I don't know IR film but I'm interesred to try. I want to know if it is necessary to load in darkness. So, how to load film in a MF camera (Fuji GW690II) if I can't see the red dot. Is a dim light OK?
You do not need to load IR in total darkness. Just don't load it in direct sunlight, especially if you have an old roll of Kodak HIE...which I doubt. The IR films available today are barely sensitive to IR spectrum, such as Rollei, and Ilford SFX. No Worries.
I've loaded in shade with no problems (sometimes using my body for the shade). If loading indoors I don't even worry about shading it.
If it's your first time, I suggest putting the camera on a tripod and bracketing a roll to see what EI works for you.
Here is a thread from when I tried in 35mm:
(there was a url link here which no longer exists)
I have more recent MF examples, but, umm... cannot post them on the internet, lol.
After shooting many, many rolls of 120 format infrared film I'm convinced that loading a camera in the shade, even in my own shadow, is perfectly ok. The really critical time is in unloading the camera. If the camera doesn't take up the exposed film and backing paper tightly, causing the "soft roll" phenomenon, then the roll is not absolutely light-tight and edge fogging will happen. I have a Seagull 4A103A twin lens reflex camera that does exactly this.
You do not need total darkness to load IR film. Dim light, subdued light or shade will work. The dimmer the better. You also need a red filter such as a #25 or #29.