10-31-2017, 09:08 PM
Quote:I guess it's a question of available space in the camera body. Plus, it would be an additional layer of glas wioth at least some amount of refraction, so it'd be part of the whole optical system. That's why I guess it would have to be two filters, a clean one and the ND one in order to keep the whole optical system at the same level (similar to high-end tele lenses, that allow drop-in filters and need to have a clean filter in there).
In terms of dust, I'd be afraid that it just moves the dust issue to a different layer. However, a protective glass cover is what Sigma uses in their own DSLRs, so in principal the idea seems to work.
Valid points, especially the two filters. I imagine a half darkened stripe of optical glass to be moved from left to right. Adding not only one, but two moving surfaces (dust and wear, particles, oil...) in a very small volume of a camera body. Making it close to impossible to focus because of 10 stops amplification (or less, Fujifilm's ND filter coming with the 56/1.2 APD is ND8, so only 3 stops).
Sigma DSLR? Or the mirrorless sd quattro types? Anyway, most mirrorless cameras do have a glass element in front of the sensor.
See Lensrentals Blog:
The Glass in the Path: Sensor Stacks and Adapted Lenses
Sensor Stack Thickness: When Does It Matter?
Sensor Stack Thickness Part III: The Summary
A Thinner Sensor Stack