Arthur Nogood
Fixing Zeiss 25mm 2.8 ZF couldn't focus at infinity problem
Zeiss 25mm 2.8 ZF has a Nikon CRC (close range correction) similar design, or AKA floating lens, so it share the similar problem like Nikon 55mm 2.8 micro or Nikon 28mm 1.4d, they might not precisely focuses at infinity, due to bad manual assembling.
Every Zeiss lens has a hand written test certificate, mine is examined by K.Suzuki, it seemed that he dropped the ball.
My copy is first hand, no previous maintenance, and it couldn't focuses at infinity, only due to a short focal length and deep depth of field, even it couldn't focus, unlike the Nikon 55mm 2.8 micro, it does not yield nake eye differences even 100% pixel-peep.
Like Nikon 55mm 2.8 micro, Zeiss 25mm 2.8 ZF has multiple helicals that control different groups of lens to move oppositely during focusing, that mechansim is known as floating lens, to achieve great result at both farest and nearest ends of the focal range. But if assembled wrongly, it then turned out to be a disaster, and it is not infrequent.
Zeiss provide free calibration within warranty, but I desided to fix it myself.
Fixing Zeiss 25mm 2.8 ZF couldn't focus at infinity problem
Zeiss 25mm 2.8 ZF has a Nikon CRC (close range correction) similar design, or AKA floating lens, so it share the similar problem like Nikon 55mm 2.8 micro or Nikon 28mm 1.4d, they might not precisely focuses at infinity, due to bad manual assembling.
Every Zeiss lens has a hand written test certificate, mine is examined by K.Suzuki, it seemed that he dropped the ball.
My copy is first hand, no previous maintenance, and it couldn't focuses at infinity, only due to a short focal length and deep depth of field, even it couldn't focus, unlike the Nikon 55mm 2.8 micro, it does not yield nake eye differences even 100% pixel-peep.
Like Nikon 55mm 2.8 micro, Zeiss 25mm 2.8 ZF has multiple helicals that control different groups of lens to move oppositely during focusing, that mechansim is known as floating lens, to achieve great result at both farest and nearest ends of the focal range. But if assembled wrongly, it then turned out to be a disaster, and it is not infrequent.
Zeiss provide free calibration within warranty, but I desided to fix it myself.