[Leica] M8 + IR Filters - comparisons

[red735i at verizon.net (Frank Verizon)]

According to the specs I read from B&H, the B+W 093 filter transmits  88% of 
light at 900 nm ( blocks below).  The 092 transmits 90% at 730nm.  

Would love to see the a-b-c results and understand the loss of light of 
each...

Frank Filippone
Red735i at verizon.net

Well my 092 "dark red" B+W F-Pro filter just arrived from B&H via UPS.
A very large box for a tiny 46mm filter.

The first thing I did was pointed the lens,
with the 093 filter still on the camera,
out the west office window.
Auto exposure indicated:
ISO 640
f:2
1/15th sec

Then I switched to the 092 filter.
Pointed it out the same window; similar framing.
Auto exposure indicated
ISO 640
f:2
between 1/180th 1/250th sec

A whopping 3 - 4 stop difference.

I was pleasantly surprised;
as this filter will make hand held,
lower ISO speeds,
much more practical.

I then stepped out on the front porch
and made two exposures,
one focusing on a light post,
about 7 - 8 meters away,
one making an IR focus adjustment,
Sharpness results inconclusive.

Need further, more precise, tripod, etc. testing.

Still achieving dramatically dark skies with good cloud separation;
though definitely not as dramatic as the 093.




Frank Filippone
Red735i at verizon.net