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jsimon

Cmos cameras

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I was trying to fight again this cheap products that Costco and PriceSmart sell, and the only way was selling too cmos cameras as an otion for the customer, Since that I sold like 300 units, every time I order from diferent distributor and quality between them are very different, some you need a lot of light, other evey thing you see apear to be green etc. How can I find which one is the best, I mean they all say that have 320 lines, the only diference that i found was the db, and I feel doesn't affect too much quality.

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Well, you guys need to understand that where we comes from, even $100 american dollars for a decent camera takes a month's salary from many people, so even the cheapest, crappies stuff is really the main choice we have.

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CMOS cameras are typically very cheap and although somewhat better than the old tubes cameras need alot more light than today's CCD chip cameras.

 

Last week I was introduced to a High-Definition camera. It produces more lines than any recorder on the market today can record. They actually had to throttle it back to 720 x 480 so that it can be recorded by capture cards with progressive scan. It's not cheap. Retail $695.00. They use CMOS. GO FIGURE.

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CMOS is a fairly new technology compared to everything else out there. The thing is that just like a CCD camera, it's all in the circuitry that is behind the sensor. The good thing about Cmos is the low power that it requires to operate, so that's why you see 9Volt cameras poping all over ebay.

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Not to take issue, but CMOS is OLD technology. The first chip cameras that replaced tube cameras were MOS. The first color cameras were CMOS. They're like some of my old ties. They've been around so long that they're new again.

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"CCDs have been the dominant solid-state imagers since the 1970s, primarily because CCDs gave far superior images with the fabrication technology available. CMOS image sensors required more uniformity and smaller features than silicon wafer foundries could deliver at the time. DALSA founder and CEO Dr. Savvas Chamberlain was a pioneer in developing both technologies in the 1960s, and his leadership helped bring CCD technology forward. Only recently has semiconductor fabrication advanced to the point that CMOS image sensors can be useful and cost-effective in some mid-performance imaging applications.

 

CCDs offer superior image performance (as measured in quantum efficiency and noise), and flexibility at the expense of system size. They continue to rule in the applications that demand the highest image quality, such as most industrial, scientific, and medical applications.

 

CMOS imagers offer more integration (more functions on the chip), lower power dissipation (at the chip level), and smaller system size at the expense of image quality and flexibility. They are well-suited to high-volume, space-constrained applications where image quality is not paramount, such as security cameras, PC peripherals, toys, fax machines, and some automotive applications.

 

Costs are similar at the chip level. Early CMOS proponents claimed CMOS imagers would be much cheaper because they could be produced on the same high-volume wafer processing lines as mainstream logic or memory chips. This has not been the case. The accommodations required for good imaging perfomance have limited CMOS imagers to specialized, lower-volume mixed-signal fabrication processes. CMOS imagers also require more silicon per pixel. CMOS cameras may require fewer components and less power, but they may also require post-processing circuits to compensate for the lower image quality.

 

The larger issue around pricing is sustainability. Since many CMOS start-ups pursue high-volume, commodity applications from a small base of business, they must price below costs to win business. For some, the risk will pay off and their volumes will provide enough margin for viability. But others will have to raise their prices, while still others will go out of business entirely. High-risk startups can be interesting to venture capitalists, but imager customers require long-term stability and support. "

 

from:

http://www.dalsa.com/markets/ccd_vs_cmos.asp

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Rory,

Wow. That was quite a response! The first color cameras I could get my hands on were CMOS but they were quickly replaced with the CCD's. I probably still have a CMOS or two left around from years ago. I'm going to have to dig them out and compare them with today's models.

 

I do have to take issue with the statement "... where image quality is not paramount, such as security cameras...". I think the public expects that we provide the very best image quality.

 

I hope you saw my post on the other forum. I hope I don't sound like a smart ass, but over 17 years, I've managed to screw up more than most people. I can tell you a lot of things that won't work.

Howard

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Yeah I hear you man, yeah I noticed that part on security cameras also, I think they may have had too many dealings with low end clients or Sams Club 17 years, now that is some experience ...

 

I used a Cmos camera sent to me by mistake (eclise) the other day, and it was soo crappy, i gave the distributor a piece of my mind, since the product i ordered said nothing about it being a Cmos camera, or I never would have ordered the POS .. plus it was supposed to be a 3.5" dome, and turned out to be 2.5" ... havent heard back from them since then! There is certainly a HUGE difference between CCD and Cmos. Though that said, I saw a digital camera by i think Mustak or something like that, was a mini mega pixel camera, and images werent bad, but then thats a still camera, and "still" cost alot more than a Cmos CCTV camera.

