Re: Macro Lens
I always advise using a tripod for macro work, as light can be a problem if for no other reason than small apertures are required, due to shallow depth of field. A ring flash or a pair of matching speed lights mounted either side of the lens can give shadowless light.
A proper macro lens at the end of the day is possibly the best option, but not nessesarily as there are advantages with tubes.
I found using a longer lens even up to 200mm on tubes gives good macro images without having to get as close to the subject. Depth of field again can be a problem.
The Kenro tubes are indeed a finer quality that the one I described, I have just looked they are branded Fotga but they are still not at all bad and as I said they still support your lens functions to camera. Tubes are not optical items so image quality is not effected whether expensive tubes or cheap ones are used.
However if a lot of macro work is anticipated then it makes sense to get the best affordable.
All the reviews I have read rate the Olympus very highly but also the Leica/Lumix version, but the Olympus has a lower price rag, well it's not got Leica written on the barrel has it.