My question is what is the magnification if I stack these together? I have a 12mm extension tube between them. Will it take my 200mm to 680mm or 560mm. Just wondering.
well this is two 2x canon mkiii teleconverters stacked with the 12mm tube, also 47mm of extension tube added to a sigma 100-400mm @ 100mm, the camera is the M50 with a crop of 1.6x the image is of 2mm of ruler on the sensor, uncropped i'm not 100% sure but i think i worker it out to 17x macro magnification, one thing i will say though, i only trust canon official extension tubes and adapters for crazy ass stuff like this, i had a Neewer brand extension tube tear itself apart on this setup so dont trust off brand stuff when stuff gets heavy there is alot of light loss with the stacked x2 converters, i had to use 2 snap-on led work lights just to get enough light, on the + side the auto focus still worked!! though it was really slow at that mag. i do want to try it on the moon at some point but i'm going to build a long bed mount to keep everything rigid, the settlement creep when you touch the set up was mad, ended up using a remote trigger and moved the ruler rather than the lens for focus i since have gotten a "kenko tele plus 3x" teleconverter for ef mount, interestingly this converter doesnt have any lens protrusions past the body of the converter so you can use them on the types of lenses with the rear elements right at the back of a lens. imagine staking 2, 3x converters
