Lens quality

[Ted 0]

Far too often camera specs are focused on pixels and dynamic range. I rarely read how out of focus a lens is at the edge of an image at wide angle. The advantage of using a 5 mpix-camera at 90° view in a store is lost when using a cheap mediocre lens that blurs 30% of the image.

 

What brands of lenses do you prefer when it comes to image quality? Some manufacturers may be better at zoom lenses but worse on fixed or viceversa. Opinons?

[Baylab 0]

Wide angle lens with larger aperture( which is essential for the CMOS based 5MP camera) is the most challenging job in optical design. So don't expect razor sharp image from an " affordable " 5mega pixel lens.

 

I have to say, in a high resolution imaging system, the pixel is the cheapest component. A 5 mega pixel 1/2.5" CMOS imager just cost 2-3 bucks, if you but them with larger volume.

 

lens is another story, you can't just manufacture it by simply copying/printing ( like the technology used for image sensor). for any lens with decent image quality, people have to machine/ground the element one by one, and assemble them to the barrel one by one (normally just by hand).

 

if you have bought the lenses, what you can do is just try to reduce the aperture when the illumination is good enough to do so. However, if your lens is a manual one, it will be a dilemma: smaller aperture in day time will produce better image in bright environment, but the image will be unacceptable in low light. fully open aperture will improve the performance of camera in low light, and you will have to accept the soft edge and red/blue fringe in the image.

 

So, my suggestion is: try to get camera/lens system which can be programmed to use different aperture in different illumination.

[Ted 0]

There are no cheap good lenses. Its a pity that competition only results in extravagant specs of megapixels and fancy abbreviations and very little about sharpness and colors.

 

To have a good image in an indoor environment without exceptionally good lighting conditions you have to open up quite a bit. At the same time you have to keep it small enough to get a good focus depth to use the mpixels.

 

Are there any other manufacturers that like Avigilon, use 'real' lenses?

[Soundy 1]

This lens will give you excellent quality at wide angle:

 

 

Lists at a mere CDN$1040

 

Of course, you need one of these to mount it on:

 

[Ted 0]

Yes Avigilon does the job... In some applications they are perfect, in the average supermarket - the HD Pro may be a little expensive...

 

Anyone have any experience with Kowa?

[Baylab 0]

Broadcasting HD lens is not " a little expensive". some of them ( especially the wide angle one) could cost more than a BMW car.

 

The Kowa's "5mega pixel " lens should be good enough for the 5Mega pixel IP camera, actually, it is an overkill ( since most of lens in this category be able to cover an imaging circle of 11mm, the diagonal dimension of a common 5Mega pxiel cmos sensor is only 7.2mm, more than half of the area is wasted). they are quite expensive, the unit cost should be more than 900USD. maybe you can try their lower rank "mega pixel" lens.

[Ted 0]

Avigilon HD Pro cameras use Canon EF lenses so I guess I would get a few for the price of a BMW

 

What I really want is a lens which is a click above the average lens supplied by the manufacturer. For those average daily settings in stores etc to provide a bit better images, i.e. images with focus at the same distance over the whole image.

 

IQeye box cameras come with Kowa lenses but I suspect that the price is a too important factor and that Kowa (or any other manufacturer) may have lenses that are a notch higher in quality but not unrealistically expensive.

[Baylab 0]

Avigilon HD Pro cameras use Canon EF lenses so I guess I would get a few for the price of a BMW

 

What I really want is a lens which is a click above the average lens supplied by the manufacturer. For those average daily settings in stores etc to provide a bit better images, i.e. images with focus at the same distance over the whole image.

 

IQeye box cameras come with Kowa lenses but I suspect that the price is a too important factor and that Kowa (or any other manufacturer) may have lenses that are a notch higher in quality but not unrealistically expensive.

 

Just check what Motorbix did.

 

It seems Motorbix has abandoned ( actually they may never used) the C/CS mount lens, they choose to used some (maybe customized) M12 lens.

 

For the lens with same image quality, the C/CS mount version is definitely more expensive then the M12 version. because there are focus and iris adjusting mechanism integrated inside the C/CS mount lens. for a manual lenses, such mechanism will be used for only several minutes during their whole life span.

[Ted 0]

I'm borrowing my own thread here.

 

I need an (actually 20 pcs) 8-48 mm lens with f/1.0 (5-50mm will do as well).

 

Anyone know of any?

