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IR filter for BMCC
  • theconformisttheconformist

    Recently purchased a BMCC and have a question regarding IR filters. My plan is to get an IR filter and use it in front of the ND filters I already have though I understand it's probably better to just replace my whole set with IRND's to reduce the chance of ghosting, etc but I can't afford to do that. I've heard IR or IRND filter is recommended passed 1.2, my question is if there is a negative effect to using the IR when it is not needed? Like if I just leave it in the matte box all the time or use it with .6 or .9 ND filters?

  • 26 Replies sorted by
  • vicharrisvicharris

    Not the pocket right?

  • theconformisttheconformist

    @vicharris No, I went for the Cinema Cam, but also have a Pocket - does the Pocket suffer IR pollution as well?

  • vicharrisvicharris

    Yep, not as bad but it's there.

  • JuMoJuMo

    If you leave it when you don't need it, you'll lose a little bit of light transmission and you MAY incur a color cast (depending on the IR cut filter).

  • Vitaliy_KiselevVitaliy_Kiselev

    @theconformist

    It is complicated stuff. And for BM cameras as I understand reports it is worse compared to HDSLRs. Best idea is to use good IRND filters.

  • kholikholi

    It's worse than DSLRs, but not worse than other cinema cameras (RED, F35, ALEXA).

    You have to use the RIGHT IR cut, or the right IR NDs, or the right kind of ND in general.

    RED - Schneider Alexa - Tiffen F35 - Can't even remember.

  • vicharrisvicharris

    Yep, every camera responds different to each manufacture. P.I.T.A. But yes, these cameras do need better IRNDs indeed. I'm not one for stacking glass if I don't need to.

  • Vitaliy_KiselevVitaliy_Kiselev

    Yep, every camera responds different to each manufacture. P.I.T.A. But yes, these cameras do need better IRNDs indeed.

    It is not magic. Filters are described by spectral measurements. And something tells me that BM problem can be either with sensor or with filter before sensor. As making it proper requires skill and it seems like BM and/or sensor manufacturer can lack some of it.

  • azza_actazza_act

    @vicharris I see you sold your tiffens. If you didn't need the 2.1, would you still use the set? Are the rest of the IRNDs in that set still good for the bmcc?

  • kholikholi

    I don't understand your comment about "making it proper" but it's likely my fault:

    RED has IR issues if you aren't using the right IR ND combos Alexa has IR issues if you aren't using the right IR ND combos FS100 has IR Issues if you aren't using the right IR ND combos

    Canon's own internal IR NDs on the C100/300 aren't even perfect, they don't do as well as TrueNDs.

    This really isn't magic, the reality is that just buying some IR ND and expecting it to work for every camera has been pretty much unheard of up until recently.

  • Vitaliy_KiselevVitaliy_Kiselev

    This really isn't magic, the reality is that just buying some IR ND and expecting it to work for every camera has been pretty much unheard of up until recently.

    Thing I am talking about is that manufacturers need to specify their sensor parameters and their IR filter (if it is present). As both of them can affect performance of ND filter. Sensor and IR filter together define how light located outside visible spectrum affect sensor output.

    Another thing is that instead of mumbo jumbo shootouts it is required to make spectrum measurements of all ND filters so it'll be all simple and clear.

  • vicharrisvicharris

    @azza_act Well, if I had to I guess I would. It would just piss of the colorist :) Every filter is a little different and some are very different. You can see a comparison I did with the whole set. Don't want to post it here because it is a huge thread of files. Takes up a bit of room to keep posting the same thing all over the internet. Anyways, they aren't terrible but I would rather have a set that is pretty damn spot on all the way through and from what I've seen of the Hoyas, they seem like the safest bet for BM cameras. I've seen some decent stuff with nice faders and IR cuts but I shot with two cameras a lot ad it's actually cheaper to buy the one set and just be a stop off. Usually doesn't change the DOF too much for the director or DP to care with these cameras. Plus I just don't want to stack glass. My mentor always advised against it when it was absolutely needed.

  • kholikholi

    @Vitaliy_Kiselev

    Noone publishes this information. It's not like BMD is doing anything different. Camera manufacturers have always left that up to second party, this is no different.

    Or better yet, just tell filter designers to follow the lead of the very scarce few brands that deliver filters what work across the board for all cameras. There are only two.

  • Vitaliy_KiselevVitaliy_Kiselev

    Or better yet, just tell filter designers to follow the lead of the very scarce few brands that deliver filters what work across the board for all cameras. There are only two.

    I already said, I am against pinching brands and such. Better show spectrum measurements of this filter.

  • nomadnomad

    Well, I second your criticism, Vitaliy.

    But there's a lot manufacturers don't tell us these days. If they were publishing filter spectrums like Zeiss is still doing for MFT charts…

    And I'm afraid there's nobody on this board with a Minolta CS-2000. So, back to try and error.

  • Vitaliy_KiselevVitaliy_Kiselev

    And I'm afraid there's nobody on this board with a Minolta CS-2000. So, back to try and error.

    Why you need Minolta CS-2000?

    All you need is spectrophotometer with some IR and UV range margins, not big, in fact.

  • nomadnomad

    I actually tried with a cheaper spectrophotometer by X-Rite and it was not precise enough. I couldn't measure differences consistently that were clearly visible when trying filters both on Scarlet and BMPCC.

    Do you know of a model that works?

  • Vitaliy_KiselevVitaliy_Kiselev

    I actually tried with a cheaper spectrophotometer by X-Rite and it was not precise enough

    What model you used and with that software?

  • nomadnomad

    The i1Basic Pro 2 with the software i1Profiler. The problem with relatively cheap spectrophotometers is the low-light behavior. So, how to measure IRNDs?

  • Vitaliy_KiselevVitaliy_Kiselev

    Try to use http://www.argyllcms.com/ , they have enhanced resolution mode and spectrum data and/or plotting.

  • theconformisttheconformist

    Thank you all for the very helpful info!

  • azza_actazza_act

    @vicharris ok, thanks for the response, I'll have to look into the hoyas.

  • ADCfilmsADCfilms

    Hoya 77mm UV-IR Cut Screw In Glass Filter, on offer here if you're in the UK, only £54 http://www.microglobe.co.uk/hoya-77mm-uv-ir-cut-screw-in-glass-filter-p-9991.html

  • HallvallaHallvalla

    I bought the Hoya. Hopefully it's a good one for the BMPCC.

  • nomadnomad

    It works very well for me on the BMPCC.

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