I like cameras that produce real RAW files, just the data please – thats what I want from my camera. Admittedly its getting harder as more and more companies include adjustments into their RAW files.
My Leica M8 and the latest Leica M (Type 240) allow adjustments but when you import the images into a product like Adobe Lightroom all these types of adjustment like lens adjustment, noise adjustment etc are all optional and are off by default. This means you can customise as you want.
You may question why you may not want these adjustments, well any of these adjustments will reduce resolution and can cause smearing, especially at the edges.
With Leica M glass, you can get issues with the edges, these old designs work well with film but digital likes the light-rays appears perpendicular to the sensor. A little adjustment is sometimes necessary but its nice with the Leica M cameras to have the choice.
Interestingly testing has shown that the Leica SL does apply a little correction to M glass that cannot be turned off. This is a same as the design team for the Leica M have really shown how it should be done.
In case your interested the above image has all adjustments including noise switched off. It was taken with an old CCD Leica M8 at 640 ISO and a slow lens set to f/5.6 to give a bit of depth of field. This has resulted in a noisy image and one which resulted in a shutter speed of only 1/8 second.
Once of the joys of small mirrorless cameras is that with no large flapping mirrors you can shoot with quite slow shutter speeds, though 1/8 of a second and no image stabilisation is pushing it.