 

Edit: Never mind, found one, 1/2" Goyo Optical

[shropna 0]

This lens will give you excellent quality at wide angle:

 

 

Lists at a mere CDN$1040

 

Of course, you need one of these to mount it on:

 

 

Think about difference between Photo lenses and CCTV lenses. Difference is just in CCD or CMOS imager size

Avigilon uses large size sensors with large pixels, so, lens optical resolution less sense...

Edited August 12, 2010 by Guest

[shropna 0]

the image.

 

So, my suggestion is: try to get camera/lens system which can be programmed to use different aperture in different illumination.

 

What about diffraction effects on lens with "smaller" aperture?

Just one of examples:

http://www.conent.com/ConAdv/Encyclopaedia/Photography/CNQ_CAPhotography001.asp

This is not CCTV site, but physic is the same...

It looks, if you choose lens with smaller aperture, you will have more deep focus. But....

When you chose smaller aperture, you will have less optical resolution at "ideal" focus distance.

Edited August 12, 2010 by Guest

[shropna 0]

And, simple picture about lenses aperture and imager pixel size:

[Soundy 1]

So, my suggestion is: try to get camera/lens system which can be programmed to use different aperture in different illumination.

These are common - just look for "auto-iris". Doesn't really use "programming" as such - as the brightness changes, the camera (in a DC-iris setup; or the lens itself in a video-iris design) simply varies the voltage to the iris drive motor. Just requires a simple linear circuit, really.

 

What about diffraction effects on lens with "smaller" aperture?

Just one of examples:

http://www.conent.com/ConAdv/Encyclopaedia/Photography/CNQ_CAPhotography001.asp

This is not CCTV site, but physic is the same...

It looks, if you choose lens with smaller aperture, you will have more deep focus. But....

When you chose smaller aperture, you will have less optical resolution at "ideal" focus distance.

 

The variations don't really become as noticeable at most CCTV resolutions... the small pixel pitch becomes a larger factor than the lens aperture.

 

Plus, in my experience, you're usually going to be using a wider aperture anyway, as more light means less AGC and faster shutter speeds, both of which are big factors in CCTV image "usability"... plus with the super-small sensors and resulting short focal lengths - both of which also affect DOF - you end up with pretty usable total DOF even at f/1.

[shropna 0]

The variations don't really become as noticeable at most CCTV resolutions... the small pixel pitch becomes a larger factor than the lens aperture.

 

Plus, in my experience, you're usually going to be using a wider aperture anyway, as more light means less AGC and faster shutter speeds, both of which are big factors in CCTV image "usability"... plus with the super-small sensors and resulting short focal lengths - both of which also affect DOF - you end up with pretty usable total DOF even at f/1.

Of course, small pixel pitch is the larger factor, than lens aperture, but this is very close really

Just show me more megapixel cameras with large pixels, except "exotic" like Avigilon, Lumenera....

Also, lens manufacturers do "auto-iris" lenses with neutral light filters to reduce aperture instead of just mechanical aperture....

[thewireguys 3]

Fujinon has some nice MP telephoto lens now too 8-80mm 1/2 and 1/3 inch

[bantham1 0]

How about a high quality aftermarket lens for a cnb vbm-24vf? Does anybody make one that will be a direct fit with faster and higher quality glass?

[jxk716 0]

How about a high quality aftermarket lens for a cnb vbm-24vf? Does anybody make one that will be a direct fit with faster and higher quality glass?

 

I needed a wider lens for this camera and was told, by CNB, there are no other removable lenses. My guess is they have a proprietary lens on it but this is just a guess with my limited experience.

[Soundy 1]

It should be a standard M12 mount... although I don't know if you'll find a lens much faster than the stock (the aperture is unlisted, but you'll always be somewhat limited by the small mount). The included 2.8-10.5 is pretty good quality compared to some I've seen. I don't think there's really as much of a market for high-end M12 lenses compared to high-end C/CS lenses, so selection will probably be limited.

[bpzle 0]

I've noticed the lens that comes with the VBM-24vf is identical to that of Wren and some my favorite off brand Korean cams. Not sure of the specs or who actually makes them... but it appears to be pretty common make/model for domes.

[rory 0]

could try KT&C, but cant say if they are any better then whats on it now or if they would even fit, as they are both Korean they may even be from the same manufacturer:

http://www.ktnc.co.kr/english/viewtopic.php?t=466