CameraGimp

To address your first question Post subject: WDR / PIXIM are these 2 technologies the same? if not what are pros and cons? The answer is no they are not. WDR is a function or feature, Wide Dynamic Range. Pixim is a manufacturer like Sony or Panasonic. Pixim positioned themselves as WDR manufacturer but there are lots of other companies making WDR cameras. Panasonic being the most notable, they were the very first to bring out WDR and are on gen3 WDR now and quite a few people swear by them, but they aren't cheap. Pixim were the new boys and created quite a splash but they are not to everyones taste. To correct a poster up the thread Pixim are not a CCD manufacturer, they are a CMOS manufacturer.

There could be two issues effecting you. 1. IR can focus at a different point. If you remember light going through a prism from your school days you should know that white light gets split into a rainbow red to blue. This is exactly what happens in a camera lens and it is called chromatic abberation. Fortunately a camera lens is made up of a number of pieces of glass and the smart lens designers make these bits so all the colours end up back together or at least the good ones do. The principal is exactly the same for IR. The light going through the prism goes blue to red and the IR is just beyond the red. Only thing is we can't see it. The problem is because we can't see it many lenses are designed to bring it back to focus. Why bother if you can't see it. That is why you should use IR corrected lenses (not IR coated!) 2. This is probably the more important one. If your lens is auto iris your depth of field will reduce as the light goes down and the iris opens. As a result something that was in focus can go out of focus. To avoid this you have to as recommended adjust your back focus with the iris fully open. This is worse case. Open the iris by focusing at night, using a strong filter (welding glass) or if you now what you are doing setting the camera to a fast shutter speed.

I did exactly that with a Grandeye camera (put a none fisheye lens on it). To do it right you need a mega pixel lens or you'll not get the full resolution. You will also need to be able to output the whole image, I'm not sure if Ipix supports that. If you get it working let me know. I was thinking of offering the 2MP camera as front of house in banks. Put a few of those in and record the full resolution and you'd be able to get some good close ups after the event but it never happened.

They do analogue and IP cameras and a recorder. I was involved when they only had the analogue camera in production and the DVR in pre-production so I can't really comment on the IP camera or the DVR in detail. The analogue camera is exactly that, an analogue (composite) video out camera although the electronics made it extremely digital inside. The camera was designed so that you could fit it anywhere you had a standard fixed camera and it would give you 360 vision about that point. The camera has two video outputs each addressable via RS485 (Pelco D and other protocols). The camera supported 8 virtual cameras. You PTZ anywhere in the 360 scene and it looks like you are controlling a real PTZ (albeit without a massive zoom). You could have two operators controlling individual Vcams at the same time on the two video outputs. Or you could switch the output to quad and position four vcams to look at four different views. It was very configurable but the resolution was just a touch too low in my opinion. That was with a 2MP imager.

I think those mega pixel numbers are inaccurate. The camera is definitely the Grandeye Halocam (aka Vista Halocam). It looks identical and uses the same marketing literature. Seeing as the manufacturer is only quoting 5MP I do not know how an OEM can claim 38MP. Any way it just isn't practical. To get 1 lux sensitivity the imager would have to be the size of a playing card and you wouldn't be able to clock that many pixels out and get a frame rate needed for video.

38M pixels?? Not in the Grandeye camera unless I've been frozen for 10 years. It just isn't possible with todays technology. They were about 2MP when I saw them and 5MP today which will make somethings better and somethings worse. If you are planning on going to Ifsec go over and have a look. It is fun.

Seen the picture now. My Internet must be going slow. It looks like a conventional box camera with ptz with an insert that makes it look like there are four cameras. If I am right I bet the everything moved together. If you look carefully you can see a cross in the dome. This is going to be hard to describe! The camera is probably looking to the left, 9 o'clock as we look at the image and it can be tilted down to 6 (looking straight down). It will also be able to rotate 360. Basically it is a conventional camera on a ptz inside a large dome housing. The lens pokes through a plastic insert. The insert has a channel so that it can tilt from horizontal to vertical. As the camera turns the whole insert turns, as the lens pokes through the insert and pushes it round. There are dummy lenses moulded into the insert at 45 degrees to the camera. I am pretty sure Photoscan used them. I managed to lose my spleen whilst repairing one once. My memory of the day is not the best as I'm sure you can imagine but that is what it looks like, and Photoscan did a lot of city centres in the UK so it seems to fit.

