Rosko Posted May 28, 2008 Author Posted May 28, 2008 Thanks all for your suggestions - - a great help. I'm going to have a dem with a 540 TVL Camera and 50mm lens to see how effective that'll be. Obviously if that's no good we'll have a better idea then of how to improve things. thanks again Rosko
james.wilson Posted May 28, 2008 Posted May 28, 2008 From my own experience I always recommend one of these http://www.derwentcctv.com/home/index.php?...5&show=true to suit the application, but 80m is too far. You will need to consider speed of target and angle of capture ideally you want to be straight on and mounted the cam at low level. Obviously your range will help with this. Assuming its not a high speed capture id use local low level IR lighting (ie local to the scene) a 1/250 shutter speed, DD lens and a 120mm lens on a 1/3 cam. This will give an approx scene width of 3m. your 50mm lens on a 1/3 cam will give a scene width of 8m which is too wide for reg capture after recording losses securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
arfur mo Posted May 28, 2008 Posted May 28, 2008 Thanks all for your suggestions - - a great help. I'm going to have a dem with a 540 TVL Camera and 50mm lens to see how effective that'll be. Obviously if that's no good we'll have a better idea then of how to improve things. thanks again Rosko i don't know if you have enough money in the jobs budget, but why not take a varifocal lens, least that way one trip will have a better chance of success, and the saving in labour time will help compensate. when i'm not sure what i will get i set up a dummy location over the approximately same view, fiddle about as needed then when happy take it to site. saves getting there and finding your short of a vital item to B) regs alan If you think education is difficult, try being stupid!!!!
james.wilson Posted May 28, 2008 Posted May 28, 2008 AFAIK alan varifocals only go up to 50mm, after that he is going to need a zoom lens. Id go for something bigger than 80mm and upto 120 if i could. He knows the distances but if you could get a varifocal / manual zoom lens that goes upto 150mm then thats the way forward. Do you know of one? James securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
SUBS Posted May 28, 2008 Posted May 28, 2008 Hi there - - I'm intending fitting a camera to view cars and lorries coming into a yard and it would be a bonus if on occasion we could read the number plate. The distance involved is 80 metres - - has anyone any advice on what size lens I should use? - - and any other relevant points.Thanks assuming you have a 1/3" Camera Distance in Metres X 4.8 / Width of target. so No. Plate should fill over half the screen if you use a 64mm lens. Recording No. Plates is a pain at the best of times, and at this distance even a little bit of wind will shake the image so much you wont be able to use it. You'll also need to consider fitting a peak white invertor.
james.wilson Posted May 28, 2008 Posted May 28, 2008 subs i calculate that a 64mm lens will give a scene width of 6m at 80m. If you want the number plate to fill half the screen you will need a scene width of less than 1m which would need a 400mm lens securitywarehouse Security Supplies from Security Warehouse Trade Members please contact us for your TSI vetted trade discount.
SUBS Posted May 28, 2008 Posted May 28, 2008 subs i calculate that a 64mm lens will give a scene width of 6m at 80m. If you want the number plate to fill half the screen you will need a scene width of less than 1m which would need a 400mm lens Your absolutely right, bloody dell boy calculator........ Wouldnt want plate to fill the screen though, have to allow for car being a couple of feet either side of centre. I dont think you'd have found a 64mm lens anyway, probably the only way is to move the camera.
satsuma01 Posted May 28, 2008 Posted May 28, 2008 Your absolutely right, bloody dell boy calculator........ Wouldnt want plate to fill the screen though, have to allow for car being a couple of feet either side of centre. I dont think you'd have found a 64mm lens anyway, probably the only way is to move the camera. no a certain company do a lens that it 5-100mm lens as i know cause ive used one on a pub car park, and thats not zoom LENS-AUTO IRIS DD 5-100MM ( CCT345 ) "If you carry your childhood with you, you never become old. Why rush to end life when happiness is in the blissfulness of childhood innocence.""We all die, the goal isn't to live forever, the goal is to create something that will." 07475071344
camerabloke Posted May 28, 2008 Posted May 28, 2008 http://www.manchestercctv.com/lensauto-iri...663581761a8dd8e Eucam Security Systems 0845 4630 746 www.eucam.co.uk
Alpat Systems Posted May 28, 2008 Posted May 28, 2008 Vista do a 20-100mm DD 1/3" http://www.norbain.co.uk/downloads/datashe...lenses_July.pdf alternatively you could use: Samsung SDZ-330 - 1/4" Low Light & WDR 30X Optical Zoom camera 3.3-99mm, weve used these a few times for number plate recognition when the customer didn't want to pay for a full ANPR system. http://www.samsungcctv.com/product/file_da...-330.E.cata.pdf
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