Ir + lens + 2x extender question - please help

[Flo Eckhardt]

Hallo!

I have been reading a lot about red one and IR problems when stopping down with NDs. I am using a Zeiss 10-100 zoom lens on a red mx using maximum of ND 9. As I am mostly shooting outdoors in snowy environment there is lots of light so with my set up I am always around T16. I also got this 2x extender for my lens what takes away two stops - so here is the question : does the 2x extender take away IR so I could use ND 9 with it or should I use maximum ND 3 with the extender as this takes already 2 stops of light going to the sensor.

Is there a difference in IR rules when using different lenses? or in my case more glass between the sun and the sensor?

Does anybody know where to get 4x4 IR NDs?

Thank you for your help and thoughts!

 

[Gunleik Groven]

As opposed to IR filters, the extender and iris cuts all light. <thus at higher stops, less need for IR filtering.

Also, remember that IR is not always a problem and when it is, you'll easily spot it. There's no point in running around with IR filters at all time, it only contaminate the signal-chain (when not needed).

Personally I have come to hate the IR + ND filter combo, basically because they are not stackable. I much prefer regular ND's with an IR cut in front, when needed.

(Which it most of the time isn't).

 

[Flo Eckhardt]

As opposed to IR filters, the extender and iris cuts all light. <thus at higher stops, less need for IR filtering.

Also, remember that IR is not always a problem and when it is, you'll easily spot it. There's no point in running around with IR filters at all time, it only contaminate the signal-chain (when not needed).

Personally I have come to hate the IR + ND filter combo, basically because they are not stackable. I much prefer regular ND's with an IR cut in front, when needed.

(Which it most of the time isn't).

Thank you for your reply. I never run into any IR problems so I don´t really know how to spot them on a run and gun production style of shooting - any ideas?

 

[Gunleik Groven]

Black goes purple, green goes muddy...

 

[Flo Eckhardt]

Black goes purple, green goes muddy...

thank you for your help! Most of my scenes are 2/3 snow covered mountains and 1/3 blue sky. Just small black or green areas so probably hard to detect in evf. I bring my gear in a black backpack so if i take a close up it should get purple so IR pollution could happen to my scene? It´s sunny outside so I think I just give it a try to turn black into purple

 

[Flo Eckhardt]

thank you for your help! Most of my scenes are 2/3 snow covered mountains and 1/3 blue sky. Just small black or green areas so probably hard to detect in evf. I bring my gear in a black backpack so if i take a close up it should get purple so IR pollution could happen to my scene? It´s sunny outside so I think I just give it a try to turn black into purple

OK - I was out there ... about 1000m above see level and almost perfect blue sky. I was trying with the 2x extender + ND 12 but the black backpack didn´t turn purple. ND 12 is all my ND power combined so I will try again when I got more NDs.

 

[Rob Ruffo]

IR is much worse in heat and rarely seen in cold conditions. IR is rarely a problem with MX sensors, and was much more troublesome with the old Mysterium 1