Zeiss Ikon -- close focus capability

[Huck Finn]

I opened an interesting e-mail from Hasselblad today. Because I had expressed interest in the close focus capability of the ZI in a prior correspondence with them, they were kind enough to update me on recent developments.

It seems that the second generation ZI prototype does not have the expected 0.5 meter rangefinder-coupled close focus capability. Rather, close focus for the ZI is 0.7 m - same as Leica M, Konica Hexar RF, CV Bessa R2/3A, & Rollei 35 RF. Hasselblad says that they have received no explanation from Zeiss for the change nor any explanation for why wide angle lenses have a minimum focus distance of 0.5 m but the body only rangefinder couples to 0.7 m. The lenses with shorter minimum focus distances can still be scale focused down to the distance spec'd, but it's at these close distances that you'd like the assistance of the rangefinder even on wide angle lenses.

My guess is that they were just not able to achieve parallax compensation at such distances. In order to accomodate the long base line, the viewfinder is located way over at the edge of the camera, so it was probably challenging enough to achieve parallax compensation for 0.7 m.

 

[Mazurka]

Odd time to hear such news.

Odd time to hear such news.

Parallex was the first thing that came to my mind too...

But on second thought, isn't it rather late in development that they only find out about this recently? One would think that Zeiss wouldn't incoporate the 0.5m minimum focusing distance into those lenses unless they were able to provide sufficient parallex correction in the finder. 😕

However squinty the G1/G2 finder maybe to some people, at least it can handle such distances without too much trouble.

 

[pvdhaar]

Maybe it's not parallax per se. The underlying reason may be that to focus accurately with a rangefinder under 0.7m requires production tolerances that are hard to achieve, especially for lenses with a shallow DOF close up..

They may also want to avoid a marketing disaster with rumoured incompatibilities at all costs whether true or not (anybody remember what killed off the Hexar RF?)..

 

[Huck Finn]

Peter, I don't think that depth of field would be an issue on the lenses in question, i.e 28/2.8, 25/2.8, & 21/2.8. The shallowest depth of field on any of these would be the 28/2.8 at 0.5 m, which would be about 2 inches. The depth of field on the 35/2 at its minimum focus distance of 0.7 m would be more shallow - about 1.7 inches - at f/2 than would the 28/2.8 at f/2.8.

I think you have a point about the marketing issues, but I have the same confusion as Mazurka. How could they be finding this out so late in the game? Perhaps they were basing their planning on the minimum focus distance of the Contax G lenses, which is 0.5 m for most wide angle lenses. As he said, the Contax G has a unique telescoping viewfinder which seems to be able to handle these distances in a way that standard RF viewfinders apparently cannnot.

Cheers,
Huck