Ghosting?

[myplace46 0]

Hey guys,

the other day after I finished up installing one of my cameras, I was very pleased with the IQ. I was really surprised I could

read the street sign on the corner a block away when I zoomed in. Then a couple hours later I came back, and

the image was a bit blurry. When I zoomed in I could see a definite ghosting in the image. This seems to be across the board on all my cameras but, shows up more on cameras where I can zoom in. Previously, I just thought that was the best I could expect form analog cams but now I can see there must be another problem. If anyone has any suggestions, I'd love to hear them.

Thanks,

John

[the toss 0]

Ghosting is usually the result of impedance mismatch. What type of cable are you using ?

[myplace46 0]

Ghosting is usually the result of impedance mismatch. What type of cable are you using ?

 

Hi,

I'm using RG59 Siamese copper core, 95% braid.

That should be sufficient shouldn't it?

Thanks,

John

[dolladave 0]

Have you verified that your cable and BNC connectors are rated for 75ohms? I bought a pack of 40 BNC compression connectors off of ebay awhile back and found out the hard way after the install was done that I had a similar issue. As it turned out, my BNC's weren't rated for 75 ohms...

 

On a side note, are they bullet/dome cams with IRs or box cams using IR illuminators? You said it was fine and came back a couple of hours later and it was a bit blurry? Was it daylight when it was fine and darker outside when they were blurry? If so could be an issue of focus shift with the cameras not having IR corrected lenses.

[myplace46 0]

Have you verified that your cable and BNC connectors are rated for 75ohms? I bought a pack of 40 BNC compression connectors off of ebay awhile back and found out the hard way after the install was done that I had a similar issue. As it turned out, my BNC's weren't rated for 75 ohms...

 

On a side note, are they bullet/dome cams with IRs or box cams using IR illuminators? You said it was fine and came back a couple of hours later and it was a bit blurry? Was it daylight when it was fine and darker outside when they were blurry? If so could be an issue of focus shift with the cameras not having IR corrected lenses.

 

Hey Dave,

That's a really good question. How would I find out? I got these BNC connectors several years ago when we moved into a new location at work.

I went through the building and collected about a hundred of them that were left from the previous occupants. Its what they used for there computer network system.

As for the cams, I have a variety of box cams plus the one PTZ dome. Its a Toshiba IK-DP30.

Lighting isn't an issue. I've played around with focus and iris to no avail. At first I thought it might be the camera but realized it a problem across the board. I'm starting to question if it might be the signal passing through my DVR... I guess the best way to check that would be to hook it up directly to my monitor. I'll do that and let you know what I find out.

Thanks,

John

[Soundy 1]

10base-2 networking used 50-ohm RG58 cable... the BNCs are probably rated 50 ohms as well.

[dolladave 0]

I don't honestly know of there is a way to check the connector or not. I just know after completing an install I was disappointed in the results and went through everything trying to resolve it. I finally bought a pack of connectors that I knew were 75ohm and put a new BNC on each end and it fixed that particular camera. I emailed the ebay seller to ask him about it and he told me that the connectors I'd purchased from him were in fact 50ohm even though the listing didn't state it. Ended up having to replace connectors on 10 different cameras.

 

Dave

[myplace46 0]

Well...

That sounds disappointing. although, if that is the problem it will be easy enough to fix.

I'm curious though why it would be OK at first then degrade later? Oh well.

I still haven't had a chance to check things out by connecting directly to the monitor yet, its

not as easy with my set up as one might think.

[tomcctv 190]

hi. john which type of power supply are you using. you can also get ghosting from a power unit ..... if it a all in one i.e 8- 16 way. then start by taking the nutral off from each camera and see if it goes

[SEANHAWG 1]

Wiggle your connectors to see if it clears it up while wiggling.

[myplace46 0]

Sean, tried that... didn't seem to help.

 

Tom, I'm using an Altronics 24vac 16 position supply. I'm not getting it, if I take of the neutral wire, it won't work.

[shockwave199 0]

Maybe this is speaking more towards the dvr itself. What dvr is it? If this is a problem across the board the whole time and you're just catching up to it because of zooming- it could very well be the dvr, no? And what monitor are you using?

[myplace46 0]

Maybe this is speaking more towards the dvr itself. What dvr is it? If this is a problem across the board the whole time and you're just catching up to it because of zooming- it could very well be the dvr, no? And what monitor are you using?

 

Hey Shock,

Yeah, could well be. I just haven't had the time to check it out further.

I was waiting for payday to pick up some 75 ohm BNC connectors and try running a cable strait to my monitor to see if there was any improvement.

I'm using a 32" HDTV for my monitor, is that acceptable?

Thanks,

John

[tomcctv 190]

Sean, tried that... didn't seem to help.

 

Tom, I'm using an Altronics 24vac 16 position supply. I'm not getting it, if I take of the neutral wire, it won't work.

