Good afternoon gentlemen. I have recently bought an IR film (the Efke one) to give it a try before this product disappears. My intention is not to get "special effects" but to penetrate the fog of distant landscapes. I understand that a dark red filter is not enough to actually have a proper IR anti-fog effect. However, I fear that a full IR filter would be too dark to be used with a reflex camera. What type/number of filter can I use to get a good anti-fog effect, with still enough vision left in the finder to be able to frame and focus the image correctly?