Oops

Great to see another Nikon in the RFF family. Kiu hooked me up with a beautiful 50 for my S3. I also have a 35 and 105 but lately I have been thinking wide and since those are rare and $$$, the CV S-mounts that Stephen is closing out at Camera Quest have been getting very tempting. Don't forget about that option.
 
The CV s-mount lenses on Cameraquest are a great deal. I bought a 25/4 last year and it's a great lens.

Cosina Voigtlaender didn't get much success with its line of Nikon-mount RF lenses. First of all, there really aren't very many Nikon RF shooters. A collector isn't necessarily looking for modern glass. Also, those few of us who do shoot Nikons regularly have had years to put together our lens kits. The CV 21/4 and 25/4 are reasonably priced compared to their Nikkor alternatives. But the rest of the CV lenses duplicate existing Nikkors.
 
Way to go, Ralph!! Just do it: buy the beast, learn its secrets, squeeze its capacities and powers and then hang out to dry.

I've been looking at Nikons for the last two months, but never had the guts to go for one. Keep us appraised about the learning process! 🙂 That is, how do you adapt to the switch from using Leicas to shooting Nikons.
 
VinceC said:
>>Pretty Rover. Now you need a Leica M to Nikkor converter ...<<

No such thing. M lenses sit slightly closer to the shutter (due, I suspect, to the larger focus mount on the Nikon), so you couldn't focus to infinity or couple to the rangefinder.

Anyway, Nikons should be shot with Nikkors.
Click to expand...

My early morning attempt at humour, Vince ... Leicas should be shot with
Nikkors too 🙂

Roland.
 
Hi there Brian.

The S2 is growing on me. It is a "stout" but compact body. It seems to be a little bigger than my M3, or Canon P, but honestly it is if anything just a mm or so bigger in thickness. The focusing dial is loosening up with play. Hmmmm, I think the RF patch (rose colored) is a bit more visible than the cooler patch of my P, 1:1 viewfinder is very nice, the 50mm framelines are way out on the edges though for me even when I am not wearing my glasses. This won't be a big deal for me. The shutter isn't very quiet, but again, not a big deal for me. Overall, I got a nice user, I have to get it out for some play.
 
Brian Sweeney said:
I bought a few Helios-103's and will be re-shimming them for the Nikon S-Mount and filing the lock pin, as required. PM if interested.

I also will be attempting to adapt a Summicron Type I Rigid to S-Mount. The lens module unscrews, and the back-focus looks like it should work. Just have to meld a mount to the DMUOO.
Click to expand...


Brian's back!!! Welcome! Welcome! Welcome! I look forward to more lens experiments.
 
VinceC said:
Nippon Kogaku had no way of knowing, in 1947-'48, that its cameras would one day be so popular. Their 50mm lens designs were all for the Canon Hansa, which was based on the Leica standard lens, which is actually a 51.8mm lens. Fairly late in developing their first camera, Nikon decided to use a mount based on the Contax, whose 50mm lenses are actually 50.0 millimeters. But Nikon didn't want to go through the hassle of reformulating the lens for a camera that might well have bombed. So the Nikkor lenses are 51.8mm. It gets complicated because in the Contax/Kiev/Nikon mount, the focus helical for 50mm lenses is built into the camera body and couples to a rangefinder mechanism that is calibrated to the 50mm lens.

Long story short -- lenses are interchangeably accurate when focused to infinity, but the closer you focus, the more innaccurate they become. With 35mm and wider lenses, depth of field masks the difference. With 50mm lenses, shooting at f/4- to 5.6 can usually mask the difference. With 85mm and longer, Contax and Nikkor lenses can accurately interchange only if they're focused on infinity.
Click to expand...

Vince,

According to Nikon's website:
"However, since the standard 5 cm Nikkor lens — which was being produced before W.W. II — had the same focal length (51.6 mm) as Leica, they wanted to keep the optical design. So they decided to adapt Contax's mounting shape, while using a Leica-type lens focusing mechanism — the birth of a "combined" mount. Contax's standard lens had a focal length of about 52.3mm, which meant that this Nikon mount could obtain correct focus with both a Contax lens and a Nikon lens at infinity."

