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View Full Version : Dragon + Motion Mount + Tiffen IRND, Blue = Purple???



Adam Howden
07-30-2014, 03:27 PM
Hi All,

I was shooting a little Sharp TV spot the other day and noticed some weird colour business in the blue violet spectrum. Can anyone shed any light on what I'm seeing here?

The beanie, the flag, hat and scarves were all the same or basically same colour blue, a royal or navy blue. But in the image that colour was showing up as a quite vibrant almost violet or purple?

The combination was Dragon Sensor - Motion Mount (Soft shutter @ probably around 0.9-1.2 ND) - a stiffen IRND about a 0.6 ND, shot with Arri Ultra Primes.

Is this IR contamination or is it the other end Ultra Violet contamination? I'm shooting a Jeans spot next week and a little worried my blue jeans are going to be purple? help....

https://www.flickr.com/photos/90728835@N06/14766744276/

Daniel Doherty
07-30-2014, 03:36 PM
The extra IRND could be wreaking havoc. IIRC, the motion mount already has an IR built in so it has been recommended you use standard ND's.

Phil Holland
07-30-2014, 03:50 PM
@Adam. The Motion Mount and Dragon itself cut IR. You really don't need to use anything but regular ND filters.

For instance here's ND 2.7 on both OLPFs:

http://www.artbyphil.com/phfx/photography/redEpicDragon_Kozmo/bigs/phfx_redDragon_NewOLPF_ChartDaylight.jpg

Adam Howden
07-30-2014, 04:05 PM
Hey Guys,

Thanks for your response. Ok cool, I understand.

Phil - So those two examples are with a straight ND2.7, with the only IR cut coming from the OLPF?

So what I'm seeing with the Blue - Violet... Is it possible that there's just been too much IR cut and has resulted in a pushed blue, or to put it another way. I've robbed the blue of any red and therefore it's just gone a little violet bananas??.

Phil Holland
07-30-2014, 04:57 PM
Hey Guys,

Thanks for your response. Ok cool, I understand.

Phil - So those two examples are with a straight ND2.7, with the only IR cut coming from the OLPF?

So what I'm seeing with the Blue - Violet... Is it possible that there's just been too much IR cut and has resulted in a pushed blue, or to put it another way. I've robbed the blue of any red and therefore it's just gone a little violet bananas??.

The examples show regular ND in sort of an extreme ND situation at ND 2.7. They are simply white balanced to the chart and there's no purple in the fabric, which is good. You can also see the improvement of the new Dragon OLPF over the orginal OLPF as well.

Long and the short of it:

Dragon: Has IR cutting built in and is designed not to need additional IR filtration.

Motion Mount: Also has IR cutting built in. Works in tandem with Dragon and works well on Mysterium-X.

This means you don't need IRNDs, IRND/Hot Mirror Combo Filters, or Hot Mirrors in general with Dragon.

The possibility of slight color shifts are high when utilizing additional IR filtration like the Tiffen IRND/Hot Mirror Combos.

Adam Howden
07-30-2014, 06:13 PM
Thanks Phil,

Really appreciate you clarifying and your input here.

Thanks a lot!

Nick Morrison
07-30-2014, 06:18 PM
Thanks Phil,

Really appreciate you clarifying and your input here.

Thanks a lot!

Phil never ceases to amaze...an invaluable resource!!