Inferior UV mirror long zoom lens to focus the have influence

 Recent published your paper money yuan Mr Kay article "UV lens market survey and guide the choose and buy, Mr Qian mentioned in the market of UV mirror chaos, and for that I screamed to feel the same way.

 

Recently, a friend of the photography show me, these pictures are not focus, I asked him what equipment use, he said with filming ricoh XR-7 M Ⅱ type and comfortable horse 70 210 MM zoom lens. The video friends insisted, it may be suitable horse "false", as the camera lens. Buy ricoh original I put his cameras and lenses for trying out for us
4000
e with a tripod, sedate, the shutter release. First to that one test, the shooting horse comfortable lens a roll of black and white film, flushing it out of the photograph also not clear, no one is $coke, is a lens is there a problem? Not likely. This only comfortable horse 70 210 MM zoom lens, buy time is not too long, and without the collision.

 

I picked up the camera lens, carefully observe the object from cameras viewfinder to watch, the subject very clear, crack can close, like coke but always feel object before, after partial partial. I began to think that in front of the cameras UV mirror won't have a problem, remove the casual medal, and lift up the domestic UV lens camera focus the object, and then screw in the UV lens focus, not consciously repeatedly made DuoCi, now, put on the focus of the UV mirror, moved forward, and take down the UV lens focus and coke after normal. Then seek to tape measure, to the camera and the distance of the object made a measurement, not with the focal length of the UV mirror, and normal installed on the UV mirror the focal length of the before and after partial partial many, in 1.5 meters of objects, mount UV mirror of 210 MM lens with the focus, the object is pushed to 1.6 meters or so, yet in the 200 MM the following the focal length of the section and moved forward to 1.3 meters or so, this kind of situation reflects on film to be FaXu? And I will be the standard lens mount UV mirror for comparison, but this medal UV mirror into standard head no error, the focal length, all the focus is normal.

 

So it seems, inferior UV mirror not only influence telephoto zoom lens focus, also cannot have block UV role, the serious influence zoom lens image quality, make focus deviation, cause image blur.

 

This medal IN CHINA with photographs MMUV lens, if such as 52 after he said: "if IN the white paper, lens is extremely under foil shallow pale green. I'm afraid to doubt glass lens is......." This commemorative lens is shown shallow green, it could really is "ordinary glass molding lenses." cut