Jump to content
UltravioletPhotography

[Filter Test] B+W 092 IR-Pass: Test for Red Leak


Andrea B.

Recommended Posts

Just for the heck of it I stacked the Baader UVIR-Cut filter and the Baader 610 Red Longpass Filter over my B+W 092 IR-Pass Filter to try to capture the visible red "leakage".

There are no surprises, but here it is anyway.

 

Equipment: D600-BB + 105/4.5 UV-Nikkor + Filter Stack( 092IR, UVIR-Cut, 610 Red ) + Sunlight

Exposure: f/11 for 1/13" @ ISO-200

 

White Balance: Preset3 which is an in-camera, visible, white balance preset made under the Baader UVIR-Cut filter in sunlight.

Conversion: Photo Ninja in which a D600-BB visible colour profile was assigned but no other edits were made except for a bit of blowout control and some sharpening.

Comment: I do not know precisely how tight this filter stack is. There might be a bit of IR getting through or maybe a bit of other visible colour leaking.

d600whiteStd_092IR+uvirCut+redPass610_sun_105uvNikkor_2015.10.06wf_40322pn.jpg

 

Here a white balance was made on the middle 99% reflective white standard.

d600whiteStd_092IR+uvirCut+redPass610_sun_105uvNikkor_2015.10.06wf_40322pn2.jpg

Link to comment
If memory serves, the O-92 allows much more red light through than the Hoya R-72, its 50% point being around 700 nm instead of 720 nm.
Link to comment

Here is the histogram of the raw file.

 

Between EV -1.5 and EV 1, there appears to be only R.

From EV -1.5 down to EV -3.3, there is R and G.

From Ev -3.3 down to EV -5 we see R, G and B.

Below Ev -5 there is no more R.

 

Can we interpret a colour from this histogram? Is the leakage Red? Or is it mostly Red?

 

Screen Shot 2015-10-20 at 3.17.59 PM.jpg

Link to comment
I have used the 092 with ordinary black-and-white film as a red filter--about a 5-stop filter factor, as I recall. And, obviously, you can see through it. I would call it a deep-red filter rather than a true black-IR filter. It in fact passes a bit too much red to work very well with Efke's IR film.
Link to comment
Yes, the 092 is definitely a Red + IR filter. I have it listed that way in the Stickies. "-)
Link to comment

However, it frequently is falsely listed as being an R-72 equivalent.

 

I have at least one sample of a B+W O-92 that you cannot easily look through, and it behaves much the same way as the genuine Hoya R-72. So not really certain what the maker aims to achieve with these filters.

Link to comment

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
×
×
  • Create New...