Infrared Help Please (2 pics with 5700)

Started Jul 12, 2004 | Discussions thread
ookpik Regular Member • Posts: 172
Re: Infrared Help Please (2 pics with 5700)

Thanks, Kamran. This confusion between R72 and 89b shows up quite a bit. As your pictures show, there has to be more than just a label. The "R72" designation seems to be associated wit Hoya and it appears that it blocks all light below 720 nm ( ). But so, apparently does the 89b (

). Then,

shows a threshold for a "B&W 89b" around 690 nm. Is it possible that all "89b" filters are not created equal? Which reminds me, where did you get your 89b filter?
Thanks again,


Kamran wrote:

ookpik, I also read that misleading text somewhere on the net when
I was buying R72 (and 5700). Anyway, now I use both the filters,
and for sure they are different :). R72 is much darker than 89b and
filters different wavelength.

Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow