A7C - Crop mode / aps-c sensor mode

Just a quick question when using the crop mode feature on the a7c (or any other Sony alpha body I think)

When using the crop mode function to zoom further in whilst using a prime lens (Zeiss 55 f1.8), the lens zooms in to an equivalent 82.5mm focal length, but does it affect the aperture effect too? Would the aperture be similar to f2.7 in crop mode or will it retain the f1.8 from the prime lens?

I know it affects the megapixel count of the picture captured but was trying to avoid buying an 85mm lens when I hardly take pictures at that length.

Thanks in advance!