Jman13
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So I'm hoping someone on here has this lens and can answer a question for me. I got my copy today, and have done some initial testing. Overall, it seems quite good. Very sharp, even at 5x magnification (though f/4 is the max before diffraction kills the image), though I've noticed that the lens seems very prone to some sort of internal reflection when set to between 4x and 5x magnification. In a lot of cases, there is a loss of contrast and two sort of slightly curved bands of brightness. Almost looks like veiling flare, but even wrapping the end of the lens in black velvet flocked paper to shield doesn't change it...it just seems to depend on how the light enters the front of the lens. In some cases, it's not perceptible at all, even at 5x...at others, like the quick test shot below, it's very visible. If I reduce magnification to 4x or lower, it seems to recede and doesn't seem to be an issue at all in that range.
For those that have this lens, have you experienced this? Is it just something I have to be aware of and try to avoid when I see it?
I did look through the lens from the back when extended to 5x, and I think it might be the reflection of light off the grease on the inner barrel, as when it's extended to 5x, I can see reflections on the sides, and sure enough, when collapsing the lens to 4x and shorter, those reflections disappear. So I think it's just a circumstance of the lens design, but none of the reviews mention it.
As you can see in this test shot (stack of 10 images), though, it isn't in all situations, as this is at 5x magnification:
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