Low Light Camera Test Comparison

[cctv_down_under 0]

The following is a camera test that was done in order to test the Baxall Full Body Cameras - we had been using their dome cameras (Well actually some domes that they chose to OEM and they were excellent) and thought we would try to compare their full body range!

 

The test is not a perfect lab test and althought the area in testing had changed slightly within the two days of doing the test (bloody phone calls) I am confident that the lighting levels would not have differed enough to warrant any favourable or unfavourable outcome.

 

I wanted to see the results "out of the box" hence gain was left on ect and therefore noise has resulted in most of the images, the only change made was to switch the XF Daynighter into a low light mode (the out of the box settings can also be seen in another image)

 

Anyhow I hope this helps...special thanks to Rory becuase I could not gett he site to allow me to upload all the images ...Rory did some for me.

Edited October 6, 2006 by Guest

[cctv_down_under 0]

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[VST_Man 1]

one problem with most "extreme" low light camera's is that they produce a ghosting effect not displayed in a object standing motionless. Yes, you can get a decent low light pic but will the pic display details? Ghosting wipes details dispite the nice low light.

 

Bottom line; ALWAYS use lighting if you can. Motion, dusk to dawn, ect. I even advise my clients to have a electrician wire a couple in store lights to remain "on" 24/7 so that the camera's have a better picture than depending on low light images. IR is also a great tool in enhancing the pic but the camera/lense has to be IR sensitive/corrected. The best I've seen to date are the new WDR's..combined with IR they produce a very clean pic at night..............no ghosting, no pixeling, just clean.

 

I've seen several crimes on video from my installed systems and there are two distinct types of thieves. One does not care if you video them and the other tries to "mask" it. They all get in and out in under in minute. So for one minute you have to be perfect. The smallest detail will help put the puzzle together. ie. Store was broke into and there was one young man who wore unique clothing during the robbery and also early that week when he was in the store shoping. They were in and out in under 45 seconds but several frames showed his clothing in detail. Reviewed the historic video and there he was with his partners...filling out credit apps! Busted!

 

My point, the lighting was critical in identifying details............one piece of the puzzle fit just right.

 

Sorry if I got off track. Just wanted all to know that low light camera's have some issues.....

[rory 0]

Actually for IR you dont need a DN / IR Corrected lens to get a great image under IR in pitch dark .. and the camera matters but doesnt have to be a WDR just for that ... the thing is the IR Corrected lenses just add a bonus to not having to worry about focus shift in low light ... with a normal lens basically if you focus it under IR it will be as good in the day with Sunlight as it is under IR (depends on the IR), but in low light is where it suffers, such as cloudy days or early evening/sunrise .. Ive used Aspherical lenses in the past with great success ... also, there is less chance of Focus shift with narrower FOVs such as 10mm+. Course the WDR can fix other issues like glare from car lights, etc.

 

Basically the IR bulb you use and its installation, is what really matters when dealing with IR . . could have the best camera in the world but if the IR Bulb/LEDs are not the correct ones for the location, or not installed properly, then the image still wont be great. Ofcourse the camera matters also, but its only a part of the equation.

 

Either way IR is a head ache, much easier just to add normal lighting.

[cctv_down_under 0]

I am not tottaly sure but I think some of that info is wrong rory, IR corrected lenses do help with the focal shift, especially if using an IR cut filter, we all know that the iris changes in low light and this obviously effects field of view, but if using a IR cut filter, then the distance between the sensor and lens has changed as the device is moved away, some cameras use what is known as a Dummy IR filter that slides over where the filter originally was for this reason.

 

I was under the understanding though that some non ir corrected lenses will block the amount of IR light as they have IR treated glass, so I am not sure that it would be accurate to say that the only advantage is focuss shift.

 

I am not a big fan of IR unless you pay decent money and have it seperate to the camera itself IE UF500 etc, I have hardly ever needed to use IR except in conditions where I can not see my hand in front of my face in complete darkness, I prefer to step up to a half inch D/N camera instead as IR is hardly ever needed.

 

As for the interlace caused by delaying the frames, thsi can be managed by good cameras, so you can set it to what you want...the biggest problem people have is they think they should just whack a camera on low light mode and be done with it...which is very wrong to do..

 

How can a manufactorer know how low your lighting is...so they set there low light mode to a ridiculas "worse case scenario level", most of the low light cameras I have seen on site have been set way to low, causing frame interlacing and more importantly massive noise due to gain.

