A question if there is a difference between the original Zhongyi Lens Turbo and version II, regarding the use of Pentax M-wide angle lenses such as the M28/2.8, which does not focus to infinity on Lens Turbo II due to that before the infinity mark on the lens the rear element of the lens and the front element of the Turbo II make contact and infinity focus is not reached.
Is this the same for the Zhongyi Lens Turbo original version?
I'm asking because I have an unbranded "Lens Turbo" purchased from Ebay (only thing printed on it is "PK-NEX"), advertised as "avoiding the blue (or green) blob in certain lights". This Lens Turbo does not collide the rear lens elements with the M 28/2.8. It's good in the center, but higly degrades the extreme corners of the image.
My question is wether the original branded Zhongyi Lens Turbo (with Zhongyi printed on it) doe's not collide the lens elements?
I also suspects that the off-center image quality is better with the original Zhongyi (not the version II, but the original version), than my iteration of the "Lens Turbo", seen in the attached image with the only printing on it "PK-NEX" and 0.73x magnification. Wery helpful if someone can verify, or dismiss this.