highdesertmesa Offline Upload & Sell: On
|
Nikon Zf as a platform for adapted/native manual focus lenses | |
Fred Miranda wrote:
highdesertmesa wrote:
Test results with the Leica 35 Summilux FLE II on the Zf via TTArtisan adapter. The TTA adapter has a nearly perfect hard stop infinity alignment at f/1.4. Infinity is just a literal horse hair's width from the hard stop. This should help improve results with this lens since it has a floating element design. Also keep in mind that although I've yet seen it tested, in some screenshots posted on Leica Forum a while back, Leica's marketing for the FLE II had a bullet point saying it was optimized for current digital cameras. I think this might be the same as was done for the new close focus 50 Summilux, which has been shown in testing to be improved in the corners over the previous version.
In any case, I went outside and took two quick handheld images at infinity not expecting much, one at f/8, one at f/5.6. I looked at the f/8 DNG in C1, and was like, ok, that looks dang good. Let's see f/5.6. Hmm. Just as good. I will need to go back out and test at wider apertures. I'm guessing that the corners start to show some weakness at f/4, but maybe I will be surprised yet again.
The image below was not processed in any way except to remove some vignetting so that the corners would be closer in brightness to the center. This lens also vignettes some when stopped down on the M11M.
I'm left with a lot of questions. Does the FLE II have improvements that impacted the results? Does the Zf focus IBIS's bias toward the focal point help when the focus point is set to the center as was done for this photo (that is, do other IBIS systems stabilize without regard for center/mid/corner or do they always bias to center)? Have there been any changes made to the Z6 II sensor used in the Zf such as cover glass thickness and/or microlens design – I would assume not, but not sure if there's even a way to find out. I think I'll get these answers after others start testing M lenses on the Zf.
Bottom line: Zf is giving me the same or better results with this M lens as what I am used to seeing on the SL2 and SL2-S, perhaps even a little better. Maybe that's not due to the Zf but but to the FLE II, I don't know.
Note: I did shoot a series at both f/8 and f/5.6 with the horizon at the top of the frame just to make sure there was no decentering/tilt involved in improving sharpness in the bottom half of the frame. The lens had already tested as perfectly centered on the M11M, so this was more to test for planarity of the adapter.
That's expected though. At smaller apertures, the thicker sensor stack issue is mitigated because the broader depth of field masks the issue. It's more noticeable when shooting at larger apertures. Having said that, it depends on where you focus. If you focus at the corners, the results will be okay even when shooting wide open since the main culprit is amplified field curvature due to using a lens designed for a thin sensor on a thicker stack.
Most M lenses on my SL2/SL2-S required f/8-f/11 for the same corner sharpness as f/5.6 gave me on the M11/M11M. Is f/5.6 with the 35 Lux on the Z really expected to to be sharp across the frame at f/5.6? If so, that's great news.
|