Leica Inexpensive Adapter, Nikon RF to Leica Thread Mount. ~$70.

BrianS

Super Moderator
Apr 3, 2013
124
Just arrived in the mail, under $70 with shipping. This compares with adapters costing 3x as much.
The Amedeo adapters are works of art, his M-Mount adapter for internal mount Contax RF lenses has an indexed cam to correct the slight difference between the Zeiss 52.4mm focal length and the Leica. This Chinese adapter does not have an indexed cam, therefore is best used with Nikon S-Mount lenses.

But for $70- the focus was perfect with a Nikkor-SC 5cm F1.4 on my M Monochrom. I have not tested external mount lenses, will do a more complete test later.

 

BrianS

Super Moderator
Apr 3, 2013
124
I attempted to use the adapter with external mount lenses: found the external mount did not line up with the lens. The mechanism was about 60degrees out of phase. Then- saw the three set screws on the side of the mount. This allows the external flanges to be moved relative to the helical. I set the mount in a Zeiss 135/4 lens, aligned it all- fastened the screws back down. The person that designed the mount: A+. Assembling it: D-; Selling it for under $70: A. Conservation of inconience: 20minutes is worth the $200 saved over comparable adapters. Anyone using only internal mount lenses would not notice the difference.
 

BrianS

Super Moderator
Apr 3, 2013
124
Now- just to confuse everyone about everything: The adapter does not have an indexed cam, the RF cam moves 1:1 with the internal mount. Nikon S-Mount 5cm internal mount lenses will focus properly with the internal mount. The focus throw is 270degrees, which is the Zeiss standard. The RF cam moves from infinity to 0.9m meter with a 270degree throw. The Nikon external mount lenses cover the same range with a 260degree turn. That means that Zeiss Contax external mount lenses will focus properly with the adapter. Confused? Anyway, I was looking for an adapter to use with my Zeiss Opton 135/4 Sonnar and my Nikkor-SC 5cm F1.4 S-Mount lens. Works for me.
 

BrianS

Super Moderator
Apr 3, 2013
124
I'll post some pictures later in the week- but tested the adapter on a 1932 CZJ 13.5cm F4, Black and Nickel. Picked this lens up for "only" $99, but took some time to straighten out the bayonet mount. Somebody did some "bending" to make it work on a particular camera. It would not mount on my Contax II. Used a spanner used to straighten out dented filter rings and a "hammer" and chisel to get it back into shape. Mount on the Contax II, works on the adapter- shots with the M Monochrom show it to be in good focus throughout range. It has not been used in decades, but the glass cleaned up perfectly.
 

BrianS

Super Moderator
Apr 3, 2013
124
Some walk-around shots, now that it is starting to warm-up.

All with the 1932 Carl Zeiss Jena 13.5cm F4, wide-open.
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LarryHuffman

Rookie
Mar 20, 2019
3
Just arrived in the mail, under $70 with shipping. This compares with adapters costing 3x as much.
The Amedeo adapters are works of art, his M-Mount adapter for internal mount Contax RF lenses has an indexed cam to correct the slight difference between the Zeiss 52.4mm focal length and the Leica. This Chinese adapter does not have an indexed cam, therefore is best used with Nikon S-Mount lenses.

But for $70- the focus was perfect with a Nikkor-SC 5cm F1.4 on my M Monochrom. I have not tested external mount lenses, will do a more complete test later.

 

LarryHuffman

Rookie
Mar 20, 2019
3
I have just created a website devoted to the history of Canon rangefinders 1935-1968


this covers the cameras, the lenses and some accessories.

it also has coverage of the Minolta-35 camera and lenses, as well as some other M39 lens rangefinders that I have found interesting.

You may want to have a look....

all the best Larry Huffman

huffman@gmx.com
 

Woodallp

Rookie
Apr 2, 2019
4
Hi Brian, just picked one of these as back up to my Amedeo and I'm hoping to make it a permanent fixture to a Jupiter 9 and a permanently fixed and coded M adapter so your comments above are very useful, I had noticed the screws. I'm interested also about the Nikon comments; do you have a definitive reference about the Nikon/Contax differences and I have seen conflicting info and some of it is clearly BS (and by BS I don't mean you Brian).

Thanks Phil W
 

BrianS

Super Moderator
Apr 3, 2013
124
I knew about the differences between Nikon and Contax standards originally from a Modern Photography test done around 1972 or so. They tested a Contax II with 5cm F1.5 lens, and measured the actual focal length. It was ~52.3mm. The Leica Elmar, in the same test, was 51.6mm. I've still got that magazine, somewhere boxed up. The Russian lenses are based on the Contax standard, and most of the manufacturer's data sheets that I've seen indicate 52.4mm as the nominal focal length.

Note this plot is log-log, focus travel of the different focal length lenses.

TRAVEL
by fiftyonepointsix, on Flickr

That tiny gap in the 52.4mm vs 51.6mm is enough to throw things off. The difference in the Cam of the Jupiter-9 is set for the 52.4mm standard.
 
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Woodallp

Rookie
Apr 2, 2019
4
Thanks Brian, I have followed many of your discussions and fully agree; these differences are clearly stated again and again in Soviet "passport" documents and measurements even if they are occasionally masked by quality variations and wear. However, what I am trying to understand is the differences between Contax and Nikon. I know the mountings are mechanically compatible but what is the actual difference between the two?

As a takeaway from everything I read above would I be right in understanding that:

1) Nikon lenses are on the Leica standard and thus this cheap adapter works because the cam is not indexed and thus moves the same distance as required to focus a Leica lens.
2) Amedeo Contax adaptors are indexed to account for the 51.6 to 52.4 difference so focus Contax/Jupiter 50s correctly.

How is it then that the external mount on this cheap adapter works with the J9 if it would normally be "expecting" an indexed cam on the inner bayonet? What you say about turning angle may explain this I think.

You did at one point above write "Confused?" I think I am half confused. I also realise that there are Nikon lenses in Contax standard to muddy the waters.

I also hear that wide angle lenses are interchangeable but I am supposing that is because of higher DOF.

One day I'd like to get a Nikon 1.4 lens but I'm not planning to risk whilst I remain ignorant :)

Thanks for any more time you may be able to waste on me.

Phil
 

BrianS

Super Moderator
Apr 3, 2013
124
The best explanation I can come up with: The Contax External Mount lenses move ~270degrees from min focus to infinity, the Nikon S-Mount lenses move ~260 degrees from the same min focus to infinity. The adapter's helical that translates rotational motion of the lens to movement of the RF Cam is calibrated for the 270degree rotation of the Contax external mount lens. But- the internal mount lens does not have this translation of rotation to movement of the optics, it is just 1:1 with the RF cam of the adapter. That RF Cam's linear motion is designed with the 51.6mm standard of the Leica.

Wide-Angle lenses made for Nikon S-Mount and Contax mount also benefit from adjusting the Shim of the lens. I've adapted J-12 Contax mount lenses to the Nikon, and a 3.5cm F2.5 Nikkor for the Contax.
 

Woodallp

Rookie
Apr 2, 2019
4
Hi Brian, thanks a lot for this info, I think I will spend my weekend measuring and twisting on my ever-growing collection of adapters. At the end of the day the important thing is identifying which works with what I suppose, but at least it may give me an incentive to reassemble my J9 (Contax/Kiev) which has been in bits for months.
 

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