dsiner wrote:
My son wants me to do some Christmas scene family pictures. I haven't done much in this area. I have been researching lenses. I would like some recommendations. I am shooting a Nikon D7200. From what i read the 85mm 1.4 lens seem to be popular for this type of work. I currently have, Nikon 18-55, 55-200 kit lenses, Tamron 16-300, Sigma 100-400 and a Nikon 35mm f1.8. These pictures will probably be done inside in a make shift studio with a couple backdrop scenes. I will be renting the lens.
You mention working indoors with a "makeshift studio" and "backdrops".
In all likelihood, you could use your 18-55mm lens.
For portraits of individuals with an APS-C camera, 50mm to 85mm are the two extremes of the "ideal range" or "traditional, short telephoto portrait focal length range".
HOWEVER, 85mm can be too long for indoors... if "studio" space is limited. It might be fine for a tight shot of a person's face, but in many rooms may be unable to frame a head and torso shot (let alone a group people and part of the background). So right off the bat I'd lean toward 50mm for indoor use.
NEXT, you are probably talking about a group portrait, since you mention "family pictures". Plus you will be wanting to incorporate some of the backdrop "scene". So you might need that 35mm or even 28mm or 24mm focal lengths that can be done with your kit lens.
FINALLY, the reason large aperture primes (such as f/1.4 or f/1.8) are popular for portraits is to be able to strongly blur down backgrounds in situations where you have little control over them, such as shooting candid portraits on location. However, when shooting in studio with a theme background, it's just the opposite... You don't need or even want a large aperture. You will need to stop down to f/5.6 or f/8 to render the background recognizably and presumably will have some control over lighting to be able to use the smaller aperture without having to push your ISO too high. (It can be any type of lighting, though you may be wise to set a Custom White Balance and/or shoot RAW files so white balance can most easily be adjusted, if needed.)
For all these reasons, your 18-55mm lens will probably work fine. The 35mm f/1.8 might serve if you have limited lighting, but you'll have to be careful that a large aperture doesn't render too little depth of field and cause the background to blur down too much. Do some test shots and look at them closely, then adjust as needed.
You'll also need to be careful about getting too close to your subjects with focal lengths such as 24mm, 28mm or even 35mm, 50mm. Shorter focal lengths used too close will cause perspective distortion of peoples' features... i.e., make their nose look big and their ears look small. It can be humorous... or disastrous, depending upon the effect you're trying to achieve!
Also keep people away from the edge of the image when using shorter focal lengths... an effect called anamorphic distortion can make their body parts look oddly mis-shapened. "Elephant legs", "Hellboy arm" and "Popeye arms" are all too possible, if you aren't careful! Again, might be fun if they have a good sense of humor.... or not if they don't want to look silly.