Optics Question: Object Distance with a Slit and Lens

[Oerg]

Homework Statement

If I have a light source and a lens then I would take the object distance to be the distance between the center of the lens and the light source. But if I were to place a slit between the light source and the lens, would the object distance now be the distance between the slit and the center of the lens?

I think the object distance would change as the light diffracts out from the slit.

 

[Redbelly98]

But if I were to place a slit between the light source and the lens, would the object distance now be the distance between the slit and the center of the lens?

Yes; the slit may be considered to be a light source in that situation.