Sunset. Filtered photograph of a sunset with clouds. There are cirrocumulus clouds at top, cumulus clouds at centre and dark grey stratocumulus clouds obscuring the sun at lower centre. Cirriform (cirrus) clouds are made of ice crystals which gives them their fibrous appearance, they are found above metres or 20,000 feet. Stratiform clouds (altostratus) are also comprised of water vapour and have a layered appearance, they are seen below 2000 metres or 5000 feet.