Hot Mirror Question

[Justin Marx]

If I use a hot mirror, let's say hot mirror N9, can I add my standard N6 and be ok?

Thank you!

 

[Justin Marx]

Anyone?

 

[Russ Campbell]

Watch out for ghosting. I've never had much luck adding any further ND's together with my Pancro IR+ND's. Look closely at the highlights in 1:1 magnification as this is usually where the ghosting is most visible. Hope this helps.

 

[Adam Bricker]

Yes, I was taught that you can add additional NDs. The Hot Mirror should be the front facing filter (with hot side out) and the additional NDs should be behind the Hot Mirror.

 

[Jon Carr]

Watch out for ghosting. I've never had much luck adding any further ND's together with my Pancro IR+ND's. Look closely at the highlights in 1:1 magnification as this is usually where the ghosting is most visible. Hope this helps.

I get ghosting with my Panchros IR+ND all the time I stack. I guess Panchros shouldn't make the hot mirror on both sides.

 

[ericyoung]

Panchros are apparently known for ghosting when used with Red cameras, but other makes seem to be OK with being stacked as long as the hot mirror is the one at the front furthest away from the camera. Of course any multiple glass air interfaces can cause flare and reflections, so it's still something to watch out for with other makes.

 

[Abiodun Shote]

Maybe you can PM Phil Holland. I think he's conversant with HMs

 

[Phil Holland]

If I use a hot mirror, let's say hot mirror N9, can I add my standard N6 and be ok?

Yep. You can stack normal NDs behind your Hot Mirror/ND combo filter. Like others mentioned ghosting can happen. You'll also notice visual resolution loss at longer focal lengths. Past 85mm essentially.

I recommend to use either Formatt Hot Mirror/ND Combo filters or the Tiffen IRND/Hot Mirror combo filters on Epic and Scarlet with Mysterium-X sensors based on the most recent tests done. Both provide good results. I have to say the Tiffen 1.8 looked better than the Formatt.

Less filtration is usually a good idea on these higher resolution bodies. Avoid vari-NDs.

 

[Brian Dougherty(PANCRO)]

Yes Ghosting can be problem if you try to stack any kind of ND's behind a combo IRND or hot mirror. Also Flags and other methods are a good idea.
We have many many clients who are pleased and experiencing marked success w/red using our filters.
There are many variables when it comes to this issue.
I belive the key is being aware that combo filters both absorb AND reflect. Proper technique is essential and well worth it because of our ir blocking and ultimate color nuetrality that comes with a non dicroic filter (Pancro). You will pay for it in post if you use an IRND solution that isn't neutral and has inferior IR blocking. Trust me

 

[Brian Dougherty(PANCRO)]

FYI-One of our clients in scotland: from his site

IRND Filters and Others:

Probably, the most important set of filters required is a good range of Neutral Density filters, preferably with built-in Infra-Red features to avoid mattebox stacking and filter reflections. Tests clearly show that as you apply ND filters over 0.6 they have the effect of a magenta tint which in turn causes blacks to look red / brown. At ND 1.8 the IR contamination is horrendous. If this contamination is not corrected at the camera, you will have a hard time in post production and you will regret it. After much research I leaned towards a set of Schneider Platinum Series IRND’s (they do add a slight green tint which is much easier to correct than magenta), however, after months on a waiting list (manufacturing issues?), in desperation I decided on a set of Pancro Hot Mirror IRND’s. I initially avoided these filters due to some complaints regarding ghosting/reflection issues. However, to date we have not experienced any problems and are very happy with them. One thing I will say about the Pancro’s, there is no colour shift whatsoever when using them. Other popular manufacturers are Tiffen, Formatt and Rosco, every filter set has its pros and cons.