Just wondering if any other member here have purchased one of Breakthrough Photography's ND10 filters? If so, have you noticed any issues with the filter coating?
I ordered one in an 82mm size at the end of May, after reading Brian @ TDP's excellent comparison of 10-stop NDs -
http://www.the-digital-picture.com/Reviews/10-Stop-Neutral-Density-Filter.aspx
It arrived in good time, is very nicely constructed, but was a little dusty straight out of the packaging. While using a blower rocket to puff the dust away, and holding it up to a light to check, I noticed there were a couple of areas on the filter where the coating seemed lighter, as if some of the coating had smeared off during the manufacturing process. Taking it outside and checking against a clear sky showed the same thing - two distinct areas showed a band of lighter coating. This was viewable looking through from either side (i.e. definitely not a reflection). The largest of the areas was maybe 18-20mm long by 5 or 6mm wide, so a noticeable size even on an 82mm diameter filter.
I emailed Breakthrough Photography, and received a quick reply from Graham there, who hadn't seen this before, and quickly offered to send a replacement. This arrived quickly (in the meantime I sent the first one back for inspection by B.P.), however the second filter exhibited a different problem - two points on the surface where there didn't appear to be any coating at all - a torch held behind the filter revealed two bright points of light. Think of the pinholes in a pinhole camera x2, about a 7 or 8mm apart, and 15mm in from the edge of the filter frame.
Another email to Graham, another replacement sent, and I returned the second filter (but not before snapping a quick photo of the problem, attached, showing a red LED torch positioned behind the filter).
The third filter arrived late this week, and I finally had time to open it today for a look. Like the first filter, this one has an area where the coating seems lighter, and a light source viewed through it is slightly brighter then when viewed through the rest of the filter. The band is smaller than on the first sample, thankfully, and not quite as light either - it's a closer density to what it should be, however it still points to some kind of manufacturing issue with the coating or whatever is responsible for attenuating the light.
Whether it will have any visible effect on image I've yet to determine. I suspect the first sample might have, the second on definitely would have, but this third one might be ok. Given that I've now had three samples, all with potential issues, I suspect I'm not the only one who might have purchased one of these filters exhibiting this issue. Anyone here have one they'd be willing to check?
Cheers,
d.
I ordered one in an 82mm size at the end of May, after reading Brian @ TDP's excellent comparison of 10-stop NDs -
http://www.the-digital-picture.com/Reviews/10-Stop-Neutral-Density-Filter.aspx
It arrived in good time, is very nicely constructed, but was a little dusty straight out of the packaging. While using a blower rocket to puff the dust away, and holding it up to a light to check, I noticed there were a couple of areas on the filter where the coating seemed lighter, as if some of the coating had smeared off during the manufacturing process. Taking it outside and checking against a clear sky showed the same thing - two distinct areas showed a band of lighter coating. This was viewable looking through from either side (i.e. definitely not a reflection). The largest of the areas was maybe 18-20mm long by 5 or 6mm wide, so a noticeable size even on an 82mm diameter filter.
I emailed Breakthrough Photography, and received a quick reply from Graham there, who hadn't seen this before, and quickly offered to send a replacement. This arrived quickly (in the meantime I sent the first one back for inspection by B.P.), however the second filter exhibited a different problem - two points on the surface where there didn't appear to be any coating at all - a torch held behind the filter revealed two bright points of light. Think of the pinholes in a pinhole camera x2, about a 7 or 8mm apart, and 15mm in from the edge of the filter frame.
Another email to Graham, another replacement sent, and I returned the second filter (but not before snapping a quick photo of the problem, attached, showing a red LED torch positioned behind the filter).
The third filter arrived late this week, and I finally had time to open it today for a look. Like the first filter, this one has an area where the coating seems lighter, and a light source viewed through it is slightly brighter then when viewed through the rest of the filter. The band is smaller than on the first sample, thankfully, and not quite as light either - it's a closer density to what it should be, however it still points to some kind of manufacturing issue with the coating or whatever is responsible for attenuating the light.
Whether it will have any visible effect on image I've yet to determine. I suspect the first sample might have, the second on definitely would have, but this third one might be ok. Given that I've now had three samples, all with potential issues, I suspect I'm not the only one who might have purchased one of these filters exhibiting this issue. Anyone here have one they'd be willing to check?
Cheers,
d.