RAW file size with OM 50mm 1.8 on 410

[rapyke]

<p>I recently picked up an OM Zuiko 50mm 1.8 and have been using it on my E-410 for a couple of weeks. After getting used to manual focus again, I have been enjoying it immensely -- some fabulous, nearly 3d images... wonderful.<br>

But, I have noticed that my RAW files are about 1 - 2 MBs smaller than when I shoot with a designed for digital, auto focus lens. 8.9 MB instead of 10.25 or so... I have trouble believing that the EXIF info for aperture and focal length could account for this big a difference.<br>

Any suggestions?</p>

[Matt Laur]

<p>Are you shooting that lens at f/1.8? If so, you're probably producing some highly out-of-focus backgrounds (which is always fun), and that reduces the level of detail in the resulting data. File compression can quickly reduce the size of the file when there is less edge detail to crunch. Just a thought.</p>

[rapyke]

<p>I have, of course, played with the wide open end of things, but even where I am shooting at f4 or 5.6 the files are considerably smaller... a couple of examples:<br>

http://bighugelabs.com/flickr/onblack.php?id=3409529706&size=large (Shot at f4 if my memory serves me correctly)<br>

and<br>

http://bighugelabs.com/flickr/onblack.php?id=3406346974&size=large (This was shot at f5.6 or 8)<br>

I am not really concerned - just curious as to why the RAW file is so much smaller.</p>

[patrick j dempsey]

<p>Maybe Olympus specifically designed the camera to record less information for non-ZD lenses... seems like a great way to make sure the "digital-specific" lens produces higher quality images... or perhaps they were expecting less sharpness from a non-ZD lens and figured it doesn't matter.</p>

[charedan]

<p>Have you tried photographing the exact same seen at same Aperture/Focal length with both OM Zuiko and Zuiko Digital?</p>

[rapyke]

<p>*stupid look on face* Um... it had not occured to me... I will and post results... Thanks Daniel!</p>

[richard_oleson]

<p>Only thing that comes to mind to me is that the file may include some lens data - lens in use, zoom setting, aperture, perhaps some data regarding the lens' distortion characteristics for use in postprocessing - which does not exist when using an MF lens without electronic connection to the camera.</p>

[melmann]

<p>I agree with Richard - compare metadata information for digital vs. non-digital lens and see if there's something missing. Sort of like scanning images from slides vs. importing digital files directly - the former doesn't tell you anything because the scanner was clueless!!</p>