Seiko 1.74 vs Nikon 1.74 vs Zeiss 1.74
Alex_a_p
lenses? I'm ordering a new pair of glasses and have an option to use
one of these brands.
Prescription:
-6.25 -1.25 25
-7.50 -.50 160
I had internet research but couldn't find any helpfull info such as
abbe values, materials and so on. Currenlty I wear Seico 1.74 lenses
made oversea and felt quite good with them until got problems with
coating. I also tried Hoya 1.71 but feel uncomfortable by some reason.
My optician called to lab and they told that Nikon uses the same
material as Seiko the only difference is the way how do they make it,
and moreover, all lenses with the same index are made from the same
material. Is that true?
Thanks,
Alex
Anon E. Muss
Very little "real world" difference between the lenses.
Mark A
news:1160268029.3...@m73g2000cwd.googlegroups.com...
It is not always true that all lenses with the same index are made from the
same material, but it could be true in the case of the 1.74 index material
that is being used by Seiko, Nikon, and Zeiss (that they are the same in
this case). Obviously, each manufacturer creates the base curves and
finished lenses differently.
Alex_a_p
Do I understand correctly, that if I ask them to reproduce the same BC
as on my current lenses (Seiko 1.74) I will see no difference in new
lences and my current ones?
What about abbe value? Can it be different? Do people usually sensitive
to it?
Robert Martellaro
>Thanks for answers.
>Do I understand correctly, that if I ask them to reproduce the same BC
>as on my current lenses (Seiko 1.74) I will see no difference in new
>lences and my current ones?
For many reasons, including variations in the true base curve and surface
design, opticians and their clients do not specify base curves.
>What about abbe value? Can it be different?
The Abbe value should be 33 for all 1.74.
>Do people usually sensitive
>to it?
Depends on the Rx, lens design (single vision or multifocal) and the person.
Hope this helps,
Robert Martellaro
~~~~~~~~~~~~~~~~~~
Optician/Owner
Roberts Optical
Wauwatosa Wi.
~~~~~~~~~~~~~~~~~~
"An expert is a person who has made all the mistakes that can be made in a very narrow field."
- Niels Bohr
Alex_a_p
Robert Martellaro wrote:
> On 8 Oct 2006 10:54:15 -0700, "Alex_a_p" <alex...@inbox.ru> wrote:
>
> >Thanks for answers.
> >Do I understand correctly, that if I ask them to reproduce the same BC
> >as on my current lenses (Seiko 1.74) I will see no difference in new
> >lences and my current ones?
>
> For many reasons, including variations in the true base curve and surface
> design, opticians and their clients do not specify base curves.
>
> >What about abbe value? Can it be different?
>
> The Abbe value should be 33 for all 1.74.
>
> >Do people usually sensitive
> >to it?
>
> Depends on the Rx, lens design (single vision or multifocal) and the person.
My Rx (single vision):
-6.25 -1.25 25
-7.50 -.50 160
Are all these lenses aspheric?
Robert Martellaro
>Thanks for reply, Robert. One more question below:
>My Rx (single vision):
>-6.25 -1.25 25
>-7.50 -.50 160
Some folks might be bothered by chromatic aberration at this higher lens power
when combined with lower Abbe value lens materials, although this can be
minimized by optimum lens positioning. Bring all of your old eyewear with you
when you see the optician.
>Are all these lenses aspheric?
Probably front aspheric, and in Canada and Europe some of these lenses might be
front and back aspheric, a k a bi-aspheric/atoric. If so, these lenses will be
about five to ten percent thinner than front aspheric designs.
You said that you had some discomfort with Hoya's 1.71/1.70 material. I doubt
that the problem was with the lens material, more likely it was due to other
factors, e.g. lens position, grinding errors, Rx, etc. This is an excellent lens
due to the slightly higher Abbe value of 36, only three or four percent thicker
than front aspheric 1.74 index lenses, less expensive than 1.74, and
incorporates an anti-reflection coating that will not give you any problems.