Curved Field vs Flat Field projector lenses

[Paddleman]

I was looking thru Adorama's page and came across two Kodak projector lenses.
One was a 102/2.8 "Curved Lens" the other a 100/2.8 "Flat Lens" and they both
had similiar numbers and the same selling price. Please help me understand the
differences in these lenses and their different uses.

Regards,
Gary

[Bhup]

If you are projecting onto a flat screen then a flat field lens..

"Paddleman" <paddleman@aol.comnospam> wrote in message
news:20030710071738.00183.00000224@mb-m03.aol.com...

> I was looking thru Adorama's page and came across two Kodak projector

lenses.

> One was a 102/2.8 "Curved Lens" the other a 100/2.8 "Flat Lens" and they

both

> had similiar numbers and the same selling price. Please help me

understand the

> differences in these lenses and their different uses.
>
> Regards,
> Gary

[J.D. Parker]

I second that.

With CF lenses and current generation slide mounts you will either
have the centre of the image or the periphery in focus - and it gets
boring (quite quickly) playing with the focus.

Jonathan

On Thu, 10 Jul 2003 11:49:26 GMT, "Peter Wear" <pwear@bigpond.net.au>
wrote:

>'Fraid not. The curved field lenses are meant to be tolerant of the curve in
>the film, and the flat field lenses less so. I wasted a lot of time trying
>to get good projection out of a curved field Leica lens - awful. Go flat
>field and take care with slide mounting - glass if needed - and enjoy sharp,
>edge to edge, images.
>P.
>
>"Bhup" <nospam@nospam.com> wrote in message
>news:s5cPa.185$nE2.31090@newsfep1-win.server.ntli.net...

>> If you are projecting onto a flat screen then a flat field lens..
>>
>> "Paddleman" <paddleman@aol.comnospam> wrote in message
>> news:20030710071738.00183.00000224@mb-m03.aol.com...

>> > I was looking thru Adorama's page and came across two Kodak projector

>> lenses.

>> > One was a 102/2.8 "Curved Lens" the other a 100/2.8 "Flat Lens" and they

>> both

>> > had similiar numbers and the same selling price. Please help me

>> understand the

>> > differences in these lenses and their different uses.
>> >
>> > Regards,
>> > Gary

>>
>>

>

[Bhup]

Curved field lens.. I guess a curved film .( but curved in the correct
direction the centre of curvuture must be towards the lens) is projected
onto a flat screen .
optically you have the same a flat film produced points of focus in an arc.
Curved film -> Flat sceen or Flat Film -> curved screen --- then who has
curved screens.


where as a flat field lens produces pints of focus from a flat film and then
on a flat screen
Flat Film -> Flat screen

Ok I'm being daft no offence to those who still believe the world is flat
unless viewed through a curved field lens :-)

B


..
"J.D. Parker" <NoSpam@Sympatico.ca> wrote in message
news:j1sqgvgcuobf60apth7i98vhn3vkql08sr@4ax.com...

> I second that.
>
> With CF lenses and current generation slide mounts you will either
> have the centre of the image or the periphery in focus - and it gets
> boring (quite quickly) playing with the focus.
>
> Jonathan
>
> On Thu, 10 Jul 2003 11:49:26 GMT, "Peter Wear" <pwear@bigpond.net.au>
> wrote:
>

> >'Fraid not. The curved field lenses are meant to be tolerant of the curve

in

> >the film, and the flat field lenses less so. I wasted a lot of time

trying

> >to get good projection out of a curved field Leica lens - awful. Go flat
> >field and take care with slide mounting - glass if needed - and enjoy

sharp,

> >edge to edge, images.
> >P.
> >
> >"Bhup" <nospam@nospam.com> wrote in message
> >news:s5cPa.185$nE2.31090@newsfep1-win.server.ntli.net...

> >> If you are projecting onto a flat screen then a flat field lens..
> >>
> >> "Paddleman" <paddleman@aol.comnospam> wrote in message
> >> news:20030710071738.00183.00000224@mb-m03.aol.com...
> >> > I was looking thru Adorama's page and came across two Kodak projector
> >> lenses.
> >> > One was a 102/2.8 "Curved Lens" the other a 100/2.8 "Flat Lens" and

they

> >> both
> >> > had similiar numbers and the same selling price. Please help me
> >> understand the
> >> > differences in these lenses and their different uses.
> >> >
> >> > Regards,
> >> > Gary
> >>
> >>

> >

>