 

The reason I like the Bosch is becasue you can program it up the coax, meaning you can isntall it and sit in a room and adjust Gain, Level, Frame Interlace, Dynamic Range, Amplification BLC Levels etc all from the laptop, this is great because fractional changes can make such a difference and being able to adjust it a bit at a time with each setting really helps..

 

If you look at the Bosch Day Night cam with out of the box settings you can see that by defualt it is set so low that it is trying to stay in colour but it is causing massive amounts of noise because of the gain increase... but the other image where I have adjusted the low light settings allows it to switch to B/W and takes a lot of the gain out of the picture (I could have done a lot more).

 

The other reason I like it is because you can do the back focus without having to adjust anything, you just switch it into back focus mode and although it looks like nothing has changed it actually has the same effect as using a Nuetral Density Filter and making the Iris adjustments and there are no screws, in order to dot eh Baxall I had to adjust a screw hold a ND filter and change the DC Level at the same time as focussing.

 

~ I hope this helps

[rory 0]

yeah the first paragraph i agreed with .. either way they need a true day night camera .. the sanyos worked out good on the extreme job i did .. but the ge had more features .. both were the same under the UF 500 though ..

 

Also it may help produce some more IR to the camera ive never tested, though with the aspherical lenses and the Extreme IR's it was like daylight with the ones i used, with some focus shift in low light but not much on the 12mm ..in fact Extreme will tell you there is barely any focus shift over 4.3mm, and you can also focus the lens off by about 10% to help fix some of it .. probably makes a bigger difference on the cheaper cameras and IR .. i never really messed much with those .. like you said, if they go IR they should use the right gear anyway ...

[cctv_down_under 0]

Aspherical Lenses are a completely different kettel of fish, spherical abhoration is commonly found on most non aspherical lenses, this condition is caused by using such an easy way to mechanically grind the lens (circular machine polishing), by polishing and grinding the lens in a spherical manner you do not end up with such a precise focal point.

 

The chromatic abberations (colour decomposition of white light) can also effect the quality of recieved light but as mentioned above one of the major factors is actually the profile or shape of the lens.

 

The optical axis is effected largly by shape of the lens, most lenses that are not aspherical have a standard curvature that is very easy to machine, however a aspherical lens has more of a bell shape to it, kind of like a wave with a peak in the middle, these are harder to machine but the effect is that light is better distributed onto the sensor in a more concise and effective manner, meaning (well not exactly) that light is not wasted and falls more evenly on the sensor allowing the sensor to pick up more light and therefore perform better in low light.

 

Some of the advantages of having an aspherical lens are that in some cases you can achieve shorter minimum object distances, wider angles of view and fewer optical elements (because there are less abborations to correct).

 

There are some moulded aspherical lenses in the mrket, these avoid the process of grinding and therefore are much cheaper but this does not guarantee the same glass quality which is a completely different issue.

 

Most people only consider Fstop, size and brand when considering a lens, but IMHO the most important consideration is Lack of abboration, the T.FACTOR (Transmission factor- reliant on the quality of the actual glass and how well it transmits light) and this is often overlooked.

 

The F stop is JUST a measurement and should NOT be the only factor that is considered.

 

~ I hope this helps

[cctv_down_under 0]

Anyone got any other cameras they want to send to me for testing

[CSG 0]

most probably look at the price, and the focal length, in that order

[Cooperman 0]

I am not tottaly sure but I think some of that info is wrong rory, IR corrected lenses do help with the focal shift, especially if using an IR cut filter, we all know that the iris changes in low light and this obviously effects field of view, but if using a IR cut filter, then the distance between the sensor and lens has changed as the device is moved away, some cameras use what is known as a Dummy IR filter that slides over where the filter originally was for this reason.

 

I was under the understanding though that some non ir corrected lenses will block the amount of IR light as they have IR treated glass, so I am not sure that it would be accurate to say that the only advantage is focuss shift.

 

Hi cctv d u!

 

Just to clarify, IR corrected lenses are designed to focus near IR frequency light at approximately the same plane as visible light, so there is no need to make compensatory adjustments when using cameras under a broad spectrum of light frequencies.

 

If the camera is fitted with an IR "cut" filter, then little or no IR light will be reaching the imager.

