It was just a thought and Oh yes indeed - they are heavy - but are nevertheless pretty popular over here amongst the wild life folk - being versatile and providing very good results. I use the BIGMA personally and find little difficulty with the weight (but then I am a large lad) using it hand held at full extension and hardly ever a tripod (the latter being too cumbersome to carry if that makes any sense!!!). Also the range of long lenses that we have to choose from is limited (particularly for Sony) with virtually no Minolta available any more. I have the 70 - 300 that I use when weight is a REAL issue but this is seldom.