Yoshizen's Blog

The Moon of 15th August

As I said, in the old Moon calender 15th August is always full moon. So, to have a full moon tonight was just a coincidence and I found her behind a tree at rather late 22:00.

—– I took the pictures of the full moon many times, using Tamron SP 500 mm lens. But I didn’t want to do the same on this time, so took a picture of her with a kind of ordinary lens = Leiz Elmarit P 50 mm F 2.8 projection lens (costed me £1) modified to use on the Nikon Z camera, because, it was not a very sexy image with fuzzy lens. —– And after I open a photo on a PC screen, I noticed that there was a reflection of my room on the window glass = Oh, no, I should have put light off. How careless I was. The moon of 15th August has gone and we never have another chance for re-take. (Next full moon is not the 15th August one) We have only one life.


Sony lens myth (3)

Some time ago, I wrote about the strange behaviour of the Sony 30 mm F3.5 Macro lens when it was mounted on the other camera. (Sony lens moves their focus while the lens was not mounted on their Sony camera, = even without having connected to the power.


In fact, I’ve written about the Chinese made NEX-NZ lens mount adaptor, in a postscript in the Homemade NEX-NZ adaptor post.

While testing this Chinese adaptor with Sony / Zeiss 55 mm 1.8 lens on Nikon Z7 camera, I noticed that this lens behaves same as to 30 mm F3.5 lens.

Those 6 photos above are the continuous shot showing how this 55 mm lens moves its focus when the camera was aimed to the outside. The lens moves its focus from Close to infinity then to very close again, obstructing anybody’s attempt to use the lens anywhere else of the Sony camera.

—– It is quite natural that the camera Co, hate other made lens used on their camera, but why they need to block their lens used / tested on the another camera ? — Is that because the lens needed to be used with their own correction program such as Chromatic, Distortion correction built into their image procesor ?

As I wrote it before, the most interesting question is, what kind of device or mechanism made such function works. —– the focus motor might be a silent stepper motor kind (but it makes some noise) though, what sort of the power back-up system maks its function keep working, —– how it retains the power without having the trouble of re-charge ? ? ? ? — small battery or super capacitor kind ? (Sony didn’t give any answer for those inquiry. — and I haven’t disassembled and checked inside of the lens yet.)


Sony Lens Mystery (2) — After Sony’s answer


On the time of the first discovery of the strange phenomenon, inside of a Sony’s 30mm Macro lens, I gave an enquiry to the Sony.   And I got an answer from them which said :

“With reference to your enquiry and after further investigation, we would like to highlight that the Sony lens does not have a special technology used. Therefore, the focus resetting does not have to do with specific technology used inside the lens.


As they didn’t answer why and what for the lens focus move, I check the lens and found that even after more than 10 days, as I haven’t touch the lens (and the lens hasn’t been mounted to the Sony body = battery or super-capacitor if there was any at all inside, must be exhausted) the focus still moves.   So, I further gave them an even harder test, “with 10 mm extension ring”. (photo top)


On Nikon-Z7, the Sony SEL30m35 lens + 10 mm extension ring made quite a good close-up images and this was the closest I could go. (photo left)   And a bit more distance, lens worked almost on AF mode. (photo middle)  Then — while lens was kept aimed to dark object, I suddenly moved the lens (camera) to bright outside = the lens focus moved to far (photo right) then back  to very close.  M m m ? ? ? —– wait a moment, the LENS got 10 mm extension ring too.    How come the focus to far subject like the photo right here was possible ?    What kind of optics can override the 10 mm extension of the focus by a little movement of the lens ! ? ? ?    It’s incredible. 


So, I did test the same on Sony A7R body.   The result was as you can see on those photos.  = With 10 mm extension, the lens can give only very closed images (photo left) and the middle and the right photo.

With a bit of cynical view, this lens SEL30M35 (30mm Macro F3.5) can give more on the Nikon Z (with my special adapter) —– than on the genuine Sony body.   😀     What ever the Sony says, the lens keep move the focus while detecting the own position without power, as if its got own mind.  This must be their special technology used inside of this lens.   So, the mystery was not solved at all.   😀 

(Sony might got quite a confidence to ignore a funny question, even after the Canon and the Nikon came into the full frame mirrorless market, Sony’s share is still over 60%.)


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