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  1. W

    Wide flat field and edge sharpness an illusion?

    The term "sweet spot" is usually used to describe a shop selling sweets but in optics it generally meant the area in the centre of the field that is relatively free from aberrations. The experiment of stopping down the objective effectively means you are only using the best part of the...
  2. W

    Wide flat field and edge sharpness an illusion?

    I don't tend to get blackouts when I look at the field edge but I only tend to look right to the edge of the field so see if it's flat, check the distortion profile or compare the field of view between 2 optics - it doesn't happen very often! When I do look at the field edge it's a conscious...
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