M8 and Lens Coding Importance

[frederick_muller]

<p>Hi, how important is it to use coded lenses with an M8? Is it more important for some lenses than for others? Thanks in advance.</p>

[marc_rochkind]

The purpose of the coding is to tell the body what lens is mounted. I can recall at least two things that the body does with this info:

 

1. Compensate for vignetting. (This part makes it more important for some lenses than for others.)

 

2. Record the lens description in EXIF data for each image.

 

3. <Others will chime in here with more.>

 

Note that the aperture is NOT transmitted to the body, so you won't see that in EXIF data. You will see the widest aperture of the lens, however.

[john_shriver]

<p>Importance is primarily for lenses 35mm and wider when used with UV/IR filters.</p>

[stuart_richardson]

<p>Yes, and the importance increases, the wider you go. At least if you are using UV/IR filters, which is very important for color photography. You can fix the problem manually in cornerfix, but it is not that fun...easier to let the camera take care of it. </p>

 

[miles_s.]

<p>Can some one elaborate on two comments above for me. Thanks.<br>

1) The use of lens coding "is primarily for lenses 35mm and wider when used with UV/IR filters." The use of the filter isn't encoded in the lens coding. So I guess the question is how is the lens data used in the colour correction?<br>

2) "Note that the aperture is NOT transmitted to the body, so you won't see that in EXIF data. You will see the widest aperture of the lens, however." Can't the M8 or M9 <em>estimate</em> the aperture by differencing an external light meter reading and the image intensity?</p>

[aplumpton]

<p>I think vignetting correction is the main advantage. As for colour effects, see Erwin's article:</p>

<p><a href="http://www.imx.nl/photo/leica/camera/M8/M8/page27.html">http://www.imx.nl/photo/leica/camera/M8/M8/page27.html</a></p>

[frederick_muller]

<p>Thanks guys, I appreciate the help. I'm considering an M8 after using the RD-1s for a long time. I think it has a lot of strengths and pretty good value now. I'm just trying to learn my way around some of its idiosynchracies.</p>

[charles_mason]

<p>only matters on jpegs- NOT the DNG files!!! also matters in reselling lenses...</p>