IR nd filters .... A few questions
Posted 08 May 2015 - 04:55 PM
2. With tiffen filters how do you use the non nd stand alone hot mirror filter. Is it effective to get standard nd filters and just place the hot mirror infront of them ? What strengths of ir nd work best with the hot mirror or does it work in such a way that it doesn't matter?
3. Does anyone use Schneider platinums with the red mx sensor and what do they think? I have seen tests and the footage that comes back looks super green I feel it must be losing Atleast some color information no?
Is there an overall preference between
Schneider platinums, tiffen hot mirror nds, and tiffen standard ir nds?
Thanks for any insight, I know there are a lot of topics about these filters and no clear answers it seems.
Posted 08 May 2015 - 05:18 PM
And can you stack IR ND's or are you only supposed to use one IR ND and then standard NDs under that?
Posted 08 May 2015 - 05:28 PM
Which to use depends on the specific sensor design. Red MX sensors pretty much only work with Hot Mirrors. I think things have changed with the new Skin Tone OLPF for Dragon. Arri and Sony require IRNDs but if you are using the internal NDs on the cameras which already have IR built in, then you can probably get away with straight NDs up to about N6.
Finally, there are two new brands of ND filters which seem to eliminate the need for IR or Hot Mirrors. Mitomo True NDs and Formatt Firecrest NDs are very neutral straight ND sets which (from what I understand) use metal particles imbedded in the glass to reflect or absorb the IR instead of using a special coating. I have not seen the Firecrest yet, but the Mitomos work very well on Sony, Arri, and Red without a color shift. Presumably they work great on film as well, Greg Irwin could tell you for sure. So everyone is switching over to those now. They are twice as expensive though.
Posted 08 May 2015 - 05:34 PM
You can't stack Hot Mirrors because their reflecting qualities would cause multiple reflections. With a filter pack, you should always place the Hot Mirror in the furthest tray away from the lens for this reason. One of the big downsides of Hot Mirrors.
Posted 09 May 2015 - 12:28 PM
thanks much. the Firecrests look great from the reviews and very affordable. True ND's seem like the ones to really use but yes expensive.
look forward to the day all cameras have internal ND or a better way of dealing with this!
Posted 27 May 2015 - 12:09 PM
Hey Satuski I have a production about to start and the rental house only has Tiffen IRND's and they are pushing it on me. I'm curious what your experience was that resulted in you saying that "IRND's pretty much dont work with the red mx"
Posted 27 May 2015 - 05:52 PM
This is a non-issue on the Dragon sensor since the new Skin Tone OLPF (have not tested Low Light) does such a good job of filtering out IR on it's own. We used IRNDs on a Skin Tone OLPF Dragon this week on a commercial and it was a little green but otherwise fine. Obviously, TrueNDs or Firecrests would have been ideal but they are not too many sets up in SF yet. We were shooting wide open on Summicrons day and night.
Posted 28 May 2015 - 10:11 AM
thanks much for the information, it's a new relationship and the situation is a little weird because of how the production has gone about things. Hopefully should work out today. Nothing worse then a rental house that won't just admit they don't have the right stuff they told the producer "Yea we have the best filters, nothing better then Tiffens" haha.
I'm in a 2 stage box and shooting 1/8 pro mist so I can't toss anything else in there and would really like to not anyways even if I had the space. Hopefully can get them to sub rent some hot mirrors.
yea wide open in the day is tough! I had ND 2.1 on the last thing. luckily we had hot mirrors. I bet those lecia's were looking good though