Guest Guest_Chris_* Posted February 19, 2005 Share Posted February 19, 2005 Hi, can anyone shed some light on this problem. I have upgraded my old and simple CCTV camera's to a new system with Vantage VGC752 camera's. I have fitted F1.6/5-40mm lens to the camera's but get a black fishbowl effect ie a black round ring around the picture unless I zoom right in on a object. If I zoom out the black ring around the picture appears, although the picture itself is clear you lose alot of the image to the ring of darkness. As this is the first time I have ventured into this type of camera, I cannot get to the bottom as to the reasons why this is happening. There are numerous settings which can be changed on the camera but I do not want to start making any alterations until I know what I am altering. Any assistance would be really appreciated. Thanks Link to comment Share on other sites More sharing options...
norman Posted February 19, 2005 Share Posted February 19, 2005 Use a lens spacer, I beleive the lens is too close to the CCD. Nothing is foolproof to a sufficiently talented fool. Link to comment Share on other sites More sharing options...
Guest Guest_Chris_* Posted February 19, 2005 Share Posted February 19, 2005 Use a lens spacer, I beleive the lens is too close to the CCD. 41072[/snapback] I have tried several combinations of spacers but when I try the spacers I am unable to focus the image, all I get is a blur as an image. Its driving me mad, I never thought that upgrading my camera's was ever going to give me these problems. I have bought two Vantage day / night camera's with complete with lenses and have been unable to get anything near a satisfactory image. I also bought two cheap dome camera's from hong kong, with ir led's and these work superbly ?!? Thanks in advance for all replies and advice. Link to comment Share on other sites More sharing options...
Rich Posted February 19, 2005 Share Posted February 19, 2005 Hi Chris There are 2 types of lenses, C-mount and CS-Mount CS mount fittings are newer than C mount, basically its the distance of thread size on the back of the lens, C-Mount is 17.526mm in depth and CS-mount is 12.5mm. C-Mount were for 1inch chips. If you were using C-Mount lenses on CS-Mount cameras you would use the spacer, And move the lense away from the camera by fitting a 5mm C-Ring or C- CS mount adapter. Unfortunately in your case it sounds like its the other way round, you are fitting CS-mount lenses to a C-mount camera, as far as i know you will have to replace the cameras or lenses to match them up. Be carefull not to crush the CCD when screwing on the lens : If I am wrong then the lenses you have will be C-mount ,and the cameras CS-mount, So a ring should solve it. Your cheapest option would be to get some rings and see if they do infact solve your problem, or check your cameras properly to see if they have universal mounting settings, they may do if they have back focus adjustments. Hope that helps you out. Link to comment Share on other sites More sharing options...
Rich Posted February 19, 2005 Share Posted February 19, 2005 If you have tried a ring and altered the back focus as Peter suggested and still cang get a decent image then what I have said is probably correct, and some new equipmnet you will need Link to comment Share on other sites More sharing options...
ian.cant Posted February 19, 2005 Share Posted February 19, 2005 Youve bought 1/3" lens and fitted them to a 1/2" camera i would think! Otherwise What Rich says is likely to be right. Link to comment Share on other sites More sharing options...
Guest Guest Posted February 19, 2005 Share Posted February 19, 2005 Youve bought 1/3" lens and fitted them to a 1/2" camera i would think!Otherwise What Rich says is likely to be right. 41081[/snapback] Oops it would appear that is exactly what I have done.... 1/2" camera, 1/3" lens... I just wish I had found this great resource of information that is on this site prior to making my purchases.. live and learn. Thanks everyone for all your advice. One last question, where is the best resource for 1/2" lenses ? Link to comment Share on other sites More sharing options...
Rich Posted February 19, 2005 Share Posted February 19, 2005 Youve bought 1/3" lens and fitted them to a 1/2" camera i would think!Otherwise What Rich says is likely to be right. 41081[/snapback] Give that man a balloon on a stick!! Link to comment Share on other sites More sharing options...
Guest Guest_Chris_* Posted February 25, 2005 Share Posted February 25, 2005 Thanks for everyones assistance... Can anyone point me to a resource in order to purchase 2 x 1/2" 4mm Auto Iris lenses ? The lower cost the better as this project is now running well over its initial budget. How much should this type of lens cost ? Link to comment Share on other sites More sharing options...
Rich Posted February 25, 2005 Share Posted February 25, 2005 http://www.norbain.co.uk/go.php?structureI...amily=LE&type=A Norbain will have what you want, try them. If your not trade, then someone here may sell you a couple. Have you ever fitted/worked on CCTV before, you say your system, and the project, is the stsyem your own? If so, and you dont mind waiting then try ebay. Link to comment Share on other sites More sharing options...
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