richard_chalfan

There seems broad agreement that there is a difference in color rendering between the M9 and the M (240). I suspect personal preference plays a large part in an individual's choice between the cameras.

That there is a difference raises the question "why"? This difference in color rendering is usually attributed in forum posts to the M9 having a CCD sensor and the M (240) having a CMOS sensor. But it is not at all clear to me that the sensor structure is the sole cause, or even a contributor, to the difference in color rendering.

There are a number of potential sources that could explain the difference in renderings that are independent of the sensor structure (CCD or CMOS). For brevity I will mention just two.

First, the chips are made by different manufacturers and each manufacturer's chip may have slightly different transmission characteristics for the blue, green and red filters they place over the pixels. Differences in the Bayer array filter characteristics could certainly cause subtle differences in color rendering.

Secondly, the color at each pixel site is generated by firmware algorithms that sample the response of the differently colored pixels at and surrounding the site being computed. The M9 and the M (240) may not use the same color generating algorithms in the processing firmware. If they don't, that could certainly cause subtle differences in color rendering.

So there are possible differences (and I haven't by any means listed all the possibilities) in how the M9 and the M (240) generate their color without the differences being inherent to the basic structure of the sensor (CCD or CMOS). I would be interested to know if anyone can definitively trace the difference in rendering to one camera using the CCD structure and the other using the CMOS structure. In fact, to my knowledge the details of the possible non-structural sources for the differences in color rendering are proprietary. So the information needed to determine what causes the difference in color rendering between the M9 and M (240) not be publically available!

<p>Several answers, like Sarah's, addressed the important points about distortion. But perhaps it would help to address the issue explicitly as there are two types of distortion you can see in a photographic image, and I think they are getting confused in some posts. There is rectilinear distortion and geometric distortion.<br>

Rectilinear distortion is one of the 5 "Seidel monochromatic aberrations" that can be present in your lens (there are also chromatic aberrations but they aren't relevent to this discussion). If the aberration "distortion" is present, straight lines in the object are not straight in the image. The commonly observed "barrel" and "pincushion" distortions are samples of the optical aberration, distortion. These aberrations are a result of the image scale, or magnification, not staying constant across the image plane. If the image scale increases away from the center of the frame you get positive, or barrel distortion. If the image scale decreases away from the center of the frame you get negative, or pincushion distortion.<br>

Geometric distortion is NOT an optical aberration, it is not caused by the lens but is caused by the geometry of the scene. Look at an example. <br>

Say you draw a precise circle a foot in diameter at your head height on a wall. Now if you back away (say 10 feet) from the wall but stay exactly opposite the circle it will still look circular (no surprise). Now, move 10 feet to the right and still stay 10 feet from the wall. Now look back to your left and look at the circle. It no longer looks like a circle, but it appears elliptical from your viewing angle and it is smaller because you are further away. That is geometric distortion. There is nothing "wrong", that is just how things really look off to the side, and that is how they will look in your image too.<br>

All lenses corrected for the aberration "distortion" will display geometric distortion. Just a fact of life.</p>

<p>Eastman actually received a patent for a plate coating machine in 1879. He commercially manufactured plates in 1880 and formed a partnership called the Eastman Dry Plate Company in 1881. That was followed by the Eastman Dry Plate and Film Company in 1884. <br>

While the so called "string set" Kodak camera of 1888 was a landmark product, it was predated by quality view cameras bearing the Eastman Dry Plate and Film Company label.<br>

SLR's? Kodak bought Folmer and Schwing in 1905 and owned the company until they divested it in 1927. During that time they offered many various large format single lens reflex camera models under the name "Graflex". While I realize that is NOT the kind of SLR you were asking about, it is historically accurate that Kodak made many early SLR's.</p>

<p>Eastman actually received a patent for a plate coating machine in 1879. He commercially manufactured plates in 1880 and formed a partnership called the Eastman Dry Plate Company in 1881. That was followed by the Eastman Dry Plate and Film Company in 1884. <br>

While the so called "string set" Kodak camera of 1888 was a landmark product, it was predated by quality view cameras bearing the Eastman Dry Plate and Film Company label.<br>

SLR's? Kodak bought Folmer and Schwing in 1905 and owned the company until they divested it in 1927. During that time they offered many various large format single lens reflex camera models under the name "Graflex". While I realize that is NOT the kind of SLR you were asking about, it is historically accurate that Kodak made many early SLR's.</p>

You say you find identical scratches in more than one lens. There are only two ways I can possibly imagine that you could see IDENTICAL defects within three DIFFERENT lens samples.

One is that you are not seeing scratches but internal reflections as has been suggested and which I realize you feel is not the case.

The other is that the lens uses a molded aspheric element where the master has those fine sleeks and they are reproduced on each copy. I can not imagine how ground lenses could have identical sleeks from one copy to another.

According to Leica data, your lens uses one aspheric element. It is a negative element just behind the iris (looking in from the front of the lens). If that is where the sleeks are, perhaps Leica use a molded aspheric element and have some QC issues.

It also seems very unlikely that some handling issues during assembly would have caused identical marks within all the lenses you looked at.

You must let us know if Leica addresses the issue for you.