megapixel crops

Will I add the 12mm Voigtlander to my kit? No. A lot of the time I use an ultra wide angle lens for architectural photography which requires a relatively uniform sharpness across the entire frame. While not as bad as I expected at F8, the edges and corners are still too compromised for me to consider the Heliar. If I was shooting with a Ricoh GXR Mount A12 I'd be happy with the performance, but for use on my NEX-7, I'll continue to wait for a native E-system ultra wide angle lens.