Yes, it's because you shot under incandescent light. All slide film manufactured these days is daylight balanced. The average sunny day in bright sun or hazy sun has a color temperature around 5,000 K. The tungsten balanced slide films manufactured in the past were set up for a color temperature of around 3,200 K. An 80A filter will absorb 2 stops of light but will allow you to shoot daylight balanced slide film under 3,200 K lamps. With the fastest currently manufactured slide film on the market being ISO 100, it's going to be like shooting indoors at ISO 25!
Here's the big caveat: Most incandescent lighting found in homes is not 3,200 K, it's 2,700 K, which is shifted even more blue deficient, so even with an 80A filter, your picture will still look pretty yellow.
If you're going to shoot slide film indoors, you've got two options until somebody (FILM Ferrania comes to mind) comes out with a faster film:
- Use flash if you want to hand-hold. ISO 100 is too slow for hand-holding indoors without flash, in my experience.
- Relight the scene (but you're gonna have to use a tripod because ISO 100 is too slow for hand-holding indoors). You can get LED bulbs that are daylight balanced and shoot under those.
I've had good experience with option #2 above with Kodak Portra 400 (pushed 3 stops, or not pushed and shot at least 2 stops underexposed (IMHO the shots that weren't pushed look a bit better, though shadow detail is missing), which is a daylight balanced color negative film. YMMV with slide film, but the scans from the Portra look pretty darn good. I'm gonna go for the Portra 800 this Christmas under the 5,000 K LED bulbs for available light, and also shoot some Agfaphoto Precisa CT 100 and Provia 100F with flash.
