GiovanniG 0 Posted November 25, 2020 Hi mates, thank you for your kind attention, I hope to find someone here who knows how AHD works and how many chances I have to solve this problem: To help a friend broadcating his businness I bought for him some unexpensive Dahua Cameras, they are varifocal and suite perfectly what he's planning to do, I've bought also a video aquire tool from AHD to USB3 (4 channels, 720p). SInce the datasheet declares AHD output as possibility I bough with confidence.. an analog camera teorically is "stupid as possible" so the signal will not be manipulated, just the transmission change.. but actually not, Dahua found a way to worse its video signal AHD probably for not being convenient to buy without a CVI dahua recorder. Strange because TVI keeps the same quality of CVI.. and TVI is its main competitor Hikvision.. so why? I hope an hardware issue. I've made these tests using a Dahua XVR, with PTZ menu I canched the output, and as you see even the OSD become unfocused. It looks an horizontal signal reflection on the right, but it can be a downscale of the lines, maybe, like it happens with 1080N for example. What do you think? There is anything to put on cable (like a termination resistor) to solve this? There is any way to convert externally a CVI to AHD? Do you have any documentation describing the 2 standards? Thank you a lot for your considerations Share this post Link to post Share on other sites
tomcctv 187 Posted November 25, 2020 Hi. Which cameras are you using ? why only on 720 Share this post Link to post Share on other sites
GiovanniG 0 Posted November 26, 2020 Thank you for your kind help, the model is HDBW1100RP-VF-S3, I don't think it matters a lot.. I would more focus on the possible cause and how the video signal differs from AHD to CVI, thank you. The reasonable price for a converter 4ch was only for 720p, and for me a real 720p is enough.. Share this post Link to post Share on other sites
