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Post by Deleted on Feb 12, 2014 15:47:57 GMT
Hey all,
I could sure use some help sorting out the monitor issue. I'm electrics/electronics challenged and trying to sort this out is badly bending my bitty-brain. My objective is hosting outreach events in the field (no A/C). I want to present the best views to the public. And, I don't have "deep pockets".
Over on the MC group site, is see reference to Rock's new S-video/HDMI converter Product . So, this takes S-video or composite and transforms it into a higher definition/resolution signal. If I'm right so far, the HDMI signal will give the best possible (Wow factor) resolution views for larger screen HD monitors for group viewing? At the same time, I'm hearing some members saying composite is superior to HD. But, larger monitors require A/C. Are there larger monitors that can run off DC?
I'm hearing good things about using a 7 inch TFT Color LCD Car Rear View Camera Monitor at Amazon.com: www.amazon.com/Camera-Monitor-Support-Rotating-Screen/dp/B007SLDF7O These pups are on the order of $35, plus needing a few doo-hickies to connect to a power tower. I would use this to fine tune focus at the scope, make sense? But, this would be pretty small for outreach. So again, I'm wondering if I don't need a larger monitor for the public.
OK, there's one more gizmo, a SVA4 Video Signal Amplifier with Single Video Source Input and 4 Video Outputs at Amazon: www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Delectronics&field-keywords=Sound%20Storm%20Laboratories%20SVA4%20Video%20Signal%20Amplifier%20with%20Single%20Video%20Source%20Input%20and%204%20Video%20Outputs%3A%20Car%20Electronics%2C%20 It's only $11 plus an adapter for the 12 VDC input.
So, what I need to do to get it all together is video out at the camera, to the Video Signal Amplifier, split one S-video line back to the small monitor at the scope and the other to the HDMI converter which connects to the HD monitor? Or, would you try going with composite/S-Video before popping for the HDMI converter? And, is this the most cost effective and highest quality course to achieve my objective in paragraph one, above?
What would you do in my shoes?
Thanks, and clear skies...Bob
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Post by Deleted on Feb 12, 2014 16:09:11 GMT
Hi Bob, if just splitting the video feed into two you shouldn't need an amplifier just a passive two way splitter.
I would try Composite first see what its like, personally I would say HD will be even better.
Regarding monitors, what sort of power source are you using, If a 12V battery what sort of Ah is it rated at?
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Post by Deleted on Feb 12, 2014 16:23:32 GMT
Hi Carl, thanks for the "come-back".
A two way splitter, eh? That's worth a try. Makes sense to try the composite first, you're right.
I have a 17 amp power tower, figured I'd use that at the scope for the camera and focus monitor. I also have a 12 Volt 35 Amp Hour deep cycle battery. Hmmm, that might work at the group viewing monitor with an inverter (converter?). Is that your thought here?
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Post by johnno on Feb 12, 2014 16:55:05 GMT
Bob how about a projector, the image wont be as sharp but a lot of people can view it at the same time.
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Post by johnno on Feb 12, 2014 17:26:22 GMT
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Post by Deleted on Feb 12, 2014 18:36:03 GMT
Hi bob Inverters are not that efficient in power conversion. Although they do work they suck a lot of Amps from the battery and a 35Ah may last only a few hours. I think if you require say 100W of power from a 12V battery it will draw around 9 Amps from the battery, 200W then 18 Amps. If you could get a 12V 100Ah battery much better. Better still a small generator would be handy and last as long as you need, but a bit of noise in the background. Over all it does depend how long your out and what power you need
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Post by Deleted on Feb 12, 2014 20:10:05 GMT
Good idea John, I'll be looking into video projectors now. I have an email off to SCDVA.
Carl, I'm following you as regards power requirements. Had an Honda 1000 W generator and it was quiet, but then you have exhaust fumes. I'll keep digging on this.
Thanks guys!
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Post by Deleted on Feb 12, 2014 20:10:17 GMT
Good idea John, I'll be looking into video projectors now. I have an email off to SCDVA.
Carl, I'm following you as regards power requirements. Had an Honda 1000 W generator and it was quiet, but then you have exhaust fumes. I'll keep digging on this.
Thanks guys!
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Post by Deleted on Feb 13, 2014 11:01:03 GMT
A broadcast quality monitor will be superior to any comercial grade monitor. Look on ebay and search fot " broadcast quality monitor" as for a splitter it will work but it will reduce dynamic range slightly.
Upscalers do not make the image hd quality, they just upscale the resolution to work on an hd moniter. Digital enhancements may improve image some, but it will not make a night and day difference imo.
