13 replies to this topic

[tcm]

Hi fellow cctv fitters,


quick question or two or three i fitted a cctv system for a client using samsung domes b5368-p the picture is good and i like the dome itself but he recently had a incident an said the picture wasnt good enough for a conviction possability of the crook saying "nope thats not me"(this is not the police saying this its him so jurys open verdict as yet)

Question 1. Do you fellow installers rate these domes yes or no.
Question 2. If you dont what direction would you take i.e product must be a neat stle dome, Ip cams not a option.
Question 3. Does the dvr make a huge impact on the picture quality i.e it records in 24/7 cif not h.264

The reason i ask is because he wants an upgrade for more cams.

below hopefully is a snapshot of the cam in question. (I think the led lighting on the bar are playing havoc with the picture?)




Yours hopeully
Tcm

[Neutech]

Have installed 300 + of these and no issues

Used in various enviroments including Pubs and Clubs

Make sure you play about with the various settings in the menu as they can be adjusted

2Cif is as low as i go mostly D1 going to CIF and blowing it up to full screen is poor, whats the DVR being used?

There are a number of ways to setup cameras to make sure you have a quality image of the person concerned, i get a lot of work doing setup of systems from clients who have had someone else into do install and made a pigsear of it.

[tcm]

Hi Neutech,


Thanks for the repply the dvr is a apollo hd

[digitalwitness]

At first look, those cameras are rated at 600TVL but when recording at CIF you are only recording 264TVL of them (without taking compression settings into account). Without trying to complicate it too much, CIF is 1/4 the resolution of D1.

If the live image is acceptable then that points towards the record settings but as the apollo HD is upscaling the live view (especially if using the HDMI port), live may not be an accurate indication of what can be recorded.

[bm_99]

Not really sure about these dome but have used the samsung external body cams and they are really good (if not a bit expensive) but for the right customers worth it

For dome specifally internal ones, i've always said the Vista ones are hard to beat for the money you pay vs quality and warranty
But only use them in full d1 mode really

[tcm]

Hi guys,

Went to site today and looked at the site and my first suspision was correct lots of led mood lighting now being used and it is causing some issues with cams (arranged to go to site and set up at night with all the lights on so i can get them spot on.

Also now changed the recording to d1 highest quality this should improve the playback.

[emsgeorge]

Dont forget some of the apollo models only do 6fps in d1 res - so check the specs, and have a chat to your customer - some areas might need higher framerate - like the lobby area etc, and can get away with lower recorded res.

Ive also met one council who specify the actual framerate (a minimum) in their licencing conditions, although no quality level !

[Adi]

D1 all the time, never record half of what is available. Makes a big difference.

I use the apollo, it will give a good playback on D1.

Make sure the hard drive if big enough, dont mess about with half a G.

And as above, it will only record at 6fps, make sure client is happy with that.

Not used the cams so cant comment

[digitalwitness]

I'm afraid that its not quite that simple any more, D1 or HD1. There are so many different profiles for H.264 and ways of implementing it, as not to get too complicated, generally the Koreans have used Hardware compression where generally the Chinese have used DSP, both have their advantages/ disadvantages and limitations.

But to get to the chase in this regard, one main difference between the two methods of implementation is the sampling frequency of the compression, comparing similar level machines, the Koreans I have seen go over 6Mbps where the Chinese go to 2Mbps (can depend on the number of channels though as the 32Ch only goes to 1Mbps), this is at D1 best picture quality.

There are other factors to consider so I am not saying that there is 3 times the picture quality difference but where you may see the difference is when there is a large amount of movement or change in a picture, so the choice to use D1 or HD1 (which is more than acceptable to the human eye) will depend on the application and equipment used (including camera choice). Oh and watch out of interlace noise if using D1 with fast moving scenes.

[jameswilson]

Tony, what is the artnix at d1 on best. Am i right in think ing that is 6meg?

[digitalwitness]

Hi James, it is 6.3M and I believe this to be relatively standard amoungst the Koreans (or at least close to it), there are chinese versions that go up to that but those DVRs are significantly more expensive than the Korean machines and generally reserved for Hyrbids or NVRs (megapixel).

Its not the only factor when it comes to picture quality but could be a significant factor in certain situations, like at low light with CCD noise, all the power is spent saving the differences due to noise rather than the target required.

[jameswilson]

well from my tests i wouldnt want to drop below 6 meg as a max. Its not a problem in high light levels. 2 meg is probably enough. But if you get any noise in the image or high motion then it isnt.

[digitalwitness]

In my experience the two different applications are not directly comparable, i.e. 2M on a Korean DVR versus 2M on the Chinese when comparing overall picture quality, this is simply more about been able to handle changes between subsequent images.

The apollo have the option of VBR or CBR (Variable or Constant Bit Rate), Koreans general just use VBR and the 6M setting as the reference bit rate, reducing the quality on the Korean DVR will also reduce the Bit Rate. Its quite easy to see the effects on an apollo by setting the Bit rate low but keeping the picture quality the same. Compare two cameras will similar movement (high movement preferably) one on VBR and the other on CBR both at a low bit rate and the effect will be evident. CBR is handy though for network transmission.

[Adi]

digitalwitness, on 17 August 2011 - 09:03 AM, said:

I'm afraid that its not quite that simple any more, D1 or HD1. There are so many different profiles for H.264 and ways of implementing it, as not to get too complicated, generally the Koreans have used Hardware compression where generally the Chinese have used DSP, both have their advantages/ disadvantages and limitations.

But to get to the chase in this regard, one main difference between the two methods of implementation is the sampling frequency of the compression, comparing similar level machines, the Koreans I have seen go over 6Mbps where the Chinese go to 2Mbps (can depend on the number of channels though as the 32Ch only goes to 1Mbps), this is at D1 best picture quality.

There are other factors to consider so I am not saying that there is 3 times the picture quality difference but where you may see the difference is when there is a large amount of movement or change in a picture, so the choice to use D1 or HD1 (which is more than acceptable to the human eye) will depend on the application and equipment used (including camera choice). Oh and watch out of interlace noise if using D1 with fast moving scenes.

it is on an apollo, cif is ****.

agree with last comment