 

'Field of view' is simply a product of focal length in relation to imager size. Adjusting the iris does not in itself have any effect on the 'field of view'.

 

Sorry to be picky, but I thought it best to be accurate for the benefit of others reading this.

[kensplace 0]

The iris just alters the light levels, and the depth of field (how much is in focus at once in the shot).

 

With the iris fully open, there is less depth of field, meaning you need to focus on the area you want, and other futher away areas may be out of focus.

As the depth of field is shallower with the iris open, its easier to see if the image is properly in focus, which is why when people back focus they open the iris fully, either manually or by using nuetral density filters of some sort.

 

Close the iris, and the depth of field is greater, meaning more is in focus, but as more is in focus, its harder to know if the image will be in focus when there is more light and the iris is open more.

[rex 0]

An IR corrected lenses have extended focusing ability from visible range (400-700nm) towards infrared spectrum of light (above 700nm); otherwise with IR illuminator picture will be out of focus.

[rikky 0]

Hi CCTV_donw under,

 

As I'm reading your paragraphs on the Bosch cam's, you mention on the backfocus that you can switch this on the camera without using a ND filter.

So far so good, as this feature is also available on other cameras.

 

Adding up to that you mention that there are even no screws. Does this mean you set the backfocus completely vie PC, without going out there at the camera?

[rory 0]

I think he means it has an auto back focus feature, alot of brand name cameras have this feature available now also.

[cctv_down_under 0]

That is correct, you push a button on the side of the camera and the picture will lok the same to you, but it is now in back focus mode, so you do a normal focus and adjust the ring without having to adjust Iris, Level or use a ND Filter, yes you can set that by PC but you do not have to, all the functions that are set by PC excepting controlling PTZ's and Upgrading the ROM can be done at the camera only if need be.

[mcs 0]

Do a test on the Samsung 740- and post back results,

 

Ill be testing one 740 and a 730 and 415 over the weekend and Ill post footage off the Geo when I get back from My course wed next week.

So stay tuned to this thread this time next week.

 

Subscribe (to this thread- NOTIFY ME WHEN A REPLY IS POSTED, tick below) to have an email reply so you dont miss out.

[videobruce 0]

Exactly, what is/are the model number(s) of this/these cameras??

[mcs 0]

SHC740

 

 

Ill post pics I got in late (Long drive from Brisbane)

 

cheers

[forecamsales 0]

focal length:3.5-9mm IR

format:1/3

board mount

aperture:F1.2

aspherical lens

this is a special lens with IR function

[photys 0]

Hey mcs.

You still got those Samsung samples?

Im about to buy a few different models to test.

[mcs 0]

I wouldnt go under the 415, its base range in my mind- the 310's and 313's are ok inside with no external light issues,

530tvl low light the works, about the same as the sid450 dome, I love this dome

 

 

the 730 is about the same yet lower light level

and the 740 is optimum 1/2" ccd, hi res 540 tvl and low light 0.0001 without checking the box (mono switching)

 

 

I know one guy using Bosch, all he goes on about is bosch this and that

yet he uses Samsungs 4020 domes, they rock- they are the best Vandal resitant dome around... (plus for the price)

[photys 0]

Thanks mcs.

Seems I was looking at the same models.

 

Ordering a 415, and the 450 + 4120 domes.

I dont need the WDR in the 4120 so I will grab a 4020 also.

 

Will price up the 700 series as those specs look great.

[mcs 0]

Trust me coupled with a geovision DVR you wont be disspointed, specially with live view card

 

THE dvr generally lets the cameras down

 

I use the 415 as my base camera, then the dome over tills and in low places where people can fiddle plus its cheaper then 415 and lense (same specs)

 

The 730 is good, but the 740 is the best for number plate recognition,

 

Let us know hey when you get them to test,

That way people can hear it from someone other then myself:)

 

 

SVIII coming soon,

 

 

I like Bosch, but theyre staff are arrogant edit : (management, I didnt want to point fingers) plus they are not interested in supporting the liddle guy whos battling his way to the top- ONE HATH A LONG MEMORY...

Edited August 27, 2007 by Guest

[cctv_down_under 0]

Damn, that means I used to be Arrogant LOL

[mcs 0]

NO " management "

 

Doesnt mean sales,

 

"removed" off topic

Not the right place to vent, Sorry people

Edited August 27, 2007 by Guest