[rollei_list] Re: Contrast and Resolution
- From: Carlos Manuel Freaza <cmfreaza@xxxxxxxxxxxx>
- To: rollei_list@xxxxxxxxxxxxx
- Date: Thu, 8 Nov 2007 11:31:44 -0300 (ART)
The lens resolving power is the ability of the lens to
determine fine detail, for a traditional photographic
image, the image resolving power is a combo between
the lens and film resolving power.
The lens contrast has to do with tonal values, the
lens contrast is the ability of a lens to distinguish
differences for very similar or almost identical tonal
values in the image.
The point in the Zeiss paper published in the Zeiss
info No 51 is that the human eye distinguishes as the
best image the image with the best contrast and not
the image with the best resolving power, they show
very clear examples about it but the images are not
on-line. The article shows a photograph about a window
in the Aachen cathedral with the best resolving power
regarding to see the window details, if you pay
atention the image is plenty of details really,
however the image looks poor, unsharp due to the lens
low contrast; in the other hand the article shows
other photograph about identical subject where you can
see less resolved details than in the image with the
highest resolving power however this photograph looks
more sharp clearly because the lens contrast is
higher. There are other two photographs (identical
subject again)where the resolving power is the same
but the contrast different. The image with better
contrast looks a lot sharper than the image with low
contrast despite the resolving power was identical for
both images.
It is possible to have poor photos show in high
resolution, and good pictures with moderate
resolution. Two photos of identical resolution may be
entirely different in image quality due to the
contrast difference.
The lens resolving power is significant for the image
quality, but more important and more significant is
the lens contrast, this is the Zeiss point for this
article.-
All the best
Carlos
--- Neil Gould <neil@xxxxxxxxxxx> escribió:
> Hi all,
>
> The discussion regarding contrast vs. resolution is
> interesting and raises
> a point that I would like explained. How was
> resolution determined
> independent of contrast? Today, we see resolution
> specifications that
> include a contrast figure, and it is "common
> knowledge" (a.k.a. layman's
> understanding) that lower contrast will accompany
> lower resolution
> performance. Yet, the comments in this thread state
> the opposite! Can one
> of you provide a definition and/or a method of
> determining resolution that
> excludes contrast?
>
> Regards,
>
> Neil
>
> ---
> 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
>
>
Compartí video en la ventana de tus mensajes (y también tus fotos de
Flickr).
Usá el nuevo Yahoo! Messenger versión Beta. http://ar.beta.messenger.yahoo.com/
---
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:
