Compromise colour temperature filter.

[ajuk]

I often use an 80b filter on my lens when I do night traffic trail photography and since I have started doing that I haven't looked back from the days when I didn't use a filter at night. but indoors at night I find an 80b blocks out too much light and for some reason there is no tungsten balanced fast negative film.
In fact why aren't films like Portra 800 and Superia 1600 tungsten balanced as if you need that speed in daylight, I thought Portra 800 was for taking pictures indoors at night, no?

Anyway I was thinking of going down a compromise root of using a less blue filter that makes less of a correction and lets more light in,do many people do this?
Anyway I am not sure what filter to get, What I am confused about is that according to this an 80d only reduces the speed by 1/3 of a stop but increases the temperature by 1,300k but an 82b only increases the temperature by 300k but reduces the speed by 2/3 of a stop?

 

[ajuk]

Anybody?

 

[nickandre]

I ask the same questions. Portra 100T was discontinued because not enough people used it to make it viable. I don't really know why Superia 1600 isn't tungsten balanced. I can't imagine using that in daylight for anything but special effects. For that a 85B filter would work fine.

The 80A daylight to tungsten light converter uses more light because there is a relatively low amount of red light in daylight, so much of the other two has to be removed to get you to your proper color balance. It's 1 and 1/3 stops for a 80A or B I can't remember and 2/3 for an 85B. Supposedly the job of the 85B is easier.

 

[ajuk]

Yeah I know with an 82b there will be less of a correction, but If its still out but not by as much that's ok. But what I am confused about is the 80d seemingly making much more of a correction for the same amount of light loss as an 82b.