Archived posting to the Leica Users Group, 2010/10/27

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

Subject: [Leica] The T Stops here
From: mark at rabinergroup.com (Mark Rabiner)
Date: Thu, 28 Oct 2010 02:47:45 -0400

The notorious D40 and the D40x my primary side camera for the past 3.3 years
uses a CCD not a CMOS sensor as has been impugned. Nikon Was slow to CMOS.*
THE D60 is or was also CCD sensed.
In my past 4 days with my new nefarious D700 I'm given my first taste of
CMOS sensing. the format size I sense is the main influence in the results I
seem to be getting but I've severely cropped images smaller than the 1.5
crop format and seen huge advantages anyway. Also the thousand natural
setting on this camera which I try to figure out every day of which I've
been previously unfamiliar. Its like I'm still unboxing the camera with
every setting I figure out what it does.
4 years in digital R&D is a lifetime.

On a slightly related note if anyone is interested the configuration of the
older cheaper Nikon D40 (not X) 6 mp camera gives an unexpected benefit..
Here is the cheaper camera in the Nikon and whole camera case a few years
back of starter DSLR's (no live view) but the lower MP's of 6 instead of 10
gave it unexpected flavors.
It made for bigger pixel sites which made for higher usable ISO's with less
noise... Explaining why it went to 3200 the D40x which came later and more
wildly used only went to 1600.
More pixels make for more noise. In effect more pixels can more for less
functionality.
The D40 synced at an amazing 1/500th of a second. I think that's a side
note.
Its worth finding now as with every year the photodiode sites just get
smaller and smaller the the dumbly jacked up MP's. Perhaps Leitax a smaller
wide R lens to a D40 if there is one. You cant automatically focus most
Nikon glass with it anyway its the first with no internal focusing motor.
The Leitax ring would probably cost you the price of the used camera itself.

So a conservative choice in MP megapixel choice can be smart and can be more
a defining thing than what the myriad issues under the hood might indicate.
We pay more for the newer jacked up pixel count camera out in time for the
holiday and suffer. If our output is mainly uploading jpegs to online
galleries 10 mp's is overkill as is 6 mp's. What you will see on the screen
is noise. And a lower mp sensor design with bigger sites gives you less
noise. And I'm sure a richer fuller nicer happier result.
Less down rezzing makes Jack a happier boy.
___

*
People think when they see "EXPEED image processor" that it is paired along
with a CMOS sensor; it ain't true.

The image processor is the Hippo in the kitchen in discussions about CMOS
vs. CCD as its the second third of the equation of the total cameras
electronic design. The sensor choice is dependent on its harmony with the
image processing electronics able to back it up in effect like a backing
layer. Not literally.

Complicating sensor issues is the fact that there are other layers in play
affecting the total effect notably the unglorified Bayer Patter filter which
we dare not mention.
- the layer under that is the Micro lens layer which is a double layer on my
camera but I think that's common. How these twin micro lenses are converged
above each photodiode  to gather light and focus it in there is a major
contributing factor to the quality of the final image file, and its one of
many.
And positioned in FRONT of the sensor is the inglorious optical low pass
filter. I OLPF. Lowering the resolution so a balance must be struck - the
sampling frequency of the imager has to be matched correctly - moir? in most
cases is just not an option. The OLPF layer has a nefarious number of non
sequitur coated layers which do any number of unrelated things. So its a
many layered layer with a coat of many coatings.
An anti static layer made from Indium tin oxide; certainly impervious to all
the solvents you guys are squirting on it; that's one.
An anti reflective coating to deal with flare effects and ghosting that's
two. IR and UV balancing coats of many colors that's three. Three coating
layers. 

When shall we three meet again in thunder lighting or in rain!

Check out
http://www.dalsa.com/corp/markets/CCD_vs_CMOS.aspx
" Both CCD's and CMOS imagers can offer excellent imaging performance when
designed properly. CCD's have traditionally provided the performance
benchmarks in the photographic, scientific, and industrial applications that
demand the highest image quality (as measured in quantum efficiency and
noise) at the expense of system size. CMOS imagers offer more integration
(more functions on the chip), lower power dissipation (at the chip level),
and the possibility of smaller system size, but they have often required
tradeoffs between image quality and device cost. "






--------------------
Mark William Rabiner
Photography
http://gallery.leica-users.org/v/lugalrabs/
mark at rabinergroup.com
Cars:   http://tinyurl.com/2f7ptxb






Replies: Reply from jhnichols at lighttube.net (Jim Nichols) ([Leica] The T Stops here)
In reply to: Message from henningw at archiphoto.com (Henning Wulff) ([Leica] T Stops)