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That's after spending 20 years as an accountant. I had a BIG advantage when I got into distributing CCTV. I KNEW I DIDN'T KNOW. So, I asked a lot of questions.

 

Fortunately, there are formal training programs around now. 17 years ago, the only training was from guys trying to sell you something. They taught you what they wanted you to know, not what you needed to know.

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i know one thing .. im still learning

All I can say is thank gawd for the internet ... oh yeah and a colleague down here that likes to waste money on toys .. yah know to play with and test ..

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Well, you guys need to understand that where we comes from, even $100 american dollars for a decent camera takes a month's salary from many people, so even the cheapest, crappies stuff is really the main choice we have.

 

100 American dollas a month? That is pretty pathetic. Where be this? My neighbours get at least 10 times that amount on Welfare. I think their goal is to have more and more kids to collect more and not work a day in their life. Beer delivered via Taxi, party all night, no vehicle of their own, geared to income housing, etc.

 

BTW, I picked up a CMOS Lorex camera from the local Canadian Tire long ago and stuck it in our server room. It is total crap but better than nothing. At least I know who goes in and messes things up. Paid around $140 CAD for it. It was not even worth returning to the store because of restocking fees.

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The big difference is the lux rating on the CMOS cameras which is quite high. But if you compare them to a CCD using a Sharp sensor its not that much different. If you compare it to a Sony CCD then its night and day. CMOS cameras from the orient start at $10 believe it or not and some decent ones for about $20+. But again never to be compared with the better CCD.

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originally posted by vitHoward:

Not to take issue, but CMOS is OLD technology. The first chip cameras that replaced tube cameras were MOS. The first color cameras were CMOS. They're like some of my old ties. They've been around so long that they're new again.

 

If I remember correctly, the first solid state imager cameras introduced into the U.K. around 1979, were certainly CMOS, and they were absolute rubbish (but still something of a novelty).

 

Shortly after, the first mono CCD cameras were launched as fairly stable usable units but only produced 190 TVL, with the next generation (early '80's) turning in a magnificent 280 lines res.

 

It wasn't until the 380 line B/W CCD's started to drop in price, which triggered the eventual demise of the established Vidicon tubed cameras.

 

I recall at least one MOS colour camera on sale in the mid '80's, which in all fairness wasn't too bad - not terribly sensitive, and a little bit too blue for some tastes, but on balance (obviously not colour balance ) it did serve a purpose.

 

A bit depressing to consider that twenty years on, the industry is still shifting shed loads of 380 / 420 line B/W cameras, albeit at virtually disposable prices.

 

Who says you can't halt progress

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hey rory,

 

give it another fifteen years in this industry, then I'll show you depressed

 

Would you settle for a 5 megapixel camera? .... may not have to wait so long!

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Waiting for the recording medium to catch up. Who cares if you've got 10,000 TVL if you can only record 300 of them?

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Sad but true Thomas .... and thoroughly depressing!

 

The technical limitations are surmountable, but the manufacturers I've spoken to are not yet ready to start thinking 'out of the box'.

 

Oh well, patience is supposed to be a virtue

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hey rory,

 

give it another fifteen years in this industry, then I'll show you depressed

 

Would you settle for a 5 megapixel camera? .... may not have to wait so long!

 

yeah, but cant do anything with it yet ...

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Give it five years. I suspect that's when we'll start seeing cheaper MP IP based cameras. Standard cameras will start cranking up TVL's if only to keep up. At which point recording medium will have to work out as well. It wouldn't shock me to see 2 or 4 TB drives by then. Put a bunch of those in Raid and who knows, maybe we'll start looking at lossless compression. Maybe some of that mythical CSI tech.

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i never saw a difference between the sanyo's claimed 520tvl, against another 480tvl cam ... actually i turned off that dipswitch cause it got a little too fake.

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Rory, the aperture correction circuits on the higher res. cameras do have a marginal but noticeable effect, but you have to use higher res. lenses to see the advantage. Basic 1/3" CS mount lenses just won't show any difference.

 

How about High Definition CCTV by 2010, what do you reckon Thomas?

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