Topic: DIY adjustment guide for CZ 50 and 28 for infinity

Taken from this post: http://www.fredmiranda.com/forum/topic/402782

Posted by Shirozina: "Here is a rough guide to adjusting the 50mm 1.7 MM and 28mm 2.8MM if they fail to reach infinity with your adapter.
50mm - remove the rubber focus grip and slightly loosen the 3 x head screws - this releases the clamping action of a semi circular ring inside the lens which locks onto the focusing helical. Slide the now loose focusing ring slightly away from infinity and then slightly squeeze it to grip the helical and focus back on infinity. It should only need a slight movement of a couple of MM at most. CAUTION! if you undo the screws to much they will disengage with the inner ring and you will have to remove the front assembly thus: Using the proper friction tool or ( as I did ) a small roll of electricians tape unscrew the lens ring ( the one with the serial number on). You will need to apply a bit of force to get the required friction. The roll of tape is good as the sides are sticky and the center is open so as not to touch the lens. Under this are 3 screws which when removed give access to the clamping ring. CAUTION! this also holds the front element in place so keep the lens upright!
28mm - simply unscrew the front of the lens beyond the focusing ring - it comes off in one piece together with the lens ring. You can also use the 'electricians tape' method as with the 50mm. Down the side of the inner lens barrel are 3 screws which hold a clamping ring - loosen these and adjust in the same way.
I use an angle finder-C to set the lens up and then check 100% blowups on screen at max aperture. Previous to my adjustment both lenses were focusing a little short of infinity ( Not realy noticable through the VF even with the angle finder) but obvious at 100% on screen - whan properly adjusted landscape images 'snap' into focus that even stopping down coud not compensate for previously."

I hope this isn't a repost.

Re: DIY adjustment guide for CZ 50 and 28 for infinity

foto-z wrote:

Taken from this post: http://www.fredmiranda.com/forum/topic/402782

Posted by Shirozina: "Here is a rough guide to adjusting the 50mm 1.7 MM and 28mm 2.8MM if they fail to reach infinity with your adapter.
50mm - remove the rubber focus grip and slightly loosen the 3 x head screws - this releases the clamping action of a semi circular ring inside the lens which locks onto the focusing helical. Slide the now loose focusing ring slightly away from infinity and then slightly squeeze it to grip the helical and focus back on infinity. It should only need a slight movement of a couple of MM at most. CAUTION! if you undo the screws to much they will disengage with the inner ring and you will have to remove the front assembly thus: Using the proper friction tool or ( as I did ) a small roll of electricians tape unscrew the lens ring ( the one with the serial number on). You will need to apply a bit of force to get the required friction. The roll of tape is good as the sides are sticky and the center is open so as not to touch the lens. Under this are 3 screws which when removed give access to the clamping ring. CAUTION! this also holds the front element in place so keep the lens upright!
28mm - simply unscrew the front of the lens beyond the focusing ring - it comes off in one piece together with the lens ring. You can also use the 'electricians tape' method as with the 50mm. Down the side of the inner lens barrel are 3 screws which hold a clamping ring - loosen these and adjust in the same way.
I use an angle finder-C to set the lens up and then check 100% blowups on screen at max aperture. Previous to my adjustment both lenses were focusing a little short of infinity ( Not realy noticable through the VF even with the angle finder) but obvious at 100% on screen - whan properly adjusted landscape images 'snap' into focus that even stopping down coud not compensate for previously."

I hope this isn't a repost.

I wish I could see some pictures of this action because I just aquired a planar 50 MM and have exacly this problem:
it does not focusses to infinity.... :-(

Canon EOS 5D, D60, Fujica, Yashica, Praktica, Zenit, Spotmatic and some radioactive lenses...
Does your manual lens fit to your Canon EOS 5D? http://www.panoramaplanet.de/comp/index.html

Re: DIY adjustment guide for CZ 50 and 28 for infinity

Guys,
  Instead of opening new discussions, I want to reply to old one.

I bought Contax CZ 50/1.7. Its a beauty, thanks for providing the intro to this. But its not doing focus to infinity (the picture are not clear, as I was thinking. I compared with Canon 50/1.8. There is no comaprision ae infinity focus. Within 10m, CZ is a new world). Now I want to knwo few things, please help me.

1) What really is focus at infinity. From Physics point, how can this be happen except circle of confusion around depth (hyperbolic dist).
2)Can someone paste few or any picture showing clearly how CZ 50/1.7 focusses at infi. Clearly showing the resolution at around 20m.
3) I did as provided in the above text. First time, my lense was not focussing after 5-10m. Scared, I did the prcoedure again. I am back to normal, means still not focussing at infi, but doing before that.

Seems like my lense is fcoussing around 15-20m at infi scale.

Need help from people here. I really dont want to sell this lense. Within 10m, this is great..

Cheers...

Re: DIY adjustment guide for CZ 50 and 28 for infinity

Thanks for this. I did this procidure on my Contax Zeiss 28/2.8 and it worked wonderfully!!!

Thanks again Jaap Jan

CZ 18 28 50 85 135  MD 28 35 50 85 135 Rollei SL66 80 150 250  RTSIII Aria(2x) X700 X300

Re: DIY adjustment guide for CZ 50 and 28 for infinity

Many thanks for the easy to follow instructions!