Tag Archives: analysis

Quick Pentax Lens Test: Parfocal or Varifocal?

I did a quick test on three lenses that I have to see if they are Parfocal or Varifocal. If you are unfamiliar with those terms, Parfocal is a type of zoom lens that does not have focus shift when the lens is zoomed throughout the focal length range. This is a great feature for video work because the photographer can achieve focus and zoom without the need to refocus. … Continue reading

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Camera Lens UV Filter Test: Does coating make a difference?

I decided to do a quick test to see how my collection of 58mm UV filters damage image quality. I also took an image without a filter to see what difference using no filter makes. Why do I personally use filters? I want the added protection that a filter brings as well as the simplicity of cleaning a filter instead of the front element of the lens. I occasionally take … Continue reading

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