I can't see a link. Am I going mad? Rebco - I've worked with the guys who designed that 360 fisheye camera. That was a cool product, the design house is in the UK, called Grandeye. I can't see that working outdoor though. It was good but it had its limits.

In reply to the question "why don't we use SVHS output then". Two things it is only certified upto something like 2 metres (so not very useful). Secondly and I'm just being a bit picky here but SVHS is a video recording tape or standard, the output on a camera is S-Video. S for separate video rather than composite video. S-Video uses two pairs of wires one with the lumninace the other the colour information. It's cleaner and so achieves better resolution.

You might be able to modulate and then demodulate at the other end, that should allow you to put multiple signals on one cable (like TV) but if you are trying to save money by running less cable I think you would be better off looking at using twisted pair baluns (google NVT). This still only allows one video per pair of wires.

I've not seen four PTZ cameras in one housing either. I have seen one ptz camera in a large dome style housing with an insert that tries to look like three dummy lenses, each at 90 degrees to the real camera. When the one camera turns the other three rotate. I think Photo Scan used them. Could this be what you are saw? How big were the cameras and lenses and how big was the housing?

Wiring a CCTV camera to a television is easy as long as the television has a composite video input. The only thing that may cause you a problem is sound. Most CCTV cameras do not have microphones so you may have to set something else up for that. There are cameras that capture sound but the ones I've come across have low end microphones and so may not be very good for long term listening.

From a product design view I'm not sure getting bang for buck is as important as performance when choosing WDR chipsets. WDR cameras can demand a premium over standard colour cameras and I bet the extra cost more than covers the chipset overhead. WDR cameras should make manufacturers more margin. So it would seem sensible to try and make one that is good enough to steal competitors sales. I would go for the best chipset available and take a hit on the margin if necessary because it won't be that big a hit and you want to get a big share of a high margin sector. If your camera is good and priced right it should sell. If your camera under performs it won't sell as many and then squeezing a few dollars from the chipset won't seem so smart. Tell you what would be useful. Could you post the various chipset costs so we can rate how each performs against the cost?

There is a bit of confusion on day/night cameras. As Rory points out most of it is down to manufacturers being misleading with there descriptions and specification. So here my pennies worth. Going monochrome does nothing to improve sensitivity. Removing the IR cut filter is where the sensitivity gains come from. Once you take the filter out the camera can "see" IR light so it becomes more sensitive. Even if you don't have IR lamps, there will be IR bouncing around. It is just that we turn a camera monochrome at the same time as we remove the IR filter so some assume the sensitivity increase is a result of the cameras going mono. It isn't. We turn a camera mono because colours go wrong when we pass IR and you'd all return your cameras as faulty if we didn't. There are three types of day/night that I am aware of: True day/nights. These are one with a mechanism to move the IR cut filter. As Rory says you can usually hear the filter being moved. These are the best type, true colour during the day, IR sensitive at night. The only downside is the camera has a moving part, this can be a concern for reliability. Colour cameras with a fixed IR cut filter that go monochrome. These are no better than turning the colour down on your monitor and are just a con in my opinion. Colour cameras with no IR cut filter that go monochrome. These have the same low light performance as the moving filter cameras but they will have poor colour reproduction during the day as they are IR sensitive all the time. These cameras actually cost more than a colour equivalent but cost less to make! Same camera minus the filter. Marketing! A trick to watch out for is if a manufacturer limits AGC when in colour and increases it when they switch to mono. This increase in gain boosts the video level and you think the camera has become more sensitive. It hasn't the camera was just under performing in colour! I have seen this on colour cameras with IR cut filters as a way to make you think you are getting something for your money.

The Vista cameras should have a power rating on the label. I assume they are low voltage in which case the label should give you the voltage range (12VDC or 24VAC or both) and the wattage.

Oh yes. I guess there are now a lot of what I would call barrel mount lenses out there. Ones that screw onto a board mount rather than to the camera chassis. I bet a high percentage of cameras built nowadays are basically board cameras in a box and use barrel mounts rather than the lenses I was used to.

