Hi Ardy,
I have used both the 1.4 and 2X tele converters extensively over several years and have the following observations. The 50 macro X 1.4 tele converter is my number one macro setup. The extra distance the 2X tele converter puts between the lens and the subject is what makes it useful. Some animals are to shy for the 50 X 1.4 combo but will not flee from the aditional distance provided by the 2X tele. The 2X tele reduces depth of field over the 50 or 50 + 1.4 combo. If a +5 to +10 diopter is added to the mix the distance provided by the 2 X tele can make the shot. With all lenses the more glass you add the softer the shot will become so the 2 X tele with a +10 diopter is going to fall off a bit V. the 50 macro alone. The larger tele converter adds the greatest magnifaction, 50 mm 1:2, 50 + 1.4+ 1:1.4, 50 + 2 X = 1:1 (in 35mm terms 1:1, 1.4:1, 2:1) appox.
I use the 2 X tele a lot because the image quality is very good matched with the superb Olympus 50 macro. Olympus had a 100mm macro on the 4/3 lens roadmap for six years and never got it off the ground, if it had been as good as the 50mm I would be shooting a housed E-5 at this time. It appears that Olympus will never deliver on that lens so the 2 X tele is your best choice for a long macro lens. Image quality and auto focus speed are still better than the Sigma 100 macro for the 4/3 format.
Keep in mind that the 2 X teleconverter is about twice as thick as the 1.4 X and needs a longer extension port. I have used two 1.4 X extension ports stacked and now use the Athena extension port for the Athena 200mm dome port for the 7-14 lens. This is an expensive extension if you don't use the 200mm dome for the 7-14. Athena also makes an extension for use with the 2 X tele converter.
Shots like the one attached would likely not have happened without the extra distance provided by the 2 X tele converter.
Phil Rudin
