- A great replacement for your damaged or broken lens
- Suitable for cameras with standard mount
- Focal Length: 25mm/1.0in
- Sensor Size: 1/2"
- Mount: CS
- Aperture: F 1.6
- Angle of View: 20.0°
- Focus: Manual
- Size: 30 x 29mm / 1.2 x 1.1in (Dia. x H)
- The lens is particularly of benefit in cameras
- This lens is being designed for 1/3 inch camera and mount is CS type
- It is a professional lens of expert level
What Is the Iris on a Camera Lens?
- Some cameras, usually point and shoot, according to the website photxels.com, have a fixed-aperture lens. This means the iris of the lens is not adjustable but rather fixed in size. The camera adjusts in other ways--like shutter speed or light sensitivity of the sensor-- for changing light conditions.
- The mechanical iris is made up of a number of leaves or pieces that are moved to decrease or increase the size of the opening or the aperture of the lens. The larger the aperture or opening, the smaller the f-stop number used to describe it. An f-stop of 2.8, for example, would have a larger opening in the iris than an f-stop of 5.6.
Lens Sweet Spot:
- Most lenses have an aperture where the focus and picture quality is optimal. This is often found by trial and error by the photographer, although the website commonsensephotography.com says the sweet spot is often close to f-stop 8 on many lenses.
Automatic Iris Control:
- Auto-iris cameras continually adjust the aperture of the lens adjusting to changing light conditions automatically. This is more common in video and security cameras than it is in still cameras. The auto-iris feature will make the transitions required during the changing light of a day in a security camera setting, allowing the officer to have an acceptable view of the scene throughout the day.
- Lenses where the iris opens to a large aperture are said to be fast because they allow more light through the lens and can utilize faster shutter speeds. Fast lenses are often associated with indoor, portrait and sports photography. An iris openings of f-stop 2.4 is considered fast when associated with most modern digital cameras while an f-stop of 1.4 was considered fast for 35 millimeter film cameras.