jonnybrandon Posted August 29, 2009 Share Posted August 29, 2009 Hello everyone. Long time lurker, first time post. Thank you for all the (indirect) help over the last couple of years. I am currently winging my way through video designing and projection operating for a mid-scale show that will be touring next year. I am relatively comfortable with the production side of things, but the output is giving me a major headache. I am getting a poorly defined image from the projector, which is a brand new Optoma EP781. It is a hardware issue and I just need somebody to tell me "this is what you need". My current set-up is as such: Macbook Pro to VGA-analogue converter (resolution 1280x1024)* to old but reliable VMX400 Mixer** (Inputs: 2 x Composite/S-Video, Outputs: 1 x S-Video, 1 x Composite) to S-Video Line Driver to XGA Projector*** via 20m quality s-video cable. * I can go into the mixer via either composite or S-Vid, at the moment I am sticking to S-Vid.** The reason I am using a mixer is because at various points during the show I need to mix different feeds from a live camera on stage and a DVD player with my Mac feed.*** I am projecting from the grid from approx 10m onto a cyc with image approx 4m x 5m. When I am inputting straight from the live feed through the mixer to the projector, the image is good (surprisingly so, considering the distance etc) but when I am inputting from my Mac the image is ending up fuzzy, as if slightly out of focus, even though the proj is set up to optimum sharpness and focus. I'm sure this is to do with resolution and signal restrictions, but my head is in a spin and I can't work out what I need to do. Is it because I am running everything by S-Video? If I could output straight from my mac via VGA to projector, I would be a happy bunny but unfortunately I have to incorporate this mixing desk. Do I need to place an S-Vid to VGA Converter between the mixer and the proj and run VGA instead? Any help whatsoever would be gratefully received, as I've been in rehearsals trying to sort this out for three weeks now and I've not got anyone who knows better here! Thanks for reading and thanks in advance for any tips/advice.JB Link to comment Share on other sites More sharing options...
kitlane Posted August 29, 2009 Share Posted August 29, 2009 It certainly sounds like it's a resolution/signal issue. Your scan converter is taking the 1280x1024 signal and effectively downscaling it to standard definition analogue resolution which is kind of equivalent to 720x576 (I am simplifying here) resulting in a fuzzy image. You are right to choose S-video over composite; it separates the Y (luma -brightness) and the C (chrominance - colour) information and gives a much cleaner image than composite. Converting the S-Vid to to VGA is unlikely to improve matters. Converting from one resolution to another will always introduce some 'distortion'. You could try running the Mac at a resolution closer to Standard Definition (800x600 if it won't do 720). This might reduce the scaling distortion and make the image clearer. To be honest, scan converting the VGA and running it through a mixer is always going to be disappointing. Can the MacBook content be pre-rendered onto DVD? Can you run a video mixer or VJ type app on the MacBook and take the live feed into the Mac? Link to comment Share on other sites More sharing options...
jonnybrandon Posted August 29, 2009 Author Share Posted August 29, 2009 Thanks for your reply, glad I am at least doing things a little bit right. Will try toggling my output resolution on Mac. Yes I can burn everything to DVD, in fact that's what I did last time and it seemed to work better - wanted to avoid it this time, though, so I don't have to re-render everything whenever a change occurs. Might try that if all else fails. Link to comment Share on other sites More sharing options...
Pete McCrea Posted August 29, 2009 Share Posted August 29, 2009 The other option is to scale the camera and DVD to the native resolution of the projector and mix the feeds in a scaler swicher. This will keep the PowerPoint looking crisp and depending on the quality of scaler could make little difference to the live feed and DVD. My preference would be something from Barco/Folsom. But I'm also hearing a lot of good things about the TVOne products at the moment. In terms of cost the cheapest way is as kit says and to try and keep the resolutions as close as possible. Feel free to PM me if you want more help. Link to comment Share on other sites More sharing options...
lobba Posted August 30, 2009 Share Posted August 30, 2009 Get yourself one of these and get rid of any third party scan converters, unless you spend quite a lot of money on something like an ImagePro you're onto a loser. http://store.apple.com/uk/product/M9267G/A...;mco=Nzk2MDk4OQ Using this adaptor your mac will automatically switch to PAL or NTSC (your choice) and the composite will go straight into your mixer. If you are using Keynote on your Mac it's a good idea to set the slide size to either PAL or NTSC too, again avoiding another point of scaling. Ideally with any video/data distribution you want to keep the resolution the same at as many points as you can, it's generally the scaling that softens your image, especially scaling down. Hope that helps. Lobba Link to comment Share on other sites More sharing options...
jonnybrandon Posted August 31, 2009 Author Share Posted August 31, 2009 Wow, thank you - had no idea Apple did these. Cheap as well! I will be using a combination of Keynote/Powerpoint and video files, probably via Niceplayer or the like. Therefore, should I still set my output monitor display to 720 (or as close as it will get)? Link to comment Share on other sites More sharing options...
