C-41 portrait tips for the beginner? (Mostly lighting and metering)

My background: mostly B&W landscapes, contact printing on traditional B&W paper or alternative processes.

This Thanksgiving, we're hosting and getting together a few family members that we don't see that often, and my wife wants some pictures (besides the typical digicam), so I bought some Kodak Portra 160 (and Ektar 100 as well, but probably will only use that for landscapes) in 4x5.

I have taken a couple of outdoor portraits with my 8x10 in the summer in B&W, but I haven't shot a single piece of color film in LF ever, and only a tiny bit of slide film in MF. I don't own any flash units or anything like that, so I'll have to rely on shooting either outside or relying on a mix of incandescent and fluorescent lighting inside the house.

Are there any tricks I need to know about Portra? Or, should I just basically meter and shoot like I normally would with B&W?

If I have to shoot indoors, do I need any filters to correct for colors? I could probably take pictures inside with either all incandescent or all fluorescent lighting depending on the room, rather than having to worry about a mix. I really only have B&W contrast filters and an 81A, so if I do need some kind of color conversion filter, I'm probably out of luck unless I can find something locally. Or do you think it would be better to shoot outside instead? I think the weather will cooperate enough for family members who arrive earlier in the day.

Processing the film will be done by a reputable lab (I'm not set up for color darkroom work), so I'm not so worried about what happens after the shot, I just want to get the color exposures as best as I can. I will be taking B&W pics as well, just to be safe.

Yes, I know I should have tested this earlier, and will rely more on the B&W work for keepers, but I hope to get a little lucky with color, that's all.

I don't see how you could have enough ambient interior light to do any sort of large format group portrait with ISO 400 film, much less ISO 100. So take them outside earlier in the day and find some nice open shade or hope for an overcast day.

Then just shoot it like it is B&W.

Pay attention to where you focus and depth of field, because once you add a second person to the mix you have to have two separate places sharp. If someone stands in front of another, you need a couple of feet of depth of field and you are only getting that from stopping down into the middle f-stops. But amateur subjects often fidget and keeping them in a zone of focus, or even steady below 1/30th is challenging, so that is why many people prefer Portra 400.

Scout the spot ahead of time, do some meter readings, even do a test set up w B&W.

If you do want to get into lighting and shooting indoors, learn how to use a digital camera to proof your lighting. Fuji Instant film helps too. But you realistically need more lighting horsepower and some passing experience at managing it before you can expect successful results.

Thanks Frank, that's kind of what I figured. I will probably be doing some groups of 2, do you think that might work or should I just go for outside? I've dealt with that before, trying to get two faces lined up in the focus plane.

Definitely outside, unless the house has a large, light-filled room that gives you f22 at 1/30s.
Give people a quick run-down of LF camera procedure, so they help you make good shots; let them know the pace is different than with a digital or SLR.
Shooting a couple of sheets of B&W as a back-up is a good idea.
Filtration is taken care of in PS.
I agree with Frank, treat colour as you would B&W.

I'll risk shooting individuals at 1/60th @ f/5.6 but most homes are not that bright on their own, unless you pose looking out of a window or something like that.

With two side by side people I'd want at least f/11 if they were very careful, but f/16-22 is a lot safer.

Once you get into stacked groups, you often do better dropping down to a smaller format camera and still shooting at f/16-22. Or move back to buy yourself a little more depth, and/or blast them @ f/32-45. Always do a practice with some assistants standing at the corners and figure out the posing. Don't forget that sometimes you can use movements, like the giant panoramic banquet shots done from high up, with front tilt, and a megaton of flash.

Wonderful, thank you very much for the advice.

If you have a family event and you want to make a picture that will be good, I would do something that you know how to do. If you shoot digital, I'd do it with that. At least as a backup.

I really think you should make your mistakes with portra on something you don't really care about. Shooting portra indoors is pretty much going to look like shit. Unless you really know what you are doing. Which takes time.

So: shoot some digital, practice on portra.