Author Topic: Is there a relationship between true FOV and image brightness at a given magnifi  (Read 33 times)

Anton Yardley

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I have an Orion xx16g dob that has an 1800 mm focal length and an F ratio of 4.4. I have a set of older Meade series 5000 UWA and SWA eyepieces. I'm disappointed by the image brightness, even at 30-34mm eyepiece focal length. I expected that with 16 in of aperture that I would get very bright starfield images with these eyepieces. My optics are clean and free of dew. I'm just trying to understand why I don't have brighter images even at lower magnification. I don't think logically that FOV should impact brightness at a given eyepiece focal length but can anyone tell me for sure? Thanks!