Thread: How much IR cut is 'too much'?

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  1. #1 How much IR cut is 'too much'? 
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    I've been reading up on the likes of Mosaic and the Rawlite filter now including IR filtration. It made me curious to see what people's thoughts were on how much/how often they like to cut back on Infrared with the Blackmagic sensors. I have read that reducing IR too much can have negative effects on skin tones, for example (makes sense!).

    For instance, the 'holy grail' Hoya UV & IR Cut Filter - does anyone feel this cuts too much? Are people leaving it on all the time, or only reaching for it in certain circumstances? Whats the consensus on dealing with the levels of pollution without any ND?

    I realise this is something that doesn't have a clear cut answer, considering each shooting scenario may be dealing with IR Pollution in different ways. So I'm hoping it'll open up a wider discussion about levels of Blackmagic IR pollution in general and how subjective people are about IR levels.
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  2. #2  
    Senior Member PaulDelVecchio's Avatar
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    I use a Schneider 680. Anything less that I've tried isn't enough. Anything more would probably eat into the skin tones too much. The 680 might even be a tad too much but I think it's fine. Personal preference I guess.

    As far as shooting, around here in NY, I actually haven't come across a time when I absolutely needed it on all the time. I mainly throw it on when I shoot under a tungsten source. Otherwise I usually leave it off. If I'm outside under direct sun, it all depends on what NDs I'm using. I haven't found IRNDs that completely get rid of IR under tungsten on the BMD cameras. Not even the Firecrests.
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  3. #3  
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    I've been using the Firecrests IR for a while now on both the BMPCC and URSA. I mostly used it with Hoya NDs outside under sunlight. I don't find much difference with it on the lens or off the lens when shooting indoors so these days I mostly keep it on. So far the conditions have not let it eat into the skin tones.
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  4. #4  
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    I use the following and leave it on all the time. But...I only use those lenses indoors. I use my non-filtered 14 -140 outdoors.

    https://www.bhphotovideo.com/c/produ...6_Digital.html
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  5. #5  
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    I have the Schneider True-Cut 750 and haven't noticed any problems with it
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  6. #6  
    Senior Member rick.lang's Avatar
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    I use the Schneider True-Cut 715 IR Cut and did a test last September that showed it wasn't quite as effective as the B+W 486 MRC IR Cut on the 50mm APO prime. But for the 25mm, it may be better. Hope to retest next week weather and model permitting. Many people have observed on the 4.6K sensor, an IR Cut approach may not be necessary depending upon the situation. Very good quality IRND filters such as the built-in IRND filters on the URSA Mini Pro 4.6K camera may be sufficient. To that end I use the NiSi Nano IRND filters and showed pretty good results in the video posted on this forum last week. More to come!
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  7. #7  
    Senior Member Frank Glencairn's Avatar
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    You want a filter that starts cutting at 630ish with a steep slope, and totally cuts around 680 (red graph)
    IMHO anything that cuts at 715 (like the Schneider) or later, doesn't really cut it (pun intended)

    digital-video_diagramm.gif
    Last edited by Frank Glencairn; 03-14-2017 at 03:55 PM.
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  8. #8  
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    So the Schneider 715 isn't really cutting much of the IR pollution where you need it cut. Thanks Frank.
    Cheers
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  9. #9  
    ok, so according to the spec on b&h our beloved hoya irnd, is 700nm. From the hoya site you can see the graph that they show.
    The spec for the b+w linked to above comes closer to what Frank shows, bit probably still not quite there. I will stock woth my hoya as up to nw it has not being a problem for me.
    http://www.hoyafilter.com/hoya/produ...lters/uvircut/
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