Return-Path: X-Original-To: u7f01aa@mail.lrz-muenchen.de Delivered-To: u7f01aa@mail.lrz-muenchen.de Received: from lxmhs13.lrz-muenchen.de (mailha13.lrz-muenchen.de [129.187.254.31]) by mailin.lrz-muenchen.de (Postfix) with ESMTP id 5F3B46A8FF for ; Mon, 26 Sep 2011 18:21:50 +0200 (CEST) Received: from mailrelay2.lrz-muenchen.de (mailrelay2.lrz-muenchen.de [129.187.254.102]) by lxmhs13.lrz-muenchen.de (Postfix) with ESMTP id 4EA0B80A233 for ; Mon, 26 Sep 2011 18:21:50 +0200 (CEST) Received: from scan3.mail.lrz.de (scan3.mail.lrz.de [10.156.6.37]) by mailrelay2.lrz-muenchen.de with ESMTP for Hans.Strasburger@lrz.uni-muenchen.de; Mon, 26 Sep 2011 18:21:41 +0200 X-Virus-Scanned: by amavisd-new at lrz.de in 37 X-Spam-Flag: NO X-Spam-Score: 2.246 X-Spam-Level: ** X-Spam-Status: No, score=2.246 tagged_above=-999 required=5 tests=[AWL=-0.094, BAYES_50=0.8, DATE_IN_PAST_06_12=1.543, LRZ_FROM_PRE_SURa=0.001, LRZ_HAS_IN_REPLY_TO=0.001, LRZ_HAS_REFERENCES=0.001, LRZ_HAS_SENDER=0.001, LRZ_MSGID_APPLE_MAIL=0.001, LRZ_MSGID_FROM_DOMAIN=0.001, LRZ_XM_APPLE_MAIL=0.001, T_RP_MATCHES_RCVD=-0.01] autolearn=disabled Received: from mailrelay2.lrz-muenchen.de ([10.156.6.1]) by scan3.mail.lrz.de (scan3.mail.lrz.de [10.156.6.23]) (amavisd-new, port 10024) with ESMTP id O-Ayc1MD8VSo for ; Mon, 26 Sep 2011 18:21:40 +0200 (CEST) Received: from postrelay2.lrz.de ([10.156.6.209] [10.156.6.209]) by mailrelay2.lrz-muenchen.de with ESMTP for Hans.Strasburger@lrz.uni-muenchen.de; Mon, 26 Sep 2011 18:21:40 +0200 Received: from lawton.ewind.com (lawton.ewind.com [68.166.223.203]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by postrelay2.lrz.de (Postfix) with ESMTPS id D8FA22400084 for ; Mon, 26 Sep 2011 18:21:37 +0200 (CEST) Received: from lawton.ewind.com (localhost.localdomain [127.0.0.1]) by lawton.ewind.com (8.13.1/8.13.1) with ESMTP id p8QFIt3b011601; Mon, 26 Sep 2011 08:18:55 -0700 Received: (from majordomo@localhost) by lawton.ewind.com (8.13.1/8.13.1/Submit) id p8QFItmj011600; Mon, 26 Sep 2011 08:18:55 -0700 X-Authentication-Warning: lawton.ewind.com: majordomo set sender to owner-cvnet@lawton.ewind.com using -f Mime-Version: 1.0 (Apple Message framework v1084) Subject: Re: CVNet - An LCD monitor for research in vision From: Michael Bach In-Reply-To: <201109250752.p8P7quMx024747@lawton.ewind.com> Date: Mon, 26 Sep 2011 09:40:29 +0200 Message-Id: <1BB5BA09-5E1C-4159-9148-C265D1EC944A@uni-freiburg.de> References: <201101271623.p0RGNqOW031498@lawton.ewind.com> <201109250752.p8P7quMx024747@lawton.ewind.com> To: CVNet CVNet X-Mailer: Apple Mail (2.1084) X-NAI-Spam-Flag: NO X-NAI-Spam-Threshold: 5 X-NAI-Spam-Score: 0 X-NAI-Spam-Report: 1 Rules triggered * 0 -- RV3991 X-NAI-Spam-Version: 2.2.0.9286 : core <3991> : streams <685234> : uri <968827> Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by lawton.ewind.com id p8Q7eeFE007459 Sender: owner-cvnet@lawton.ewind.com Precedence: bulk Dear fellow CVNetters interested in visual display units: I bought a Samsung SyncMaster 2233 on Danko's recommendation. Yes, nice monitor, but: This one and _all_ LCDs I looked at and heard about suffer from luminance artifacts due to asymmetric hi-lo switching delays. Just display a checkerboard (even number of checks, and centered) and reverse check contrast: there should be no net change in mean luminance, but there is a brief transient artifact. Depending on contrast, this can be a brief increment or decrement. Easily seen by placing a white sheet moderately close to the display and observing it while the stimulus reverses, ideally at about 10 reversals per second. Such pattern-reversal stimuli (which are unfortunately often termed "flicker stimuli" in the fMRI literature) thus actually do flicker, totally unacceptable for many of my applications. Best, Michael. -- Prof. Michael Bach PhD, Ophthalmology, University of Freiburg, Killianstr. 5, 79106 Freiburg, Germany. President of ISCEV Visual illusions: ------------------------------------------------------------------- To get information on using CVNet, send a note to: majordomo@mail.ewind.com In the body of the message, enter: info cvnet