I couldn't use my logitech C170 webcam in cheese. I think this is a common issue with cheese, the terminal ouput shows this:
libv4l2: error got 4 consecutive frame decode errors, last error: v4l-convert: libjpeg error: End Of Image
(cheese:9695): cheese-WARNING **: Failed to allocate a buffer: gstv4l2src.c(871): gst_v4l2src_create (): /GstCameraBin:camerabin/GstWrapperCameraBinSrc:camera_source/GstBin:bin35/GstV4l2Src:v4l2src1
I don't think this is a Solus problem really, this is an old bug, but the workaround is very simple: change the resolution to 640x480. So maybe something can be done to fix this in Solus, maybe some sane default that can be used to avoid this annoyance...