Archived posting to the Leica Users Group, 2005/09/08

[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]

Subject: [Leica] DMR test in British Journal of Photography
From: simonpj at mac.com (Simon PJ)
Date: Thu Sep 8 13:35:47 2005

The review echoes Erwin Puts' comments regarding the significance of
artefacts due to the lack of AA filter (interestingly the reviewer says that
Leica was unable to include an AA filter because of the lack of space
available in front of the shutter):

"However, the number of artefacts the back produces is poor with all the
lenses I tested. Due to the lack of a low-pass filter, chromatic artefacts
are very visible in any direction on fine and very fine structures, and
diagonal structures show some aliasing. This very high level of artefacts is
a disadvantage in fine structure or texture reproduction, and is relevant to
photographers wanting to output large prints.

To reduce artefacts from open aperture to aperture f/8, I recommend using
the built-in anti-aliasing function. A second way is to employ the usually
unwanted diffraction method - the loss of resolution, when stopping down a
lens too far, smooths the high frequency details of the optical signal.

This is related to the low-pass filter principle. Stopping down a lens to
f/11 or f/16 will decrease the artefacts without critical loss of
resolution."

"Conclusions:

This is a well-designed system best suited to shoot-to-print photography
which does not require much post-production. The dynamic range and noise
levels are very good at lower ISO settings, although the highest ISO
settings are not recommended unless the situation absolutely requires them.
Tone reproduction is more pleasant than precise, and the sharpening creates
brilliant edges without critical artefacts.

The digital back delivered higher resolution marks than any digital SLR I
have tested. On the other hand, the fine detail artefacts can be very high
to critical, and you will have to take care if you want to create large
format prints of fine details and textures. The corner shading and optical
distortion are reduced by the 35mm image circles, and the corner shading is
well compensated for."


On 8/9/05 6:57 pm, "Simon PJ" <simonpj@mac.com> wrote:

> The current issue apparently has a test of the DMR "plus four Leica 
> lenses".
> Has anybody read this yet? Or been able to access it via the BJP web site?
> (My trial subscription has just expired.)
> 
> Simon.
> 
> 
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information


Replies: Reply from rdcb37 at dodo.com.au (Rick Dykstra) ([Leica] DMR test in British Journal of Photography)
In reply to: Message from simonpj at mac.com (Simon PJ) ([Leica] DMR test in British Journal of Photography)