Member Discussion
Will This Analog Zoom Lens Work With MP Cameras?
Lenses are not "analog" or "megapixel", they have a resolution rating, and the rating of your lens should ideally meet or exceed the specifications of the camera you're attaching it to. Well, actually, all lenses are "analog" in a sense ;)
The spec sheet for this lens does not lists its resolution (usually a lp/mm (line pairs per mm) number). So it's reasonable to assume it is only rated for D1 resolution.
A good D1 lens will have a resolution of around 50 lp/mm. You'd want 100 or more for 720p/1MP, around 150 or more for 2MP, and so on.
The lens you list will "work" with a megapixel camera (assuming it mounts to it, image sensor physical size is appropriate, etc.), however it may prevent the camera from capturing images at its full potential.
Thanks for the quick reply!
The reason I bring up the question is that I would connect the analog output of the camera to a monitor for live viewing. The network side of the camera would be recorded by a Milestone server. So if I understand correctly, the worst possible outcome would be recording at D1 resolution provided the lense fits properly on the camera?
Yes, the worst possible output is that you put a "cheap" lens on an "expensive" camera, and the output is limited to the lowest common denominator (the lens in this case).
No matter what lens you use, the image on the monitor probably won't look that different, but the recorded video will likely show detail enhancement with a better lens. This of course would be more obvious for smaller objects. A face or license plate filling the entire frame would probably be recognizble with any lens, but at 100' away might only be recognizable with a proper lens matched to the camera (assuming that at 100' you have enough ppf on target to recognize anything at all...).
Boy, that's an old model! It's a 1" format so will cover most megapixel sensors (the focal length will still be correct despite this), it's C mount so you might need a 5mm spacer ring on modern IP cameras (most likely to be CS mount) and the resolution will need to be considered carefully; the spec sheet doesn't detail the resolution but I expect it is around 800-1000TVL equivilant. You should also look at how you're going to drive the lens and whether you need the preset functions, not sure who does telemetry receivers for IP systems... I'm sure someone from Computar (CBC) will fill in the gaps!
The lens will be driven by this remote control periscope:
It's on the top of page two. The one I'm actually am working on is the RCSS-3000. I called the company, and they said it's the same as the one in the catalog with the exception of the newer one is lower profile.
A Panasonic WV-CL924A was originally connected. During use, the coax cable was pulled from the back of the camera ripping out the electronics on the back of the camera. I managed to fix it short term but I'm looking to eventually replace the camera.
Nice! Looks like a lot of fun, the controller should drive the lens and focus fine then. The presets won't be supported, looks like a simple manual controller. Again I would add the mirror quality to my earlier comments, along with Brian's, regarding resolution degradation - the optimum resolution of the megapixel camera will be limited by the lens resolution then possibly further degraded by lens imperfections/abberations. Be interesting to know how well it works in the end.
Do you have to use that lens? Doesn't Computar have MP zoom lenses?
John,
I have the lense. Computar does have MP lenses but I'm trying to replace the camera part of the periscope. See the periscope below. The electonics of the original camera got ripped out of it when the coax cable got caught on something (I assume) when it was rotating. I pieced together the original camera and it's working for now but it will need to be replaced soon.
What MP is the camera/imager? 1.3MP? 3MP? 5MP? 10MP?
The amount of detail loss will increase with higher MPs. However, at 1.3MP with an analog lens, I do not suspect it will be great.
We did such a test in our MP pinhole shootout here.
I need to buy that. I'm thinking a Sony IPELA SNC-CH120 which I think is 1.3MP. I don't want to spend much more then $500 for the camera. I've used a few of these in other applications and have been pretty happy with them.
I'm going to the use the analog out to a monitor for live viewing and the IP side to stream to a milestone server. I'm not at all experienced with lenses but I know the computar zoom lense we have been talking about is C mount and the original panasonic analog camera that came with the periscope is a CS mount. I assume there is an adapter between the zoom lense and the camera?
I have been trying to figure out what type of lense the Sony uses but I'm assuming it's CS?
Thanks everyone for the reples. They have been helpfull !!
Will it work? Yes. Will it work well? Probably not, depending on the camera.
Since there's absolutely no information on the quality of glass used to make the lens, you cannot assume the glass is good enough to shoot through. This will be an even bigger issue due to the multiple elements required to make a zoom lens, especially a zoom lens with such a narrow field of view and such a compact barrel. In short: it'll probably be blurry, and never focus right.
See here: http://ipvm.com/report/the_importance_of_megapixel_cameras
OK I remember selling this model when I worked for CBC (Computar) in the ealry 90's and it was top quality in terms of optics, it sold for over $1000 as I recall. As it is a 1" format designed for tube cameras the resolution should work well for a 1.3Mp camera; with most CCTV grade optics the resolution decreased the further you get from the centre, as CMOS sensors are so much smaller in format they only use the very best part of the optics - the centre. So I'm fairly sure the results will be acceptable for the camera spec.
I would pick a camera with as large a sensor as possible, but below 1" obviously.
This will maximise the resolution of your system using this lens.
For example. Using this lens.. A camera with a 1/2" sensor will give better resolution than a camera with a 1/4" sensor.
I finally got to the point in the project where I replaced the old panasonic analog camera with the Sony IPELA SNC-CH120 I did some testing today and it's working great!! Thanks to all who replied!!
With the original lens?
Yes! Works great! Was zooming into license plates well over 200 yards away.
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