p.1 #1 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
Hi,
I recently picked up the new Viltrox 85mm f/2 EVO (Z-mount) lens as a small, lightweight addition for my Nikon Zf and Z9. My main reasons for buying it were the size, the weight and the dedicated aperture ring to change settings directly on the lens.
However, the lens behaves very strangely on both the Zf and Z9 when the aperture ring is set to anything narrower than f/5.6.
Here is what I realized for now:
How the Viltrox 85mm f/2 EVO behaves:
A) Aperture set via the camera dial (Lensring on position A):
Good: The aperture closes down to f/5.6 but no further. The lens stays as wide open as possible for focusing to give the AF system enough light, and only closes down to the chosen smaller aperture (like f/8 or f/11) at the exact moment the picture is taken. This is completely normal.
B) Aperture set via the lenses aperture ring:
Limiting: The aperture keeps closing down all the way to f/16. As a result, the autofocus and viewfinder don't get enough light at smaller apertures. The viewfinder gets super noisy, and the autofocus starts hunting constantly and completely fails to lock onto the subject. It behaves alike an adapted fully manual lens.
For comparison: How a native Nikon lens with a control ring/aperture ring behaves (e.g., Z 50mm f/1.4):
A) Aperture set via the camera dial:
Good: Closes down to f/5.6 but no further. The lens stays as wide open as possible for focusing to give the AF system enough light, and only closes down to the chosen smaller aperture (like f/8 or f/11) at the exact moment the picture is taken. This is completely normal.
B) Aperture set via the lens control/aperture ring:
Good: Also closes down only to f/5.6 and no further. The lens stays as wide open as possible for focusing to give the AF system enough light, and only closes down to the chosen smaller aperture (like f/8 or f/11) at the exact moment the picture is taken.
I’ve already updated the lens to the latest firmware, but it didn't fix the issue. I also dug deep into the camera menus and tried changing the Live View View Mode settings, but unfortunately, nothing changed.
There seems to be no way to make the Viltrox behave like the Nikon lens and stay as open as possible while focusing and closes down to the chosen smaller aperture the moment the picture will be taken.
I was actually planning on getting the Viltrox 35mm f/2 EVO for street photography as well, but now I’m really worried it will have major focusing issues at f/8 or f/11 while using the dedicated lens aperture ring to dial in the aperture value. Same as the 85 EVO?
Switching the lenses aperture ring back to "A" and using the camera dial instead really defeats the purpose, where’s the fun in having an aperture ring then?
Interestingly, I haven't seen this mentioned anywhere by Viltrox or in the many online reviews. Everyone raves about the great performance and how much fun it is to shoot with the aperture ring. No one seems to notice the hit that the AF and viewfinder quality take in low light or street photography at smaller apertures when using the lenses aperture ring to dial in smaller aperture values (e.g. 8 to 16)
Did I get a defective lens, or is this a known firmware limitation/bug that Viltrox needs to fix? Or is there a camera setting I am not aware off?
p.1 #2 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
That's how all lenses work on Z. You only get DOF preview in liveview to 5.6.
If your aperture really is closing down to 16 and the camera is not set to 16, then that's a defect between the Viltrox and the camera.
Make sure the firmware is fully up to date.
There is also a new setting on the Z9 called a15 - Maximum aperture Lv - which forces a lens to remain fully open at all times during AF and then only closes down during exposure. This gives you better AF but then you lose real time DOF previewing. Whether or not this feature actually works with Viltrox lenses I don't know, haven't tested it myself.
p.1 #3 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
Sorry, I didn't express myself clearly.
When I set the aperture ring on the Viltrox to aperture 11, the aperture also closes fully to aperture 11 when I only half-press! the shutter button to focus. This should not be the case. As a result, the AF surely gets too little light
If the same aperture 11 is instead only set on the body and the aperture ring on the Viltrox is set to A, the aperture correctly closes only to 5.6 when the shutter button is half-pressed, in order to give the autofocus and viewfinder more light.
