twomblywhite Offline Upload & Sell: Off
|
Fred Miranda wrote:
This is an ongoing review of the CV 40/1.2 Nokton lens. I received it yesterday and so far, I was able to test it at infinity distance. I also compared it to the Voigtlander 35mm f/1.7 Ultron with a PCX (Plano-convex) front-lens side-by-side.
This thread will be updated with many other tests like OOF rendering, CA, Coma and sunstar rendition.
First Impressions:
The Voigtlander 40mm f/1.2 Nokton is not a hefty lens. At 415g, it's rather light considering its f/1.2 aperture. In comparison, the Voigtlander 35mm f/1.7 Ultron with adapter and PCX is exactly 100g lighter at 315g.
Here are they side-by-side:
https://www.fredmiranda.com/forum/ufiles/10/1535310.jpg
(CV 35/1.7 Without PCX 5m)
https://www.fredmiranda.com/forum/ufiles/09/1535309.jpg
(CV 35/1.7 With PCX 5m)
The lens has impressive build similar to other Nokton lenses. It's designed for the E-mount and therefore there is EXIF transmission and auto focus magnification. The 10-blade straight aperture is very responsive and allows precise increments in 1/3 stops. It can also be de-clicked. The lens is rather large in diameter but short in length balancing quite well on my Sony A7RII.
Focus shift
After reading about inconsistent performance results with this lens here and here, I wanted to first test it for RSA (residual spherical aberration). I found that the CV 40/1.2 is not well corrected for RSA and therefore focus shift is an issue.
Below is an example showing focus shift. The image on the LEFT was focused at f/1.2 and captured at f/1.2. The image on the RIGHT was focused at f/4 and captured at f/1.2. Big drop in resolution as you can see.
https://www.fredmiranda.com/forum/ufiles/12/1535312.jpg
Chromatic Aberration (LaCA)
Lateral chromatic aberration is not well corrected which I consider normal for a small fast lens. Curiously, Lightroom does not apply a profile correction for this lens automatically as it does with other native lenses. When applying auto CA correction in post, this color aberration is not longer a big issue.
Here are is an example of CA at f/4 at the edge of the frame.
https://www.fredmiranda.com/forum/ufiles/13/1535313.jpg
1:1 crop showing Lateral CA (uncorrected)
https://www.fredmiranda.com/forum/ufiles/14/1535314.jpg
1:1 crop showing Lateral CA (corrected automatically in Lightroom)
Field Curvature
This is a difficult lens to test because it has very noticeable focus shift as well as field curvature. It will make a big difference in resolution where you focus and which aperture was used to achieve focus. For optimum results at infinity distance, I would advise focusing towards the mid-field area AND shoot at working aperture with this lens.
On my next post I will post 1:1 crops showing how this lens perform at infinity distance and how it compares to the CV 35/1.7 Ultron with PCX....Show more →
Thanks! Excited to see your further testing. Pretty happy to see that the auto CA correction seems to work so well.
Fred would you mind taking one more image of the lenses side-by-side with the 35/2.8 ZA thrown in there?
|