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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

What's the Darkest ND Hot-Mirror Combo Filter Made?

michael zaletel

michael zaletel

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For shooting at high noon on a bright sunny day at f/2.8 and 1/48 shutter speed, I've had to combine my ND1.2+Hot Mirror with my ND.6 to get a decent exposure. I imagine with the MX sensor, I'll need even greater ND right? Does anyone manufacture an ND1.8+Hot Mirror or greater? Or am I asking a uninformed question here? :)

-michael zaletel
 
We used some 4x5.6 tiffen here on an MX feature.
ND + hot mirror combined: 1.2, 1.5, 1.8, and 2.1.
This is a 7 stops loss, puting the sensor at 6 ISO if you rate your MX at 800 !
 
Nils J. Nesse said:
Formatt Hot Mirror ND goes to 2.4
http://www.formatt.co.uk/hd-glass-filters/hot-mirror/hd-glass-filters.aspx
Click to expand...

Thanks for the link Nils. Was trying to find that but couldn't. Wow $600 though. That AbelCine RED Formatt filters special comes out to like $200 each but only goes up to 1.2. Is it substantially better to use say a 2.1ND+Hot Mirror than to use a 1.2ND+Hot Mirror and a .9ND stacked. Any way to get the 2.4+HM for less than $600 as part of a similar package?

-michael zaletel
 
no hot mirror filters needed with red MX sensor and new olp glass

no hot mirror filters needed with red MX sensor and new olp glass

michael zaletel said:
For shooting at high noon on a bright sunny day at f/2.8 and 1/48 shutter speed, I've had to combine my ND1.2+Hot Mirror with my ND.6 to get a decent exposure. I imagine with the MX sensor, I'll need even greater ND right? Does anyone manufacture an ND1.8+Hot Mirror or greater? Or am I asking a uninformed question here? :)

-michael zaletel
Click to expand...

I understood that the MX upgrade with the new OLP glass:confused5: as well does not need IR blocking filters anymore??
 
On a recent feature I shot close to wide open and had ND's to wash away 6 or 7 stops. We always had a schneider IR filter at the front of the Matte box. An odd thing did happen to one camera. We would get IR contamination on specific black clothing. This only occured when we NDed 6 stops or greater and only occured between 11am and 1pm when the sun was at its highest. It only happened to 3 peices of back clothing. Only one camera would be effected Even with an IR filter at the front of the Matte box. So it will be interesting to see how the MX sensor reacts under an Australian Summer when so much light is washed away.

Torstein DyrtingACS
www.torstein.com.au
 
ND 1.2

ND 1.2

Torstein Dyrting said:
On a recent feature I shot close to wide open and had ND's to wash away 6 or 7 stops. We always had a schneider IR filter at the front of the Matte box. An odd thing did happen to one camera. We would get IR contamination on specific black clothing. This only occured when we NDed 6 stops or greater and only occured between 11am and 1pm when the sun was at its highest. It only happened to 3 peices of back clothing. Only one camera would be effected Even with an IR filter at the front of the Matte box. So it will be interesting to see how the MX sensor reacts under an Australian Summer when so much light is washed away.

Torstein DyrtingACS
www.torstein.com.au
Click to expand...

DoP's told me just a minut a go the don't need a IR filter up to ND 1.2 with the MX sensor. Wait till my camera is back from RED and will test it beyond ND 1.2 in combination with a pola filter. Somebody tested this before?
 
ND 1.2 is a good number to go off of. It still depends on the amount of IR in a scene though. Beyond 1.2, you will most likely want some form of IR control. This actually applies to most any digital camera, not just RED. The OLPF on the MX brings the camera more in line with how most every other CMOS camera handles IR.

I really don't think Abel has any more of the RED package deals for Formatt filters. Or at least they didn't have any available about 6 months ago and I kinda took it that they would not have that deal anymore. And yet, I still bought a set of 4x5.65 Formatt ND and IR+ND from them at a good price. Definitely give them a call.

For the RED, even with MX, I still recommend having a full set of ND filters along with a hot mirror and a couple combo ND+IRHM filters at 1.2 or darker. It's all just about options and what you can afford to put in your kit I guess. If you're on a budget, for the MX I would recommend the following kit as a minimum:

IR Hot-Mirror, ND0.3, ND0.6, ND0.9, ND1.2, IRND1.8

With that kit and a 2-stage mattebox, you can get to ND2.1 (7 stops) without IR protection and up to ND2.7 (9 stops) with IR protection. Most hot mirrors are about an ND 0.3 and they're good to have in the kit. If budget is tight, I would consider skipping the hot mirror in favor of an IRND1.5 or IRND2.0. A lot comes down to what and how you shoot. The kit above is pretty generic and will work for many, but not for everyone.

Polas are nice to have, but they do not play well with hot mirrors. You can't put anything in front of a hot mirror. And polas often create their own funky effects if they are not the first filter in line (furthest out from the camera). You have to test for your application.

Depending on the level of ND you need and how bad the IR is for a certain set-up, you may have to choose between using a pola or an IR filter. Many times you can correct the IR color casts out in post. Sometimes they're too severe and you can't without a massive re-coloring effort or even not at all.

As always, test, test, test!

IR transmission also differs with lens designs and types. My Cooke 18-100, which I no longer own, handled IR totally different than Zeiss standard or super speeds, as an example. It blocked a lot more IR on its own and when materials like black nylon would start to look pink in a high-IR situation through a Zeiss prime, this would not show in the Cooke. However, the Cooke had it's own share of IR issues. It showed what looked like severe chromatic aberration, but in the IR portion of the spectrum. In the beginning with RED, shooting outdoors, I was getting a lot of strange halos around objects and I couldn't tell if it was a REDCODE issue or something else, but it turned out to be one way IR pollution would present itself through that big zoom. I ended up buying a Tiffen 6" round IRND 1.2 filter for that lens. That was like a $750 filter. Ouch.
 
michael zaletel said:
I imagine with the MX sensor, I'll need even greater ND right?
Click to expand...

Not necessarily. The MX isn't more sensitive than the M. Just less shadow noise. You won't clip any earlier in sunlight than you did before.

It is handy to have high strength NDs around though if you need to stack other filters though (diffusion, or grad NDs, or FX).
 
Torstein Dyrting said:
On a recent feature I shot close to wide open and had ND's to wash away 6 or 7 stops. We always had a schneider IR filter at the front of the Matte box. [/url]
Click to expand...

All due respect, but was it round the right way? If you had the Tru Cut 750 facing the right way you should NEVER see IR pollution, even 7 stops down.
 
Cail Young said:
All due respect, but was it round the right way? If you had the Tru Cut 750 facing the right way you should NEVER see IR pollution, even 7 stops down.
Click to expand...

In my experiance with the the RED in Australia is that the 750 is very effective but alone wont completely shut out IR polution in all NDing situations. For me IR is not constant. I have seen it come depending on the time of day , weather conditions, what type clothes people have on and differing from camera to camera under constant conditions. Dont really on the 750 to remove all IR polution through all conditions. If you are looking for the best effective control of IR I would have a polariser, a full selection of ND filters without IR and a full selection of ND filters with IR built in and the 750 IR filter. This way you can tackle a situation for what it is at that moment for that camera. And of course it goes without saying that the IR has to be correctly positioned the right way around in the matte box.

Torstein Dyrting ACS
www.torstein.com.au
 
I have custom Tiffen's up to 1.8.
I prefer to use straight NDs and add a clear Hot Mirror as needed.
Cheers,
Harry
 
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