Only when the shutter button is fully pressed does the aperture close to 11. This then also happens at aperture ring settings 8 or 16, and intermediate values: It closes full to the 8 or 16 etc.
when the shutter button is fully! pressed.
The firmware on the Viltrox and the cameras is up to date.
My Nikon lenses do not know this problem and always close to a maximum of 5.6 when the shutter button is half-pressed and the aperture is 5.6 or smaller (8,11,16 …) to increase AF speed and reliability and to display the viewfinder image as clearly as possible. Only when the shutter button is fully pressed does the aperture close to the correct small value (8,11,16 ….)
Even the old SLR and DSLR cameras and lenses did it that way.
p.1 #4 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
I understand better now, and I don't know of a setting that would help here.
Testing this on my Z9, it seems that at any given aperture on the ring itself, the lens will close to that even during focusing for me. If I put the ring on A, then the lens does the whole 5.6 max thing.
That is VERY interesting and I'm glad you brought it up. I can also confirm that the a15 settings does NOT work while using the aperture ring to pick an aperture and DOES work when the lens is set to A.
This could be viewed two ways...one, while using the ring, you get full vintage type control with full DoF previewing that's not possible on a native lens, and if you want it the more modern way, you can set the lens to A.
Or you can see it as a bug. I'm not sure which it really is.
p.1 #5 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
Thank you so much for you help. It’s honestly a relief to know it’s not just me messing up my camera settings or overlooking something.
From what I understood from the Viltrox specs and all the reviewer videos, I really thought this lens would be a fully functional alternative to a native one. It definitely wasn't described as a lens missing an automatic aperture function in specific situations to support a proper AF and Viewfinder experience. I couldn’t find any hint about that anywhere, either.
I was really hoping for that seamless experience you get with any other current Canon, Sony, Nikon... or even older SLR and DSLR lenses. You know, where the AF speed and that nice, clean viewfinder image on a Z9 or ZF stays nearly consistent and we get great AF performance every time. I really expected it to function beautifully either way, regardless of the price. And even though Viltrox is "budget-friendly" compared to Nikon, it’s still a good chunk of money for a lot of people.
It makes me wonder: is this a general thing with third-party lenses on Nikon cameras, or is it just a specific quirk of the Viltrox EVO 85mm? Since the rest of my gear is native Nikon, I don’t really have a chance to compare other third-party lenses.
Right now, using the aperture ring of the EVO feels in this specific cases a bit like adapting an old vintage lens without automatic aperture to my Nikon, which isn't really how I understood the advertising and reviews.
It’s a bit of a bummer, and I do feel like it’s a shame that the AF and the viewfinder get so heavily restricted at apertures like f/8, f/11, or f/16, just by using the ring the way it was meant to be used.
Sad. Hopefully, Viltrox can smooth this out soon with a quick firmware update.
But if this is just how it is and can't be fixed, the dedicated aperture ring loses its charm for me, and honestly, the idea to pick up the EVO 35mm later on as well.
But hey, luckily we all have different preferences and ways of shooting.
p.1 #7 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
I think the way their party hard click aperture rings work is by reporting the current minum aperture at each setting. Sony’s lenses on a Megadap behave the same way too.
p.1 #8 · Viltrox 85mm F2 EVO Z-Mount: AF and Viewfinder limitation vs. Nikon lenses
Jman13 wrote:
I think the way their party hard click aperture rings work is by reporting the current minum aperture at each setting. Sony’s lenses on a Megadap behave the same way too.
That would make sense, except that a15 breaks completely when you'd think it would use that current set aperture as the "wide open" value. I dunno. I reported it and we'll see what the technical team says. My contact was very intrigued and asked some good questions, so I'm confident that they'll review the behavior.
I checked my TTA and Sirui AF lenses and they behave like this too.
While it's an interesting little gotcha with 3rd party glass, I have taken a great many shots with these lenses without knowing they do this and to no detriment of the image and now I know how to improve AF in low light/tight aperture situations, so thanks again to Gunter for pointing this out.
