def METHOD_NAME(pacton, file, center_wavelength = 0, show_ = True):
	data_group = file.require_group("zero_wavelength_images")
	img = pacton.get_image(center_wavelength,debug=0)
	exptime = pacton.pixis.GetExposureTime()
	attrs = {"exposure_time":exptime,"center_wavelength":center_wavelength}
	data_group.create_dataset("image_%d",data=img, attrs = attrs)
	data_group.file.flush()
	if show_ == True:
		#exercise: put in if statement, only run when suitable flag (ie. input parameter is set to true)
		fig, ax = plt.subplots(1)
		ax.imshow(img, cmap='gray')
		plt.show()