 

 

 

sorry John. i ment neutral as in - of each camera 1 at a time.

[shockwave199 0]

Maybe this is speaking more towards the dvr itself. What dvr is it? If this is a problem across the board the whole time and you're just catching up to it because of zooming- it could very well be the dvr, no? And what monitor are you using?

 

Hey Shock,

Yeah, could well be. I just haven't had the time to check it out further.

I was waiting for payday to pick up some 75 ohm BNC connectors and try running a cable strait to my monitor to see if there was any improvement.

I'm using a 32" HDTV for my monitor, is that acceptable?

Thanks,

John

I would try one at a time- first try running a line straight to the monitor and see. Then try the bnc. But not both at the same time. You never know what something is changing TWO variables at the same time. Far as the 32" tv, I don't know. I've never used tv's to monitor. Someone else will have to chime in on that one. Good luck.

[dolladave 0]

I'm using a 40 inch Samsung that's a plasma for my general viewing. Its connected via the BNC out to RCA on the TV. It works but the quality isn't the greatest. I've got a 20 inch flat screen computer monitor I use for viewing the specifics. It's quality is superb. My TV doesn't have a DVI input so I couldn't tell you the difference in quality on a 32+ screen using the proper cabling.

[Soundy 1]

How are you connecting the DVR to the smaller monitor? Doesn't the big one have HDMI or VGA inputs?

[dolladave 0]

The DVR has a VGA out and a BNC out. My television doesn't have a VGA input. So the DVR goes BNC to RCA at the TV. And vga from the DVR to my computer monitor. I use the TV for general viewing but if I need specifics I just switch on the computer monitor and view on it since the quality is a lot better.

[wezard 0]

IBM, and some others used to use 92 ohm for token ring and LAN networks. Might still do for high security networks, but I haven't seen it in 12 - 14 years.

Europeans used 60 ohm for broadcast at one time, but that was way back, doubt you ran across that in a state side office bldg.

 

You really need some way to go straight from camera to monitor with known good connectors, disconnect everything, start at the camera, then connect each piece one at a time. Any chance of laying your hands on a scope?

 

My money is on 92, (or 50 ) ohm connectors, but I'm not betting big. Could be a ground loop issue. Again, you need to disconnect EVERYTHING, start with one good signal and reconnect one cable/device at a time till the problem presents, that includes power.

[J-Telectro 0]

Hi John,

 

If your cameras gave good video when you first installed them then it doesn't

sound like a problem of 50 ohm vs 75 ohm connectors. If it was a problem with

regard to the connector type it would have been there from the beginning.

 

It's possible that the connector dielectric could be defective but that would be a long shot.

Or you might have a problem with the actual connection between coax and connector.

 

But first,

Have you had rain or high humidity there? I've had a similar experience with high

humidity and condensation on or inside the camera lens or camera housing.

Also could you have moisture in the connectors or coax?

 

The best thing to do is what other posters have suggested. Connect 1 of the bad cameras directly

to your monitor or tv and see what you get. If it looks good add components until it messes up.

That way you can break it down into manageable pieces rather than just guessing and changing

things at random.

 

Good luck!

John

[myplace46 0]

Hi guys,

Sorry to take so lone to get back, been real busy.

I'm grateful for all the feedback.

I finally got around to connecting my cams without the DVR in the mix... no luck there.

Next step is to try new BNC connectors. Its a two man job to safely take down the camera

I'm having the biggest problem with so, I have to wait for some help.

I looked at some BNC connectors at Home Depot today but, there is nothing to indicate if they are 50 or 75 ohm...

anybody have a favorite supplier?

John

[myplace46 0]

Well...

I did a little research on line and now I'm 99% certain I have 50 ohm connectors.

I just ordered a box of 100 75 ohm so, as soon as they come I'll start changing them out.

I'll let y'all know how that works out.

Cheers,

John

[shockwave199 0]

Fingers crossed that does it. How's that ptz up on your custom pole doing for you in general?

[myplace46 0]

Fingers crossed that does it. How's that ptz up on your custom pole doing for you in general?

 

Hey Shock,

over all, I love it! I can read the stop sign a block and a half away (even with a blurry image) as soon as I get things working properly I'll post some images. I also just got my Pelco pan tilt unit installed with my 8-80mm motorized lens and that's working real well too.

I just got home from work and found my DVR has gone on the fritz! Oh well, that gives me a good excuse to buy that hybrid unit I've been wanting. seems if it weren't for bad luck, I wouldn't have any at all.

Have a great week end,

John

[myplace46 0]

OK, new update...

I had a couple baluns on hand so, I decided to try them.

Much better but, still a bit of ghost only, now its side to side, before it was up & down.

Anyway, wish I had known about baluns before, I would have run all my cams that way and saved some money.