A good broadcast quality monitor designed for native camera resolution will look better IMO
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Post by Deleted on Feb 13, 2014 13:40:14 GMT
Hemmi, your suggestion is "Golden"! Thank you! eBay does have a good selection of used professional grade monitors, and I'll go that route. At least one of them is 12VDC/120VAC.
By "splitter" are you referring to an inline RCA "Y" splitter, that is one to two? Or, are you referring to the unit I mentioned in the OP?
Rock's upscaler is said to change the native screen level to 1080 lines or whatever they are. Would this be a factor to consider? Or, does this refer only to an HD screen quality/spec? IOW, by getting a Pro grade monitor, will that be as good as it gets?
Thanks again...Bob
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Post by Deleted on Feb 13, 2014 13:50:04 GMT
Bob how about a projector, the image wont be as sharp but a lot of people can view it at the same time.Thanks John! Got a nice reply from Tom at SCDVA:Hi Bob, Based on what you're saying, great results with any projection are nearly impossible. Light pollution just kills the benefits. High lumen dlp or led projectors have gray levels that just blow out images and blind the stargazing audience. Even high contrast units will amplify the LP. Some high end plasma flat screens will do much better, but LP is still the issue. Simply put, the Mallincam wants dark skies and need them for any effectiveness with big screen presentation. We are lucky to be in good skies or we wouldn't get the results we do. I think you can try any average dlp projector to see what you get, but the LP is going to limit the outcome. CRT projectors give better contrasts but rely on dark to function as they are so low in lumen output. That's what killed them as you need a dark room to even watch movies, besides weighing a ton or two and having convergence issues when moved around. Last issue is a power source that can run the stuff. One thought that brings a sense of functionality is the add on iPhone projector that is fun in general and gets okay results with internet stuff too. Anyway, we need to fix the night sky and that's about it. Hope this helps. Best Tom Bottom line is unless we have a really dark site like the SCDVA, projection isn't the answer. Nice to know this...
Bob
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Post by Deleted on Feb 14, 2014 21:35:46 GMT
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Post by johnno on Feb 15, 2014 1:28:11 GMT
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Post by johnno on Feb 15, 2014 17:03:41 GMT
I'm still going to go down the projector route, broadcast crt's gives a better images but even a small 10 inch one can weigh a ton and everyone will be crowded around it trying to have a look, it will be like looking at laptop, I think there has to be a trade off between the two,
Projector, small portable, 12 volts or mains, light weight, bigger screen up to 60 inches,can be placed anywhere for viewing. uses less power
broadcast crt, heavy, better image quality, 12v or mains, to small for crowd viewing
One guy was using one at one of our outreach sessions, nothing fancy it was a Epson projector and a 60inch screen, he had it setup about 10ft away from his scope so people would not be gathering around his setup, bottom of the screen was about 5 ft from the ground and everyone could see from most of the carpark. I was 30 ft away with my setup and had no problems looking at it from there. Only thing was he was doing Lunar views with it, if it was DSO's that might be not as good.
I'm keeping a look out for a dirt cheap one to experiment with and try it on my white garage door when I get round to washing it down. I wonder what it would look like on a black screen?
www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/6092375/Main/6089336
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Post by Deleted on Feb 15, 2014 20:14:52 GMT
I have a projector laying around not being used. When I get a chance I will give it a try and see. I can imagine a 640x480 mallincam image of a dso stretched to 50 inches would look terrible. Stars would look like awful IMO. From 50ft away it might look ok. With a nice HD cam on the moon I think it would look great.
I would borrow or rent a projector and try it out before you buy, as you may be disappointed.
If outreach is your goal, it would be the bet bet. The smaller the projected image the better it will looks. If using a cam such as the sammy or mallincan try keeping the size down to about 40" and about about 15ft away from viewer for best image. Contrast and dynamic range is terrible on inexpensive projectors (and all projectors to be honest) so be prepared for dim objects to be washed out. Try sticking to lunar,planetary, or bright nebula like m42 etc.
Don't let the above discourage you, just be aware of the limitations.
I will give it a try when I get a chance and report back. But seeing as im in recover from surgery, it will be a few weeks.
Hemmi
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Post by davy on Feb 15, 2014 20:33:14 GMT
Yeah have to agree with hemmi going large would look amasing but lose a lot of definition but if you went 30" large enough to show an audience but small enough to hold a more detail and colours would jump out the screen at you...
Hope recovery is swift hemmi...davy
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