R-D1s and Summicron-c 40mm

[ferdinandshen]

I wanted to use the tiny summicron-c 40/2 for such a long time -- even before I have the R-D1s. Getting the R-D1s in hand only elevated my desire for this lens, despite the fact I have a Summicron 35 4th. I got one for a good price last week. I have read some about the focusing cam coupling problem with R-D1s, but I decided to ignore them and try my luck.

When I mounted it for the very first time, it worked fine. Inf is ok, 1m is ok, all baby pictures turned out sharp. I was so happy. But after a week I noticed the focus action started to "slip" -- the image in patch does not move or only move a bit when I turn the focus ring. Then the Inf is way off, and everything is off. I mounted cron-c on M2, it is fine; I mounted cron 35 on R-D1sm it is fine too.

So what happened here? I noticed the position of cron-c's focusing cam is higher (about 0.5mm?) than my crons and Elmar. So it just previously engaged to the very top end of R-D1s' focus wheel, extremely close to the edge. It doesn't take long before it finally fell off the wheel after 1 week of heavy use.

Is there a way to bring up the focusing wheel by, like, 0.2mm? I really hate to see this good lens go just because of this.

 

[Paul T.]

FWIW, my Summicron C focused fine on the R-D1, they worked very well together with no focusing errors...

 

[LCT]

My copies of the 'cron 40/2 (here on a M4-2) focus fine but the lens has a sloping cam which can cause focussing errors if the tracker doesn't roll normally on it.
I would check if there are no dirts where i've put my arrows in the first place.

 

[Steve Litt]

Another happy cron 40 -RD-1 user here.I have had my RD-1 2+ years and my 1975 40 cron has been my standard lens since day one.

Regards
steve

 

[ferdinandshen]

Again, this copy of 1975 cron-c works well with my M2, no dirt, overall very clean (I cleaned it). As shown in LCT's picture, the sloping cam is very close to the top of the wheel. And in R-D1s it was just over the top. I am wondering if I can tune the wheel slightly higher.

 

[LCT]

... the image in patch does not move or only move a bit when I turn the focus ring...

Means that something prevents the tracker to roll tightly along the sloping cam of the lens at first glance. You might wish to press gently on the tracking wheel to check it it moves smoothly or not. If so, something must be wrong with the lens i guess but i don't know what sorry.

...It doesn't take long before it finally fell off the wheel after 1 week of heavy use. Is there a way to bring up the focusing wheel by, like, 0.2mm?...

Not sure if i understand what you mean sorry. The tracking wheel is pushed down by the focussing cam of the lens when you focus at infinite. The only way to bring it up then is to focus closer.

 

[LCT]

.... As shown in LCT's picture, the sloping cam is very close to the top of the wheel. And in R-D1s it was just over the top. I am wondering if I can tune the wheel slightly higher.

Still don't understand sorry. The sloping cam is not close to the wheel. The wheel rolls on it.

 

[ferdinandshen]

Yes, the wheel rolls on the cam, but the cam does not align with the wheel prefectly -- as we can see from your M4-2 picture. It is like the wheel "derail" from the "track" (cam). The focusing arm moves perfectly-- I have 4 other lenses to test it on.

I would need to adjust the vertical position of the wheel. If I can't, I would need to get rid of the cron-c.