I recently bought the Kenko Extension tube set ( 10 mm and 16 mm ) and used them on the Sony e18-200mm zoom lens for both normal close-ups and copying old slides. The light source for the tranny copying was a LP-100 Medalight light panel. The Nex 7 is on a copy stand and the 18-200 lens complete with lens hood and kenko tubes. By good fortune the lens hood resting on the slide holder matched up to almost a 100% copy of the original slide. Shame there isn't a focal length lock on the lens. Could do with more stickability when held down! The results were certainly more promising thn some tranny scans I did with a Canon9000f . Howver I did notice that edge sharpness was marginally better using my original method using a Nikon PB4 Bellows and Nkon 85mm lens with the Nex 7. Must do some more tests.

Utah 2002 Fuji 100
original copy raw f11 1/2sec 100 iso

100% crop Sony 18-200 Kenko tubes

St Lucia Kodachrome 64 1/3 f11 100 iso

121mm 1/30 f22 800 iso Nikon flash sb800

184mm 1/30 f32 800 iso Nikon flash sb800

300mm 1/125 f22 800 iso Nikon flash sb800

300mm 1/125 f22 800 iso Nikon flash sb800

Below are some early images taken in the garden using the extension tubes with the 18-200 mm zoom. Some have been shot using a Nikon SB 800 attached with a bar to the camera. Certainly on one day when there was a strong breeze this was a great help in freezing the image.