On Wed, 17 Apr 2002 16:10:00 Julian Loke http://groups.yahoo.com/group/elan7e/files/Julian%20Loke/aftest.htm
This file is an attempt to provide a standard target for testing Autofocus sensitivity. When you display it in a web browser, you can see that there are a series of grey patches on the left half of the screen, on top of a black background. With an EF 50mm f/1.8, the Elan 7E meters the black near EV 0 (= 2" @ f/2), and the 255 white patch near EV 9 (=1" @ f/22). This is a 10 step difference, enough to make a meaningful test. The test area is the sharp transition between the light patch and the black patch. Scroll up and down the page and test if the camera is able to lock onto the transition. Of course, the AF assist beam has to be disabled to make comparisons meaningful between different cameras. Record the spot or partial meter reading for BLACK, and the reading for WHITE, and the patch number, as well as the meter reading over the patch. For instance, My Elan 7E is able to AF down to patch numbered 65, with some hunting. . Black = 1"@f/2.8, . White= 1"@f/22, . Patch 65= 1"@f/8 I welcome others to compare their results, and post them here. Does the EOS A2E perform as well? How about the EOS 3? Or the D30? Or the 1V? I will collate the results for eosdoc. Hi Julian, I did a quick test on a range of cameras (Canon and Nikon) and there are some interesting results. I didn't make a note of the exposure values, but all were done at the same time of day (+ or - 10 minutes) and provide a RELATIVE measure of the low light AF ability of 6 cameras. Of course is doesn't measure AF speed, but is nonetheless useful. The cameras: - Canon: EOS 3, EOS 30 (Elan 7e), EOS 55 (Elan IIe) - Nikon: F801s (N8008n), F80 (N80), F65 (N65) To keep it equal the Canons were fitted wih a Canon 50mm f1.8 Mk1 and the Nikons with a Nikkor 50mm f1.8. All were using centre AF point and no AF assist (not that it would help). The results were (best to worse): 13 - EOS 3 14 - F801s 16 - F65 18 - EOS 55 and F80 22 - EOS 30 So while the EOS 3 was a winner, it was close. The F801s focused on #14 every time, but wouldn't focus on #13 at all. The EOS 3 was the same with #14 and usually made focus on #13 and not at all on #12. Given that the F801s is a 10 year old camera, it's an impressive result. The EOS 30 clearly trailed the field, giving credence to the general opnion that has less capable low light AF ability. Of course AF ability in better lighting, AF tracking ability etc are other things again. The differences in absolute values obtained between your Elan 7e and my EOS 30 are no doubt due to difference in monitor settings (maybe I need to turn mine down so that I don't fry my brain....) Regards Gary This mail has passed through an insecure network. All enquires should be directed to the message author. * **** ******* *********************************************************** * For list instructions, including unsubscribe, see: * http://www.a1.nl/phomepag/markerink/eos_list.htm ***********************************************************
