I have seen this with my own TLRs but also found that I needed new
spectacles. I opted for a diopter and now focus is dead on.
On 6/5/06, chatanooga@xxxxxxxxx <chatanooga@xxxxxxxxx> wrote:
>
> Listers
> I've pretty much convinced myself that my 2.8FX tends to focus about 3cm
> in front when nominally foucussed at 1m. I've verified this after noticing
> quite a few f2.8/ f4 type closeups didnt seem to be optimally sharp. I
> did a few angled-ruler type tests and shot several frames in quick succesion
> at the same focus to average out any film flatness issues. I see small
> shifts but the focus error is consistently in the front.
> Assuming the error is due to some fixed mechanical offset between the
> taking and viewing lense I'm wondering is this going to have a pro-rata
> effect at larger distances (for the same wide aperture)? My suspicion is it
> won't but would be interested to hear from someone less
> optically-challenged..! And suppose I put a Rolleinar on..........
> I would guess the 3cm I mentioned is equivalent to a very small
> film-plane offset - is such a small tweak possible (for the service centre,
> etc)?
> rgds
> Chat
>
--
Peter K
Ó¿Õ¬
