f2.0 stop in Nikkor 50 f1.8 ai?

[rdtaylor_sea]

Deciding to go back film after many years. I just got a Nikkor 50 f1.8 AI (from the serial number it likely comes from 1979). It is in stellar condition but seems to have an extra f-stop at ~2.0. Having never used one of these lenses, I don't know if this is normal. Anyone run into this? Focus seems on from the limited shots that I've taken so far.

 

[2F/2F]

If it is anything like my Nikkor-Q 135mm f/3.5, then this is normal. It has an unmarked stop at f/4. My Canon FD 55mm f/1.2 S.S.C. has an unmarked stop at f/1.4 as well. I am glad that they do!

 

[dynachrome]

I think this is a sort of half stop between f/1.8 and f/2.8. It would be very difficult to make a 50mm lens with click stops at both f/1.8 and f/2.

 

[KenFretz]

Standard f stops

The f1.8 is 1/3 of a stop faster than the standard sequence of f 4.0, f2.8, f2.0, f1.4, so a stop at f2.0 is the normal position, there just isn't room to mark in on the lens. Nikon originally made 50mm lenses in f2.0 and f1.4 but as part of a marketing move in 1978 they started making the lower priced lens with a maximum aperture of f1.8 to make it seem that you were getting more.

 

[Denis R]

normal

my 50 1.8 D AF has 1.8 2 2.8 4 5.6 8 11 16 22 "click" stops

confimed on my N8008s

 

[rdtaylor_sea]

Thanks all - I appreciate the feedback. Sold all of my film Nikon gear 15+ years ago and have been using digital. Never had an f1.8 lens anyway so I was worried that I may have gotten a lemon. Thanks again.

 

[Christiaan Phleger]

This lens has that indent for F2, I've actually modified a few so that they have 1/3 steps at least to f4.

 

[PhotoJim]

Nikon originally made 50mm lenses in f2.0 and f1.4 but as part of a marketing move in 1978 they started making the lower priced lens with a maximum aperture of f1.8 to make it seem that you were getting more.

Not only did it seem like you were getting more... you were getting more! 1/3 stop more.

To be sure, the f/2 50mm Nikkor is a great lens, but if 1/3 stop has no value, why did Nikon ever bother making an f/1.2 lens when it already had an f/1.4?

 

[removed-user-1]

I've owned several 50mm f/1.8 Nikkors over the years and they all had an unmarked detent at f/2, and that is how it meters as well.

I don't think it would be that difficult to make a lens with 1/3 stop increments. My Pentax screwmount lenses have 1/2 stop indents at most settings, and I know at least one Nikkor lens that had 1/3 stop settings: the 105mm f/4 bellows lens.