"Best" 35mm focal length lens, for Nikon F mount

[MFstooges]

Nobody mentioned about Samyang 35mm F1.4? Sounds like it's a very good modern lens too and it has aperture ring.

 

[Angarian]

Nobody mentioned about Samyang 35mm F1.4? Sounds like it's a very good modern lens too and it has aperture ring.

Looking at the published test reports and most user reviews, it looks indeed quite good. And it is very attractively priced.

But it is not on the extremely high level like e.g. the Sigma Art 1.4/35. And with the Sigma both AF and MF is possible, whereas the Samyang is MF only.
And the OP is looking for a high-performing lens for his F6, so also having AF definitely makes sense.

Also built by Samyang (based on available public knowledge) as OEM manufacturer for new swiss lens brand Irix https://irixlens.com/
is the manual focus Irix 1.4/30:

30mm Photo lens (EN) - Irix lenses were designed with both the effort and experience, of not only engineers, but also photographers. Swiss precision and Korean innovation create Irix lenses.

30mm Photo lens (EN) - Irix lenses were designed with both the effort and experience, of not only engineers, but also photographers. Swiss precision and Korean innovation create Irix lenses. -

irixlens.com

It is also MF only, but with a very good built quality, and an excellent optical quality:

Irix 30 mm f/1.4 review - Introduction - LensTip.com

Best digital cameras and lens reviews. If you are looking for the information about digital cameras and lenses you are in a right place. We have many professional tests of digital photography equipment.

www.lenstip.com

 

[skahde]

Quality lenses for 35mm pretty much always have greater resolving power than a MF or LF lens. Perceptual sharpness is a function of (among other things) lens resolution divided by magnification ratio to make a given size print. Because the smaller negative needs more magnification, the lenses have to be higher resolution. I was first astonished by this when I started looking at the published resolving power of my Nikon lenses vs. MF lenses.

I only found this old rule of thumb to be generally true for budget medium-format lenses which mostly comprised triplets in folders, in Seagull TLRs or some lower examples on someones try on a tessar-design. I found top-notch medium-format lenses to be generally on-par with the best in 35 mm, e.g. a Hasselblad Planar 2.8/80 mm F outperformed a Leica M-Summicron 2/50 v4 in my tests. Many other were in the same ballpark where the visible differences couldn't be attributed to the format they were intended for rather than to the construction at hand. This may have shifted with newer lenses as there hasn't been as much development for MF lately.

 

[skahde]

Yep, noted and agreed.

But also take note that those limits of the film are one contributing factor, the other factor is still the lenses mtf. The apparent sharpness of the picture is the product of both. With a film of lower resolution a lens having higher contrast at lower frequency may produce more pleasing results even if it is not able to produce adequate contrast at high frequency.
For instance, I used a 2/35 mm AIS for decades, untill it litterally started falling apart in my hands and loved to use it on HP5+ or regular 100 ISO slidefilm. Nice, sharp images. But when I tried to use it with Tech-Pan to print larger and circumvent the necessity to use medium format I found I crossed its limits as the fine detail was just mushy although I used the whole set of tricks to prevent shake, use the optimum aperture aso. The Nikkor 2.8/55 mm was much more usable for this. Always pick the tool for the task.
With the latest construction you are on firm ground, though. Their MTF is so much higher at all frequencies, there simply is little to discuss. For film I still like to use some of the more temperamental classics and just added a 1.4/35 mm Nikkor AI to my inventory.