jonnybrandon Posted August 31, 2009 Author Share Posted August 31, 2009 Thank you for all the help - I changed my resolution as suggested, to closer to the standard definition, and it worked, improving the image quality. Am going to look into changing to HDMI instead of S-Video for touring. Link to comment Share on other sites More sharing options...
kitlane Posted August 31, 2009 Share Posted August 31, 2009 Thank you for all the help - I changed my resolution as suggested, to closer to the standard definition, and it worked, improving the image quality. Am going to look into changing to HDMI instead of S-Video for touring. I'm not sure how you will integrate HDMI into your setup and what advantage it will give. HDMI carries a digital signal that is electrically compatible with DVI. You can transmit HDMI over copper for about 12-15m - with a booster you can get maybe 50m. However, if you still have the analogue video mixer then you will still need to convert the HDMI to analogue which will be no better than converting the DVI/VGA to s-video. Link to comment Share on other sites More sharing options...
jonnybrandon Posted September 2, 2009 Author Share Posted September 2, 2009 Ah, okay - HDMI probably won't be an option then. Thanks. Having fixed my projector focus issue, I am now having a different problem, this time with my live feed. The live feed is coming from an old compact hi-8 camcorder to my operating position via S-Video cable (again, best of a bad bunch of options). The actual image is decent, but it is vibrating, as a whole, from side-to-side (is this the same as 'jitter'?) for no apparent reason. It is constant and is not to do with the operator's hand shake, although it looks the same. Happening even when on a tripod. Obviously when the image is being projected onto a cyc, it is huge, and so it looks awful. I think it is a signal issue and is easily resolved but nothing I've tried so far has worked. Any ideas? Could it be interference from other sources (it is travelling a long way, and at one point crosses some LX cabling and XLR)? Thanks for any help. Link to comment Share on other sites More sharing options...
Robin D Posted September 2, 2009 Share Posted September 2, 2009 Bring the camera close to the desk and connect via a normal length cable to see if you get the problem while on a tripod at the same zoom ratio. If you do it's the camera or the mixer, else its the long cable as you suspect. At least this will prove you are dealing with the right problem. Check the pin outs on the long cable match exactly those on the short test cable. Where it crosses other cables try to screen it from the other cables. Alternatively invest in a couple of baluns and run it over CAT5. Anything over about 100ft is bound to give you problems with S-Video especially in an electrically noisy venue. Robin Link to comment Share on other sites More sharing options...
kitlane Posted September 3, 2009 Share Posted September 3, 2009 Ah, okay - HDMI probably won't be an option then. Thanks. Having fixed my projector focus issue, I am now having a different problem, this time with my live feed. The live feed is coming from an old compact hi-8 camcorder to my operating position via S-Video cable (again, best of a bad bunch of options). The actual image is decent, but it is vibrating, as a whole, from side-to-side (is this the same as 'jitter'?) for no apparent reason. It is constant and is not to do with the operator's hand shake, although it looks the same. Happening even when on a tripod. Obviously when the image is being projected onto a cyc, it is huge, and so it looks awful. I think it is a signal issue and is easily resolved but nothing I've tried so far has worked. Any ideas? Could it be interference from other sources (it is travelling a long way, and at one point crosses some LX cabling and XLR)? Thanks for any help. This is probably a crazy suggestion but does the camera have an anti-shake feature? If so, maybe it's not working properly. The other thing to try is plug a trusted video source (another camera, portable DVD player?) into the cable and see if the problem remains. Link to comment Share on other sites More sharing options...
jonnybrandon Posted September 3, 2009 Author Share Posted September 3, 2009 Thanks for the help again guys. Sorted it now. Kitlane, you're right, when I turned the anti-handshake function off, the vibrating stopped! After a while of shooting and moving around, it seems to get stuck in a loop of correcting itself - so we're just going to leave it off. Only trouble now is that the actors can't keep their hands steady enough! I will be doing all the common sense stuff like shielding from other cabling etc as well. Thanks again. Link to comment Share on other sites More sharing options...
TomHoward Posted September 4, 2009 Share Posted September 4, 2009 Get yourself one of these and get rid of any third party scan converters, unless you spend quite a lot of money on something like an ImagePro you're onto a loser. http://store.apple.com/uk/product/M9267G/A...;mco=Nzk2MDk4OQNot trying to cause trouble but just in case anyone is purchasing you might need to check the output port on the Mac, as the G5s are DVI, but some of the more recent ones are different. Link to comment Share on other sites More sharing options...
sleepytom Posted September 4, 2009 Share Posted September 4, 2009 the new unibody macbook pros have only a displayport connector which is not compatible with the apple svideo dongle. these machine need a scanconverter - ideally you want a scanconverter with DVI inputs such as a folsom imagepro, but you can use the apple VGA dongle and a standard VGA scaconverter such as the sony dsc1024g Link to comment Share on other sites More sharing options...
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