Cuchulainn
Suspended / Banned
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- Name
- Brian
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Well, that was a good use of an evening. I had a large spot of dust (~1mm) dead centre on the inside of the rear element of the 56mm. Looks like it's something that's happened to a few lenses based on some googling of the problem. Thought about sending it in for repair, but as it's out of warranty, reckoned undoing a few screws wouldn't hurt! Turns out the final element in the 56 is easy to remove as it's bonded to its housing. All cleaned up nicely with just the blower and an anti-static brush. Lens is as sharp as ever and no dust bunnies any more!
Element was interesting - looked like a very thin (~1mm), very long (~1000mm) focal length meniscus lens. Wonder if it's primarily aberration correction for low f-numbers... Definitely not something I'd seen in similar lenses, though it did remind me of the filters that are a required part of the optical path in some reflective lenses.
Element was interesting - looked like a very thin (~1mm), very long (~1000mm) focal length meniscus lens. Wonder if it's primarily aberration correction for low f-numbers... Definitely not something I'd seen in similar lenses, though it did remind me of the filters that are a required part of the optical path in some reflective lenses.
Moon





