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TeleVue 22mm Nagler Type 4


The TeleVue 22mm Nagler Type 4 combines the 82 degree apparent field of all Nagler eyepieces with a generous 19mm of eye relief. This eyepiece features a movable upper ring holding the eye cup, which the user may adjust up or down to his or her own comfort level. This is a popular low-power eyepiece among owners of large (16+ aperture) Dobsonians, and it is useful in a wide variety of telescopes.


Item #ProductStock StatusPriceShipping
EN4-22.0TeleVue 22mm Nagler Type 4
In Stock - Ships Same Day (business days) This is "live" inventory data. If it says in stock, you can believe it.
$525.00
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Optical Specifications: TeleVue 22mm Nagler Type 4
Focal Length 22 mm
Apparent Field-of-View 82°
Eye Relief 19 mm
Physical Parameters
Weight 24 Ounces
Barrel Diameter 2 Inches
Eyepiece Calculator
Enter at least two of your telescope's specifications:
*Focal Length (mm):
*Aperture (mm):
Focal Ratio (f/):
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True Field:
 
Exit Pupil: <p>Exit pupil represents the diameter of the column of light exiting the eyepiece. Magnification is simply the ratio of telescope aperture to exit pupil. Fox example, using a telescope with 100mm aperture and an exit pupil of 2mm yields a magnification of 50X.</p> <p>There are both upper and lower limits to the useful range of exit pupils. The typical human eye pupil dilates to a maximum of 7mm when fully dark adapted. This figure decreases with age. Using an exit pupil that is larger than this upper limit simply spills the light onto an area of the eye not capable of receiving data. At the opposite end of the range, a smaller exit pupil means less area on the eye is collecting data. Images brightness decreases with decreasing exit pupil. Deep space objects grow dimmer rapidly as the exit pupil falls below 1 mm. The planets also start to become noticeably dimmer when the exit pupil falls much below 0.5 mm.</p> <p>Our eyepiece calculator provides warnings and error messages based upon the value of the exit pupil. These are intended to be guidelines as opposed to hard rules. There is no harm in violating these gidelines, but your enjoyment of the telescope may be diminished if you do. </p>