Well said. I have a feeling, though that the dpreview "tests" are biased. And not comparable - different test methods/-terms from brand to brand. An unbiased test site would have redone the test, when the camera couldn't focus the first time. Any camera can experience difficulties. As you said, Tom - it's never easy to focus in the dark.
Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: Tom C [mailto:[EMAIL PROTECTED] Sendt: 30. juni 2004 23:31 Til: [EMAIL PROTECTED] Emne: RE: Af speed of the *ist D In general, how easy is it for any camera to focus in low light? The fact that it makes a couple of attempts and then zeros in on the correct focus can be viewed as good, not bad. How easy is it to focus manually in low light? Pretty damn hard. What I find about most reviews, is that it's largely a matter of splitting hairs. Tom C. >From: "Jens Bladt" <[EMAIL PROTECTED]> >Reply-To: [EMAIL PROTECTED] >To: <[EMAIL PROTECTED]> >Subject: Af speed of the *ist D >Date: Wed, 30 Jun 2004 22:52:16 +0200 > >www.dpreview.com states as qouted below, that the AF is rather slow, you >must push down the biult-in flash maunally (AF assist) before takeing the >picture, if yoy don't want ti use flash light, and that the AF assist light >may require more than one attempt before focus lock is achieved. >Is this really the case? If so, not very flattering, is it? > > >www.dpreview.com testing *ist D; > > > >Low Light Auto Focus >This test is designed to measure the minimum amount of light under which >the >camera can still focus. The focus target is our lens distortion test chart >(shown here on the right), camera is positioned exactly 2 m (6.6 ft) away. > >Light levels are gradually dropped until the camera can no longer focus. >Before the shutter release is half pressed the lens is manually focused to >the closest subject distance (typically 0.5 m) to "throw the focus out". >This test target is the optimum type of subject for most AF systems (as it >has a vertical line at its center). > >AF assist via flash > >The *ist D implements an AF assist function using the built-in flash (this >is much the same as Canon's EOS 10D). To use the AF assist feature you must >first pop-up the built-in flash unit, upon half-press of the shutter >release >the camera will strobe the flash in order to illuminate the subject. In our >tests the *ist D required two attempts to get a good lock and the entire >process (from half press to locked) could take up to three seconds. > >The other disadvantage is that there appears to be no way to stop the flash >from firing once up so you can't for instance use the flash for AF assist >and then take a normal long exposure (without pushing the flash back down >again manually). > >Results without AF assist > >... > >As expected faster lenses performed better (because more light is getting >through to the AF sensor). In low light situations the *ist D's AF system >did seem to take a few spins of the AF motor to get the lock just right, >thus the 2.5 - 3.5 seconds to focus. > > > >Jens Bladt >mailto:[EMAIL PROTECTED] >http://hjem.get2net.dk/bladt > > >
