redliner 0 Posted February 17, 2011 Hey, I always used DC auto Iris lenses outdoors. One day one of these lenses broke and because I didn't have one, I put a simple 4 mm manual iris cheap lens. After viewing the night time recording I can't see any difference. If what that the cheap lens is even sharper that autoiris. Can anyone tell me what is it about autoIris that actually makes it better. Camera I used them on is Samsung sdc-415. What is more with varifocal autoIris I sometimes get a sharp picture in the center and blurry on the edges or vise versa. Share this post Link to post Share on other sites
Soundy 1 Posted February 17, 2011 Auto-iris merely allows the camera to close the iris in bright lighting conditions, thus extending the range of lighting the camera can handle. Most cameras can control exposure to some degree using electronic shutter control, but they're still limited in bright light by how much light the sensor will actually handle. If there's not a wide range of lighting between day and night, you may not see a difference. Fixed-focal lenses tend to use much simpler optics than varifocal, which IN GENERAL means they have sharper images... but actual lens design and construction quality plays into things a lot as well (ie. a well-built varifocal lens will usually be sharper than a cheap fixed lens). Overall, auto vs. manual or fixed iris has little to do with this. What lenses are you comparing, specifically? Share this post Link to post Share on other sites
SEANHAWG 1 Posted February 18, 2011 What I have noticed is, if you have a well lit up area at night, you wont be able to tell much of a difference between manual iris and auto iris lenses, especially if you put them on a day/night cameras. Its the areas with very low light at night in which you will be able to tell the difference. But that Samsung is a good day/night camera and that has alot to do with it too. Share this post Link to post Share on other sites
Soundy 1 Posted February 18, 2011 What I have noticed is, if you have a well lit up area at night, you wont be able to tell much of a difference between manual iris and auto iris lenses, especially if you put them on a day/night cameras. Its the areas with very low light at night in which you will be able to tell the difference. How's that, now? A wide-open iris is a wide-open iris at night, regardless of whether it's auto or manual. Share this post Link to post Share on other sites
SEANHAWG 1 Posted February 19, 2011 How's that, now? A wide-open iris is a wide-open iris at night, regardless of whether it's auto or manual. Sure that makes sense if you have you always had your manual iris wide open but thats not always the case. Share this post Link to post Share on other sites
