It’s easy! EPFL = eyepiece focal length. How to use the Eyepiece calculator. True Field of View: The circle of sky that you see when you look through a telescope or binoculars. To find the field of view (fov) for a camera lens or telescope enter the focal length (fl) and click the calculate button. You can select or convert the fov result format in either degrees-minutes-seconds format or decimal degrees below. According to apparent field of view, we should get a wider field of view with the 72 degree version. Using the Drift Method to Calculate Field of View ... - Added area calculations - Replaced FOV formula with higher accuracy version for wide angle lenses v0.80 - First public release. TFL = telescope focal length. Vignetting and field of view, coma, focal depth, thermal shift of focus. FS = eyepiece field stop. AF = apparent field. Astrophotography and CCD Calculator Features. You can also enter in the specifications for any items that aren’t listed here. This is the amount of view you see through your scope from right to left at that distance. If you have healthy eyesight you can probably see about 120° in front and slightly to the sides, so basically a third of what is around you. As magnification is decreased, FOV goes up. Field of view (FOV) is measured in feet at 100 yards. This is your field of view. Assuming the field stop of the 22mm T4 Nagler is 31.1mm as claimed and that it has been calculated in order to yield the correct amount of true field, then an apparent field of 31.49mm is derived from an 82° apparent field. Will the eyepiece that produces the widest field of view please stand up! True field of view = (57.3 x field stop diameter) / telescope focal length. As a rule of thumb, a telescope’s maximum useful magnification is 50 times its aperture in inches (or twice its aperture in millimeters). Field stop and focal length measurements must be in mm for this formula to work. For DSLR and SLR Cameras. Custom coordinates Generate an image of any part of the sky from the STScI Digitized Sky Survey. Select camera: ... Focal lenght of the telescope: [mm] Fill next fields manually if your camera is not listed: Chip size: x [mm] Pixel size: [um] Result: Your FOV: Planetary section with sampling rate, required barlow, video times for planets. We look through a telescope and see a small are of sky and this is the field of view … Generally, the lower the magnification, the wider the field of view. Field Of View Calculator. Deep Sky section with sampling rate based on seeing, required barlow, etc. Basic parameters such as FOV, resolution, airy disk, image scale, etc. It is what is in front of you that you see best. Click on a telescope, camera or combination in the yellow boxes below to preview how large near and deep space objects will appear and whether the sampling is good for astrophotography. Input your telescopes aperture and focal length and any extra reducer/barlow if … The Hubble Space Telescope Orion Treasury Project Team. CCD FOV calculator. As magnification is increased, FOV goes down. With this eyepiece calculator tool you can easily evaluate how a certain telescope-eyepiece combination will work and how large the field of view (FOV) will be compared to known objects. To determine the actual or true (sometimes called angular) field of view that each eyepiece produces in your specific telescope is simple.