Formatt Hot Mirror Color Cast

[Tripp Green]

I just got a Formatt Hot Mirror ND 1.5 and was surprised at the extreme color cast present. The filter is a 77mm screw-on. I attached a jpg of this, and was wondering if maybe I'm doing something wrong here, the other shots I've seen on the forum using Formatt haven't had nearly the Blue/cyan cast I'm seeing. I'm thinking about giving the Tiffen IRND a go now. Thanks in advance!

 

[Gunleik Groven]

well, ND 1.5 is pretty heavy on your images.
But I'd have guessed you could WB that out...

 

[Tripp Green]

I can WB it out, it's just like 8000K. So is this normal then?

 

[Phil Holland]

Seems heavier than my 1.8. I'd shoot a grey card with and without and see if they balance.

 

[Tripp Green]

I was actually specifically referencing your tests in my first post Phil, the uncorrected stills you posted in another thread (I can't seem to find it now) didn't seem to be so far off before WB. Thanks for the advice!

 

[Phil Holland]

Here you go. This is the 1.8 77mm. They have a bit of a cast, but it's not that much.

I no longer have a 1.5 to do a quick test for you as my entire set of 4x5.65s were stolen last week. Which feels wonderful.

 

[Tripp Green]

Sorry to hear about your filters Those are exactly the stills I remembered. Definitely less that what I'm experiencing. Strange. Thanks again!

 

[Trevor Meeks]

Why not just correct for this with the green/magenta adjustment slider in RED CINE-X or the in-camera green/magenta settings?

 

[Brant Hadfield]

I just rented a 4x5.65 Formatt Hot Mirror ND15. I have not tested it yet. I gather the correct polarity is purple mirror side facing out? And I am guessing you've checked that as well?

 

[Tripp Green]

I can, that's why I was wondering if it was an issue or normal. Maybe because I'm not accustomed to RAW workflow (And ND this heavy), I guess I was just expecting the image at normal daylight WB not to be so affected.

 

[Mark Toia]

Happens to all digital cameras as well.

I've found that some IR filters work better than others as well.
YOu can set a look in RCX that can get rid of that look quite easily...


Shooting film for years I used to see the same problem when loading up the filters... I would always blamed the lens, processing, the film. Only shooting digitally made me aware that it's a problem from using to many filters. Weird how the digital age really makes issues so much more apparent.

 

[Jeff Kilgroe]

This is normal and happens with any camera, especially digital, but can also present itself with film. With heavy ND, it's not so much a color cast, but a flux in color temperature for various reasons ranging from filter formulation to your environment.

When it comes to filters in front of the lens, less is always more, IMO. Of course, when you need heavy ND, you just need it. Best to not stack ND filters when you can avoid it, never put more than two and never use more than one IR at a time.