A few facts:
1. In a studio of modest dimensions, for example a studio with a maximum shooting distance of 20ft and similar width: the difference between using a 24mm lens or a 28mm lens renders that maximum shooting distance LESS by about 3ft.
2. A reduction of 3ft (about 1 metre) in the Shooting Distance can be quite significant, especially when the consideration of Subject to Background Distance enters the equation.
3. When one is shooting Portraits using an APS-C camera and is considering using F/4 maximum aperture lenses, Subject to Background Distance is a most relevant consideration for that shooting scenario.
4. The OP asked advice for a suitable lens to use for shooting portraiture in a studio in the Opening Post.
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On a tangent to this main theme of this thread, there has also been general advice given to all readers regarding the purchase of ‘crop only’ lenses and linked to that advice was the statement that ‘crop only’ lenses do not work on ‘FF’ cameras.
As has been pointed out the Nikon system having the availability for some of the Nikon Bodies to switch to using ‘crop lenses’.
But note: there is also the possibility to more widely use other ‘crop only’ lenses on other ‘FF’ bodies.
For one example: Canon ‘FF’ bodies can use Tamron; Tokina and Sigma ‘crop lenses’, but as already mentioned there will be some optical vignetting at some focal lengths.
In consideration of the fact of possible optical vignette it is important to clarify that these lenses will ‘work’ but with some limitations.
WW