« on: October 10, 2014, 01:00:03 AM »
Sorry i was away, I was using an after market flash extension cord, I was around 120th I think and yes I had a B&W pro filter on.
Hmm, makes me think less of B&W pro filters. Those things should be multicoated to prevent this.
Sorry to be obtuse here, but when light hits surface of the glass on both surfaces, there is reflection, and refraction. But in the glass there is transmission and absorption. Some light will always be lost to being absorbed. It makes heat. So
Even the best multicoating won't completely stop this phenomenon. Think of it this way: if you can *see* a piece of glass, that necessarily means it reflects some incident light, otherwise it would be completely invisible to you. To be immune to this phenomenon, you'd need a glass that would look invisible and fail to show any reflected light over a wide range of viewing angles.
The fact that the flash is throwing a ton of light directly into the lens at an angle that is not image-forming virtually guarantees that there will be a lot of veiling glare. That non-image-forming light bounces off the lens sub-barrel and diaphragm, comes back out, hits the filter, and because it's a macro shot, ends up forming a very nice detailed ghost of the inside of the lens.
Sure, without doing something more drastic, such a reflection is pretty much guaranteed. I'd love to see a filter like this with a nanocoating. Where multicoating can cancel out enough reflections to allow up to 97% transmission, that's still 3% reflection. A nanocoating, on the other hand, can simply prevent reflections entirely, resulting in 99.95% or better transmission. I bet a nanocoated UV/protect filter would have handled this situation nicely.