Hi

Films back from the TL120 test shots and they look very sharp although
I have noticed they're somewhat flatter in 3D to my normal Sputnik shots.

I'm wondering if I was just choosing crappy test materials to shoot
for tests, or if there's something about the focal length difference
between the two. Sputnik being 75mm vs 80.

Thoughts?

M

--- In MF3D-group@yahoogroups.com, "Mark" wrote:

>
> Hi
>
> Films back from the TL120 test shots and they look very sharp

although

> I have noticed they're somewhat flatter in 3D to my normal Sputnik

shots.

>
> I'm wondering if I was just choosing crappy test materials to shoot
> for tests, or if there's something about the focal length

difference

> between the two. Sputnik being 75mm vs 80.
>
> Thoughts?
>
> M
>

That would make no perceptible difference in terms of the 3D effect -
certainly not to the extent you suggest. You really need to
include close range subject matter and try to choose textured
subject matter to maximize the stereo effect.

Francois

Mark wrote:

> Films back from the TL120 test shots and they look very
> sharp although I have noticed they're somewhat flatter in
> 3D to my normal Sputnik shots.
>
> I'm wondering if I was just choosing crappy test
> materials to shoot for tests, or if there's something
> about the focal length difference between the two.
> Sputnik being 75mm vs 80.

I haven't noticed a difference between my 75mm and 80mm
images. I'm gonna guess its a matter of composition, but
that is _only_ a guess, Mark.
--
John Thurston
Juneau Alaska
http://stereo.thurstons.us

> "Mark" wroteFilms back from the TL120 test

shots and they look very sharp although

>I have noticed they're somewhat flatter in 3D to

my normal Sputnik shots.

>I'm wondering if I was just choosing crappy test

materials to shoot

>for tests, or if there's something about the

focal length difference

>between the two. Sputnik being 75mm vs 80.

>Thoughts?

Given that the cameras were both at the same
location and pointed in the same direction when
the views were taken:

1) The slide taken with the TL120 80mm lenses
will have more OFD than that taken with the
Sputnik 75mm lenses.
2) There will be more depth compression in the
TL120 shot verses the Sputnik shot.

However, when using the same viewer for each
slide, the differences will only be about 6% and
would take a keen eye to notice.

Chuck Holzner

Mark wrote:

> Hi

> Films back from the TL120 test shots and they look very
> sharp although I have noticed they're somewhat flatter in
> 3D to my normal Sputnik shots.

> I'm wondering if I was just choosing crappy test materials
> to shoot for tests, or if there's something about the focal
> length difference between the two. Sputnik being 75mm vs 80.

The Sputnik lenses do have problems with astigmatism,
in the peripheral areas, at all f/stops.

Did the Sputnik shots, look as sharp, as the TL-120
slides ?

The TL-120 slides should have exhibited, significantly,
better overall sharpness, especially in the peripheral areas.

If one is to attempt to compare the Sputnik with the TL-
120, it should be taken into account that they have little
in common with each other, except that they both use 120
roll film. The TL-120 costs about 10x as much, as the
Sputnik. I believe the TL-120 is priced below its true value.

The TL-120 does offer an accurate viewfinder, plus it does
offer a precise point of focus. The sputnik does not offer
an accurate view finder, nor does it offer an accurate point
of focus. The TL-120 does contain lenses that offer an overall
resolution capability that is far superior to the resolution
capability offered by the Sputnik, (triplet), lenses.

IMO. the differences in, "OFD", (Sputnik versus TL-120), when
the near point is at 10 feet, should not have been discernible,
in a standard MF viewer, as the difference would be only about
0.2mm.

The lack of a precise focus capability does make it difficult
to predict what the actual OFD of a Sputnik slide will be,
whereas the TL-120 DOES OFFER a precise focus, and therefore a
predictable OFD.

I consider the Sputnik, (if well tuned), to be a camera capable
of producing decent MF stereo slides, when used by a competent
stereo shooter. It is in a different class than is the TL-120.

DON