Leica X1 vs Micro 4/3 - high ISO vs. AF speed

<p><em>(I know there are photographers who are waiting for any mention of the X1 so they can dump on Leica for pricing it too high or for not making it M-mount or lens-interchangeable or for not making it the camera they personally want. They're welcome to join the discussion, but this thread isn't intended to be about those things.)</em></p>

<p>My question is about the tradeoff between good high-ISO performance and good (contrast-detection) autofocus speed.</p>

<p>My understanding (correct me if I'm wrong) is that with contrast-detection autofocus, the speed is determined at least in part by the refresh rate of the sensor (which also affects the choppiness of live view). The Panasonic GF1 sensor refreshes at 60fps, I believe, while the Leica X1 sensor apparently refreshes at 24fps, and everyone agrees that the Panasonic autofocuses much more speedily than the Leica does.</p>

<p>On the other hand, reviewers seem to agree that the X1 is unequaled in image quality for a compact camera especially at high ISOs, with many saying that it's as good as the Nikon D300s SLR. For example, if you download the photos in the left column <a href="http://www.dpreview.com/reviews/LeicaX1/page24.asp">on this page at dpreview</a> and examine them at 100%, the Leica starts pulling away from the Panasonic at ISO800.</p>

<p>Yes, yes, I know, the Leica's 1.5-stop high-ISO noise advantage is offset in the field by the Panasonic's 1.5-stop faster lens. Still, I've also been impressed with full-size examples of the X1 output at all ISOs that I've seen elsewhere, for example by <a href="http://www.flickr.com/photos/peterlueck/sets/72157623365667760/">German photographer Peter Lueck</a> (click on the thumbnail, then 'All Sizes,' then 'Original' if you want to pixel peep).</p>

<p>As may be evident, I'm not fully clear on the sensor differences between the Leica and the Panasonic, which is why I'm asking the question of those more technically in the know: is it at least theoretically possible to have a sensor with both a high-refresh rate/faster c-d autofocus) AND excellent high-ISO performance? Or are the refresh rate and high-ISO goodness going to always be to some degree mutually exclusive?</p>

From my extremely limited knowledge base, sensor size is a major factor in image quality and the Leica sensor is bigger. Is this reasoning valid?

<p>A high refresh rate could make the sensor warmer, since it's doing more work. The warmer the sensor, the noisier it gets.</p>

 

<p>I think the leica X1 has better IQ in the test because the 4/3 has a higher MP density and the 4/3 ISO rating is about 1/2 stop more than the X1. The refresh rate might affect noise but it is down on the list of variables imo. As for the d300s noise comparasion, sure the sensor size is about the same but don't forget, the X1 has a great f2.8 prime on it.<br>

Everything is a compromise. Which camera really depends on what you are after. IQ, lightweight , zoom vs. primes etc...want shorter shutter lag/faster AF? How about using M focus?</p>

<p> </p>

<p>This may help: <a href="http://www.boxedlight.com/x1/index.htm">http://www.boxedlight.com/x1/index.htm</a></p>

<p>Yes Les, thanks, I had read that review (and every other review of the X1 that I can find!).</p>

<p>The biggest objection of the reviewer you linked (besides price!) is that the X1 doesn't have interchangeable lenses (not a deal-breaker for me for the ways I'd use the X1, just as many micro-4/3 buyers keep the 20mm or 17mm lens attached all the time). He wasn't overly bothered by the slow AF. But almost all of the reviews I've seen agree on two things: the X1's image quality is unsurpassed in the compact-camera category and the X1 doesn't focus nearly as fast as the Panasonic does. Hence this thread asking to what degree that tradeoff will always be an issue.</p>

<p>I may post this in the Digital Camera forum, as this Leica forum generally deals more with film cameras and lenses than with digital cameras.</p>

<p>Ralph,<br>

I have no doubt that there will be a 'better' version in the future. This is just the first digital Barnack. I will wait. :-)</p>

<p>Les, speaking of the old Leicas, I didn't realize how close the X1 is in size and shape to the Barnacks until I saw <a href="http://www.rangefinderforum.com/forums/showthread.php?t=85016">this thread</a> ; see especially the second photo in the fifth post down, by "Paul T" (photo by adrianzg), the one with the six Barnacks.</p>

<p>I'm looking at the same sort of cameras as you and will probably go down the Panasonic route. If you are photographing things that move, no amount of high ISO performance will compensate for the fact that the image is out of focus. So for me and the sort of things that I photograph, AF speed is paramount. If you photography stationary things, then that will be less critical.<br>

<br />Cheers</p>

<p>Alan</p>

<p>Ralph,<br>

The concept is great but needs a little more refinement. I don't think it will be abandoned.</p>

<p>Mind if I link to my blog, where I examined exactly these issues, with a comparison of the X1 and the GF1.<br>

http://moneycircus.blogspot.com/2010/02/leica-x1.html<br>

Regards,<br>

Mark</p>

 

<p>The GF-1 is the better deal, that's for sure. However, as an X1 owner, I chose it because of the dedicated shutter speed / aperture dials and simplified menus. <br>

To the OP, you can't go wrong either way really. If interchangable lenses and fast AF are your priorities, the GF-1... if you want a digital with one foot in Leica's past, you get the X1. </p>

<p>If this camera was $400, that would be one thing, but at $2000 it's in the same price category as a good used M8 which will better it in almost every way.</p>