In CCTV there are two lens mount types, C and CS. They are the same thread so you can screw a C mount lens onto a CS mount camera and vice versa but you may not be able to focus it. C and CS are nothing to do with the thread but refer to the back focus distance, the distance between the rear flange of the lens and the CCD. I can't remember the distances but they differ by about 5mm, with CS being the shorter distance. Some cameras can adjust the position of the CCD to cope with both C and CS lenses. Some can't. If they can't the camera is usually CS mount only, as you can still use a C mount lens on a CS mount camera if you fit a 5mm spacer between the camera and the lens. I think I got that the right way round. Anyway my point is, there are two types and you need to check which your camera takes. .

I think it is worth clarifying that a camera cannot be PAL and NTSC at the same time! The datasheet of the camera on ebay is for two models the PAL one and the NTSC one. Some cameras can be switched between PAL and NTSC (Pixim!) but they are not PAL and NTSC at the same time.

I think you are looking in the wrong area. It isn't the CCD but the DSP that is the key to 520TVL. Ignoring progressive scan and other such imagers, Interline (ILT) CCD's resolutions haven't changed in ages. You get two resolutions medium (or standard) and high and it doesn't change if the CCD is 1/4", 1/3" or 1/2". The same CCD that was 480TVL three years ago can now be 520TVL the increase comes from the DSP not the CCD. So the HQ1 you have seen refers to the DSP not the CCD. When I was a lad there was the 2163 aka SS1, open up any sony based camera that is a few years old and chances are it will say 2163BR on one of the chips. This was the first DSP Sony released and it is probably still in use today. Then came the SS11, I think this was a lower cost one, maybe only MR, can't remember. SS-HQ1 will be the 520 one. As well as changing the DSP the filter in front of the CCD will be different. A colour CCD has the same number of pixels as a black and white CCD. This begs the question why are the resolutions different. The resolution has to be stepped down on a colour or you will get colour fringing , the posh name is Moires, the simple name is barbers pole effect. The filter fitted in front of a colour CCD doesn't just cut out IR light. It also cuts out high frequencies. This bit is called Optical Low Pass Filter (OLPF). So the filter is an IR cut and OLP filter and this actually limits the resolution of a camera as well.

Top comments from Rory, I say beware manufacturers specs. ..above DVD quality.. Mmm what does that mean? It means nothing to me. The Sony ExViewTM chipset produces an astounding 600 lines of resolution... and so will any camera with the same CCD or any B&W HR CCD. With an industry leading low 0.0003 Lux..... That is is alot of nothing....with what lens and what light source do they make these claims? I might as well say it is my massive white arse reflecting the sun that makes it perform so well. Buyer beware

It is quite late with me and I've just logged in between the pub and bed so I may be off with this one...but Are you looking for a procedure on how to set back focus on a camera fitted with a zoom lens? If so try this Set the lens focus to infinity and fully open the iris by covering the lens with a suitable neutral density (ND) filter. Zoom out to the widest field of vision and view a distant object. Adjust the back focus until the object is in focus. Next, zoom fully in and adjust the lenses focus until the object is again focused. Repeat these steps until the full zoom range may be viewed with the minimum loss of focus. The last sentence seems a bit vague but then I'm slightly drunk!

Have you seen Metal Mickey? It is a PTZ with 360 rotate and 320 degree tilt. About the same size as a dome. Made by Forward Vision. This should be ok looking up.

Hi there, I have attached a guide to CCTV cameras that I wrote awhile back. It was written as a sales aid for a camera brand so the features explained reference their cameras however the functions are the same on all manufacturers so don't be put off. It may help to explain what all those switches do. Pat. Mmm. My attachment hasn't attached. I'll host it at www.darkdata.co.uk/camera_lenses.pdf for a couple of days.

We need some more information to be able to give useful advice. Can you expand on what you mean by poor clarity? To troubleshoot you should try and isolate likely problem areas. So if you think it is the transmission you should try and take it out of the equation with a test monitor. Once you've ruled out one you move to the next.

Hi, You say you have set the shutter speed to 1/160s. In my mind that sounds wrong. If you are using a manual iris lens you shouldn't have a fixed shutter speed if you want the camera to adjust for bright light, it will also reduce your low light perfomance. You need to let the camera control the shutter speed across it's full range ie 1/50 to 1/100,000s (usually) something I would call electronic iris in the UK. If things don't go well do you have a manual you could point me to? Pat.