Edit - I think this might be easier to read now: abit anyway: Well I was interested in testing out teleconerters vs extension tubes - as well as finding out what happens when you put the two together - so armed with my kit I setup the following test: Kit used: Canon 400D Sigma 150mm f2.8 macro Set of Kenko teleconverters Sigma 1.4 and 2 teleconerters Manfrotto 055XPROB tripod Manfrotto 322RC2 head Manfrotto focusing rail remote release for canon 400D Speedlite 580M2 + Lumiquest softbox Hoodman anglefinder cable off camera flash cord one coin one torch The setup - tripod setup with focusing rail attached to tripod head (322RC2). Lens, 150mm f2.8 macro, was then attached via its tripod collar to the focusing rail - the lens was also twisted in the collar so that all shots would come out in the portate orientation - this is due to the fact that a 400D with grip will not attach to a 150mm whilst on the focusing rail (the grip hits the edge of the rail). This problem is overcome by using something like a 1.4TC or extension tube - but since this was a test all shots were taken in the same orientation. Because of the orientation the flash was taken offcamera via the cord and was held in a position roughly normal for a hotshoe mount - I was going for basic lighting nothing fancy. Camera was then set to take shots with the following settings: f16, ISO 200, 1/200sec - flash set to ETTL and metered with preflash test shot before each shot was taken. Mirrior lockup was also set in the camera and the remote used to triggor the shutter to minimise shake in the shots. With the kit setup the torch was used to aid in focusing - the torch removed during the process of taking each shot when light would be provided by the flash (torch needed because my room is dim). Once the shots were taken the images were uploaded to the computer and the RAW files were convertered to JPEGs - the only editing which took place was white balance adjusting which was set to a custom value and was kept the same for all the shots - no other editing has been done to the shots - please also note that these are RAW shots coverted to JPEG and so will look softer than ideal (he defends himself ). Also note that the heal tool was used to remove dustspots in the shots - an interesting thing to note is that as magnification increases the dustspots become an increasing problem - - I think I got most of them . Note that for each shot below a link is provided to the fullsized image on filckr and I would be interested in peoples opinions of the results. so the shots:: Sigma 150mm f2.8 macro only / Sigma 150mm and 1.4 teleconverter / Sigma 150mm f2.8 macro only http://farm4.static.flickr.com/3371/3256899516_045e6cc1b0_o.jpg Sigma 150mm and 1.4 teleconverter http://farm4.static.flickr.com/3257/3256074137_96c240430f_o.jpg Sigma 150mm and 2 teleconverter http://farm4.static.flickr.com/3430/3256909514_66fef9dce9_o.jpg Sigma 150mm and 1.4 and 2 teleconverters http://farm4.static.flickr.com/3314/3256938448_42d5ce242a_o.jpg Sigma 150mm and 12mm extension tube / Sigma 150mm and 20mm extension tube / Sigma 150mm and 36mm extension tube Sigma 150mm and 12mm extension tube http://farm4.static.flickr.com/3105/3256914086_e55ee8372b_o.jpg Sigma 150mm and 20mm extension tube http://farm4.static.flickr.com/3427/3256918778_fbab04179f_o.jpg Sigma 150mm and 36mm extension tube http://farm4.static.flickr.com/3363/3256093737_c4a1cf3218_o.jpg Sigma 150mm and 36+20mm extension tubes http://farm4.static.flickr.com/3300/3256098511_ef5eeda517_o.jpg Sigma 150mm and 36+20+12mm extension tubes http://farm4.static.flickr.com/3459/3256933266_f52d336fc6_o.jpg Sigma 150mm and 36+20+12mm extension tubes and 1.4 + 2 teleconverters (everything ) http://farm4.static.flickr.com/3430/3256944068_0f26400a75_o.jpg What follows now is a comparison of using the 1.4 teleconverter along with each of the extension tubes. Also I tested putting the kit in different orders for each combination - order is from camera; Sigma 150mm, 1.4 teleconverter and 12mm extension tube / Sigma 150mm, 12mm extension tube and 1.4 teleconverter Sigma 150mm, 1.4 teleconverter and 12mm extension tube http://farm4.static.flickr.com/3414/3256948552_3b928b061e_o.jpg Sigma 150mm, 12mm extension tube and 1.4 teleconverter http://farm4.static.flickr.com/3317/3256963762_1e482e9bc3_o.jpg Sigma 150mm, 1.4 teleconverter and 20mm extension tube / Sigma 150mm, 20mm extension tube and 1.4 teleconverter Sigma 150mm, 1.4 teleconverter and 20mm extension tube http://farm4.static.flickr.com/3123/3256953178_625c98d9c1_o.jpg Sigma 150mm, 20mm extension tube and 1.4 teleconverter http://farm4.static.flickr.com/3462/3256139725_c5d86345c7_o.jpg Sigma 150mm, 1.4 teleconverter and 36mm extension tube / Sigma 150mm, 36mm extension tube and 1.4 teleconverter Sigma 150mm, 1.4 teleconverter and 36mm extension tube http://farm4.static.flickr.com/3078/3256128623_c5f56bf4ea_o.jpg Sigma 150mm, 36mm extension tube and 1.4 teleconverter http://farm4.static.flickr.com/3477/3256144901_b8f405eb05_o.jpg And we are done - now someone tell me what this all means! :lmao: seriously please someone!