So I think that Stephen might be wrong on this one, because the actual focal length for the Contax mount is 52.3mm and not 50mm.

Another point: it seems to me that the depth of focus increases with the focal length. So the focusing error should be worse for shorter lenses, while tele lenses should be more forgiving.

Cheers,

Abbazz
 
Abbazz,
Thanks for the info from the Nikon website.

>>Another point: it seems to me that the depth of focus increases with the focal length. So the focusing error should be worse for shorter lenses, while tele lenses should be more forgiving.<<

I think you also have to take into account the magnification of the lens.
The longer the lens, the more precisely it must be focused. That's why the LTM version of the CV 25/4 is a zone-focus-only model, as are the 15mm and 12mm CV lenses. Also, it's well known that longer lenses are harder to focus with a rangefinder, which is why there no coupled lenses longer than 135mm (except for a couple of exceptions that proved the point).

From depth-of-field tables in the 1957 Nikon Manual --
all lenses wide open and closest focus:
135mm f/3.5 -- 5-feet -- 1" depth of field
105mm f/2.5 -- 4 feet -- 0.625" depth of field
85mm f/2 -- 3.5 feet -- 0.75" depth of field (0.5" at f/1.5)
50mm f/1.4 -- 3 feet -- 1" depth of field (0.75" at f/1.1)
35mm f/1.8 -- 3 feet -- 2.75" depth of field (3.75" at f/2.5 -- 4.25" at f/2.8)
28mm f/3.5 -- 3 feet -- 8.75" depth of field

(EDIT -- people on this forum generally seem to agree that modern film emulsions make depth-of-field tables of the 1950s too lax and should be tightened up by perhaps 25 to 50 percent.)

I'd say there's some empirical evidence here that rangefinders lost their accuracy when absolute depth of field falls below 1" -- my 105 and 85mm lenses are the toughest for me to accurately focus.
Vince
 
Last edited:
VinceC said:
I think you also have to take into account the magnification of the lens.
The longer the lens, the more precisely it must be focused. That's why the LTM version of the CV 25/4 is a zone-focus-only model, as are the 15mm and 12mm CV lenses. Also, it's well known that longer lenses are harder to focus with a rangefinder, which is why there no coupled lenses longer than 135mm (except for a couple of exceptions that proved the point).

From depth-of-field tables in the 1957 Nikon Manual --
all lenses wide open and closest focus:
135mm f/3.5 -- 5-feet -- 1" depth of field
105mm f/2.5 -- 4 feet -- 0.625" depth of field
85mm f/2 -- 3.5 feet -- 0.75" depth of field (0.5" at f/1.5)
50mm f/1.4 -- 3 feet -- 1" depth of field (0.75" at f/1.1)
35mm f/1.8 -- 3 feet -- 2.75" depth of field (3.75" at f/2.5 -- 4.25" at f/2.8)
28mm f/3.5 -- 3 feet -- 8.75" depth of field

(EDIT -- people on this forum generally seem to agree that modern film emulsions make depth-of-field tables of the 1950s too lax and should be tightened up by perhaps 25 to 50 percent.)

I'd say there's some empirical evidence here that rangefinders lost their accuracy when absolute depth of field falls below 1" -- my 105 and 85mm lenses are the toughest for me to accurately focus.
Vince
Click to expand...

Vince,

I had it wrong about the focusing error being worse for shorter focal length lenses.

I was thinking about depth of focus, which indeed goes shallower for lenses with shorter focal length. Any difference in registration distance on a wide angle lens will therefore be much more visible than on a tele lens. But in this case, the focal length difference between Nikon and Contax only impacts on the precision of the rangefinder focusing and has nothing to do with the registration distance and depth of focus.

You were perfectly right, the focusing error is none at infinity and increases when you focus closer, and it also increases with the focal length of the lens.


Cheers,

Abbazz
 
You must log in or register to reply here.
Back
Top Bottom