[rollei_list] Re: Back-Focus and Retro-Focus ...
- From: "Eric Goldstein" <egoldste@xxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Fri, 11 Jul 2008 08:49:50 -0400
Hi Carlos -
OK, sounds like we agree that a 90 mm lens does not have the back
focus/clearance issues an 80 mm lens does when hanging on a 66 SLR
(the crux of this discussion) and yes, interesting how Praktica and
other lower end makers solved this engineering problem inexpensively
while maintaining some quality...
Eric Goldstein
--
On 7/11/08, Carlos Manuel Freaza <cmfreaza@xxxxxxxxxxxx> wrote:
> --- El jue 10-jul-08, Eric Goldstein <egoldste@xxxxxxxxx> escribió:
>
>
> > Very interesting information, Carlos. It is important to
> > note that this lens:
> >
> > http://araxfoto.com/lenses/vega-12/
> >
> > is badged a 90mm/2.8, which is important to the issue at
> > hand.
>
>
> The Vega-12b 2.8/90 was the standard lens for the Salyut MF camera, the
> Salyut was the original Hasselblad 1600F/1000F copy, the Kiev 88 is an
> improved Salyut and the Kiev 88 uses an Arsenal/Arsat/Volna 2.8/80 five
> elements lens, but the Vega 90mm can be used like the standard lens too.
> The standard lens for the Hasselblad 1000F was the EKTAR (Eastman Kodak
> TessAR)2.8/80, a four elements lens, no problem with the mirror, this camera
> could only offer a 60mm lens like wide angle lens (no "retrofocus" design)
> due to the mirror movement issue.
> The new 1957 Hasselblad 500 C (Compur) with built-in leaf shutters for the
> lenses required to re-calculate the 2.8/80 five elements Planar (not used for
> the 1000F) and then the seven elements Planar 2.8/80 was built and the
> retrofocus design allowed new and shorter wide angle lenses.
> I think eastern Europe MF SLR camera manufacturers managed the standard
> lenses and cameras construction (as John Wild suggested) to use cheaper five
> elements standard lenses, even adding 10mm for the focal length like the Vega
> Lens and the Salyut camera sample but maintaining the lens quality regarding
> the western Europe and Japan MF lenses, the Carl Zeiss Jena lenses specially.
> If you don't have a lot of cameras and lenses measurements to compare and
> the knowledge to interpret them, it's almost impossible to obtain a
> definitive conclusion, but since the evident lenses construction differences
> are for standard lenses only, we are talking about a few mm that some slight
> design and construction differences could explain.-
>
>
> Carlos
>
>
>
>
>
> ____________________________________________________________________________________
> ¡Buscá desde tu celular!
>
> Yahoo! oneSEARCH ahora está en Claro
>
> http://ar.mobile.yahoo.com/onesearch
> ---
> Rollei List
>
> - Post to rollei_list@xxxxxxxxxxxxx
>
> - Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe'
> in the subject field OR by logging into www.freelists.org
>
> - Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with
> 'unsubscribe' in the subject field OR by logging into www.freelists.org
>
> - Online, searchable archives are available at
> //www.freelists.org/archives/rollei_list
>
>
---
Rollei List
- Post to rollei_list@xxxxxxxxxxxxx
- Subscribe at rollei_list-request@xxxxxxxxxxxxx with 'subscribe'
in the subject field OR by logging into www.freelists.org
- Unsubscribe at rollei_list-request@xxxxxxxxxxxxx with
'unsubscribe' in the subject field OR by logging into www.freelists.org
- Online, searchable archives are available at
//www.freelists.org/archives/rollei_list
Other related posts:
