J-Telectro

Please forgive some of my crazy questions, but I am still new to this. I'm trying understand how to compare the light sensitivity of various cameras based on the manufacturers specifications. 1. What does the AGC value mean? Is this the amount of boost in gain for a given light level? For instance does an AGC value of 50db mean that the (voltage) gain from the sensor has been increased by a factor of 316? Then for an AGC value of 40db the (voltage) gain has been increased by only 100? 2. How does IRE relate to the light input in Lux? Is this a linear relationship? For instance if camera A = 50 IRE for 1 Lux and camera B = 30 IRE for 1 Lux does this mean that camera A would be 3/5 Lux for 30 IRE? How do you calculate the Lux value when you change from one IRE value to another? (This all assumes the "f" value for the lens remains the same)

Hi, I'm new to Cat5 cable and I'm trying to figure out the best way to connect multiple cameras without running unnecessary cable. Scenario 1- I want to put 1 camera in each of 4 bedrooms. The main cable run should go down the hall that leads to the bedrooms,and then each individual camera should have it's own pair from the Cat5 main cable. I could strip the sheath off the outside of the main cable where the first pair must exit and then run the other pairs individually to their respective rooms. Or I could try to cut the sheath where each pair must exit and then splice a second Cat5 cable for each room. Total run for the main cable is about 60 feet and the runs in the bedrooms are not over 20 feet. There is no access to the attic so these runs have to be made along the ceiling or baseboard. I can either run a separate power cable or try to power the cameras locally. What's the best way to do it? Scenario 2- Similar situation but I want to install 4 cameras outside along my fence. The main run will be about 125 feet to the first camera then I need to split off to the left and right to the other cameras. It will be about 75 feet in one direction and about 100 feet in the other (for 2 cameras). What about waterproofing if I make splices? Runs will be done in conduit underground but it is common here to have water standing in underground conduit and junction boxes according to electricians I have talked to. I also plan a separate power run. John

I was thinking about running them along the ceiling, where the ceiling meets the wall. I don't have an attic or a basement and the walls are plaster over metal lath. I really don't want to cut out channels in the plaster and then try to plaster over the cables. Now I'm thinking about Surface Raceway like Wiremold down by the baseboards but that is really expensive. John

I'll give that a try thanks! Yeah, I really need to rethink this. I need to find a better route for the cables. Thanks. One other question..do the newer IP and Megapixel cameras use all 4 pairs in the cat5 cable? Thanks everyone for your help, it saved me from causing myself a lot of extra work. John

LOL! Actually they are pointing out the windows. The 4 channel balun and local power sounds good. I'd like to but that's a lot of ugly cable down the hall. I'm hoping that one run can be placed without making things look too bad. Outdoors that would work fine. For the outside installation that should work great.I was wondering about the proper way to do the secondary runs. Thanks everyone for the suggestions! Another question: Can you break the twisted pairs out of the main cable and run them individually for several feet? (Indoor installation). Will they untwist or suffer other problems with interference, impedance mismatch etc? Thanks, John

One word of warning... Don't assume that because the supply voltage to a device is low that the required input current also goes down. Most modern electronic devices use internal switching regulators and with these the opposite is true...as the input voltage to the device drops, the input current increases. As everyone has said make sure you have a supply that is rated for your device. John

Hi Jack, I checked the data sheet and the LTC0495 is specified for the same resolution for both color and BW. John

Hi Jack and Mike, The street light does give a good deal of light, the picture is a little dark and noisy but not bad. I'm still experimenting, I've tried it also in the auto mode but I prefer the color at night. I think the only way to switch the IR filter out is to go to BW. I am using 2 cameras to cover 2 cars that I have parked in front as Mike advised. Not a problem, I appreciate the help. Interesting you would suggest that, this weekend I went around looking for an old VCR or something that has the IR transparent plastic on the front,I hadn't thought about Ebay,thanks! I also tried some smoked and mirrored lenses from dollar store sunglasses but like plexiglass they weren't that great. I need to do that also. The BW performance of my 0495 is very similar to the LTC0355 except that with the default settings the 0495 is slightly brighter and noisier. I've only noticed a slight difference in resolution between the 2 at night as long as a person is fairly close. John

Hi Jack, Mike_VA knows about the Bosch cameras along with some of the more experienced installers on here. I'm also using an LTC0495 to monitor my driveway. I use either the X2 setting or Sensup off. The X2 does create some blurring.X2 and X4 make big improvements in a dark picture. I don't notice too much improvement above X6. The blurring/delay get pretty bad at X4 and above. You can test the effect of the Sensup settings by putting the camera in a dark place and waving your hand in front of the lens (as long as it is dark enough so the Sensup is active and you can still see your hand). I'm using my camera looking out through a window with a computer monitor anti-glare screen between the window and the camera to hide the camera from people outside the window. This decreases the amount of light to the camera but it is still adequate at night. I have a street light about 60 feet from the camera. I am currently using my camera in the color mode, both day and night. You can adjust the level at which it switches to the night mode. I think I am set at -15 but I'd have to check. I haven't noticed any effect on the low light performance with the BLC on, I leave it on all the time. Mike and others on here that have more experience than I do can probably help you more with these and other settings. The tripod is a good idea. I've been testing all my cameras in a housing mounted on a tripod. But I learned the hard way that you want to use a sturdy metal tripod if you can and not the weaker plastic ones! Best regards, John

LOL! Sounds like Sheldon on Big Bang Theory. But there is some truth in what he says. I repaired and calibrated blood analysis instruments for several years, both in the field and at a repair facility. When I started I didn't wear gloves or even wash my hands before eating. That was about the time that AIDS became well known. There were many times that we worked on equipment without gloves because we were lazy. No one that I worked with became ill in spite of our carelessness. When we got sick we always caught it from a friend, a family member, or someone that we came into contact with out in public. I'm more careful today, there are a few things I avoid: People sneezing or coughing on my food. Bowls of chips at parties where people touch everything in the bowl. Food that has fallen off the plate onto the table or counter at a restaurant. If I'm too lazy or can't wash my hands I eat sandwiches or burgers with a knife and fork at restaurants. I try to avoid enclosed areas where someone has been coughing or sneezing. If I've been out somewhere I wash my hands before touching my face. I don't worry about blowers, getting germs on my clothes or paper towels. I don't worry about restaurants as long as they look reasonably clean. One interesting note: A local lab tested various surfaces in restaurants and found that some of the highest concentrations of microbes were on the menus! John

Cool Mike! How did you waterproof it? John

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

Ok, thanks. I just wanted to make sure I'm on the right track for color cameras. I had the cameras mounted in environmental housings and had them pointing out of a window to test them. I thought that 2 layers of glass might be the problem. When I took the LTC0455 out of the housing there was no change (picture was still dark and really noisy). This particular camera is a Philips (pre Bosch). I talked to a guy that used to install them and he said there had been upgrades and improvements made to those cameras. I don't have a working Bosch 0455 but I do have both Bosch and Philips versions of the LTC0355. When I compare the 0355s, the Philips is considerably worse than the Bosch in low light situations. Maybe my 0455 is just an earlier version that is less sensitive. I took the LTC0495 out of it's housing and tested it with Sensup off. Now it looks real similar to the pictures I see posted on the forum Maybe 1 bad camera and 1 bad housing? John

I just got a Bosch LTC0495 with the Sens-up long shutter settings (x2-x10). I've just started playing with this camera and wonder what settings everyone uses. I'm really only interested in detecting people in the darker areas in my yard. I'm getting a lot of hazy blurry images on moving objects with the setting at X4 or above. Is this feature even worth messing with? John

Hi Mike, Sorry, I should have been a little clearer with my question. I am asking about the sensitivity in the color mode (forced-color only). The LTC0495 works really well in the monochrome mode. The Bosch cameras are the only modern cameras that I have so I don't have anything to compare them to except for the pictures that I see posted here on the forum. I am just wondering how they rate in the color mode in low light. Some of the pictures Rory and others have posted look great and they are from cameras that are less expensive. Since I'm on a limited budget I'm just trying to do the best I can with the money that I have available (all my Bosch cameras are used from commercial upgrades). Just looking for feedback from the people on here that have experience with Bosch vs some of the newer lower priced cameras. Sorry if I wasn't clear on that. John

I currently have a Pentax 3-8mm F1.0 lens (not IR corrected). It's the only F1.0 lens that I have. The current AGC settings are: ALC Level 0 MAXGAIN 20 ALC Speed Medium Are you using yours in the color mode with the 13W floodlight? I think I might need more light. I've only tried a couple of old color cameras and I still am learning about the lighting and sensitivity. Thanks, I will try what you suggested. Using a scope will be interesting. That's what I was wondering. Looks like it does wonders on still objects, but moving objects look blurry and noisy. It sure makes the sensitivity look great until something moves. When I look at some of the images that everyone posts the color images look great and it doesn't seem like there is a lot of light available. I have a street light nearby (maybe 60 feet) and my images look dark and noisy. Are the LTC0455 and LTC0495 lower in sensitivity than the newer (cheaper) cameras or am I expecting too much? Thanks for your patience! John

I just got a Philips/Bosch LTC0455 and it's dead. Does anyone know how to open these? So far I have gotten the black trim piece off of the front and side along with the little slide door. I've also removed the two little screws on the front near the focus adjust ring. That is all that I can see that holds this thing together but there is still something that won't let it come apart. Anyone ever taken one apart?

The slide covers are a good idea if you want to mount the camera in something with an opening to the outside and don't need to cut the glass. You just solved another of my problems

Got it! 2 screws under the label on top towards the back of the camera. 1 shorted capacitor on the 24Vac input filter. Power supply board is working again I think, now I have to see if the camera works. Thanks! John

Hi Dave, Yes, I don't think heaters are that necessary here in the south. The cameras that I have are box cameras, so they have to be enclosed in housings for outdoor use. Outdoor bullets would be a lot easier but they are outside of my current budget. All my cameras are older used cameras that came from commercial upgrades.

Hi I just bought a used Philips environmental housing. I estimate the thing to be 7-10 years old. I can't find a model number or picture, but it is tubular, about 14-15 inches long, about 3.25 inches in diameter,with plastic end pieces and a round front window. It opens by unscrewing two captive screws through the back plastic end cap and sliding the top section forward and off the mount/camera sled. There is no model number on it but it does have the Philips name on the side. 1. When I connect this thing both the fan and heater come on, even at 75 degrees F. I checked the internal wiring and it looks like the fan is powered all the time with no thermostat (?). Also the heater comes on and gets really hot even at 75 degrees room temperature. There is what appears to be a thermal switch for the heater which is mounted on the bottom of the sled with thermal compound. Does anyone here know if this is a special model set up for cold temperatures or is this standard for this type of enclosure? Any thoughts on the temperature where the heater should shut off? The camera in this enclosure had failed and I'm not sure if it was due to overtemp from this heater. I have an Ultrak enclosure with separate thermostats for fan and heater and so far it works well in this climate (Florida). 2. The front window in this thing is loose and I can't find any clips that held it. Are these windows just glued in? Thanks, John

Thanks Mike, That picture gives me a clue. Looks like there may be a couple more screws in the back part of the cover, maybe under the label. I am on a very limited budget right now (10-15 dollars per camera) so I would like to save this one if I can. Thanks, John P.S. Do I see vectorboard and standoffs in that picture?

Ok, thanks. It looked like the window was simply glued in. Our climate here does not get below 45 degrees F that often during the winter. We may have two or three days that get down to freezing for an hour or two. I really don't worry about cold, the problem here is humidity. I found that the heat from the camera will keep the front window from fogging on the Ultrak so I guess I'll try disconnecting the heater and fan on the Philips enclosure and see what happens. Thanks for the suggestion. I'll have to wait and see what happens when summer comes. I believe that I found information on the Philips enclosure, it's their model LTC9483. The scary thing is that they list the internal temp range as -4 to 131 F (-20 to 55 C). The 131 F is above the maximum operational temp for the camera that was in it. I'm sure that other enclosures also can get pretty hot inside but I'd never realized how hot that could be. John

After reading all of this I decided to try a little experiment. I have an LTC0355 (monochrome) and an LTC0455 (color). From the Bosch data sheets: The LTC0355 shows a sensitivity of 0.09 lux at 50 IRE. The LTC0455 shows a sensitivity of 0.26 lux at 50 IRE in the BW mode. Both cameras are rated under the same lighting conditions with the same lens by Bosch as far as I can tell. This is not a carefully controlled experiment but it is a practical comparison of the cameras in actual use. I set the cameras side by side aimed at a wall inside my house (medium gray color). The lenses are F1.4 Computar, 3.5mm, manual iris (fully open), focused on the wall. The only light source was a little nightlight on an adjacent wall about 8 feet away from the wall that the cameras were aimed at. (the light was behind the cameras). On the first test I used one of those little 0.8w LED nightlights (blue-white light, probably little significant IR). The results surprised me. Both cameras showed a noisy,dark image. The LTC0355 was a little brighter, had a little more contrast, and less noise. But none of these was a lot better. It seems that the combination of the 3 made the LTC0355 better. The edges of objects on the LTC0355 seemed a little sharper because there was less "speckling" on the edges. The contrast was easier to see because there were fewer speckles that hid the true shades of the objects on the wall. But I had expected a larger difference based on the specifications. I think both of these cameras would need additional lighting to be useful in this situation. On the second test I changed the nightlight to an older 4W incandescent type (should have reasonable IR output). This light was visibly brighter than the LED light. The results were very different. The LTC0455 now gave an image that was a little better than the previous LTC0355 image (expected because the light was brighter). The LTC0355 now produced an image that was dramatically better! It looked like I had used a much brighter light. I think the IR must be the reason. Now I can really see the value of IR sensitive cameras, but I think there should be a specification for IR sensitivity also. You really wouldn't know what a difference there is in these 2 cameras without trying this yourself. The specifications based on visible light really didn't help much. To all the experienced CCTV people on here please forgive me for making you read through something you've probably seen a thousand times before!

Hi, I have been tinkering with security cameras for my home for a few months now and have tried the KT&C KPC-S190SWX. The camera is only Black and White but it seems to do pretty well at night in the darker areas around my house (outdoors). The price also seems very good ($45-50 each). I am getting ready to order more cameras but I wanted to check and see how everyone feels about this camera and if there is anything better in this price range. Oh, I should mention that I want to install these as hidden cameras outdoors. Thanks