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岩石薄片撮影レシピ 19th Nov.2024
Rock Thin-Section Photography Recipe

岩石薄片の写真撮影は様々な方法があるが，ここでは筆者による方法を紹介する．　　
双眼実体顕微鏡を偏光顕微鏡に換える，自作偏光ユニットなどについては以下の参照されたい．
There are various methods for photographing rock thin sections, but the author's method is described here.
See below for information on converting a binocular stereo microscope into a polarized microscope, a home-made polarizing unit, etc.

http://seagull.stars.ne.jp/2018_Gadget/Polarized_Microscope/index4.html

0.経緯

最初はUSB顕微鏡でPCに画像を取り込んで撮影していた．この方法は手軽でしかも広い視野なので良かったが，いかんせん中央部はともかく周辺の像の流れがやはり気になった．顕微鏡の光学系の設計がそれほどではなかったようだ．その後も顕微鏡とCCDなどの幾つかの組み合わせを試行したが，改善せず，結局次の手法に行き着いた．

At first, I used a USB microscope to capture images on a PC. This method was good because it was easy to use and had a wide field of view, but I was still concerned about the image flow due to lens aberration at the periphery of the image, not to mention the center. It seems that the optical system of the microscope was not so well designed. After that, several combinations of microscopes and CCDs were tried, but they did not improve the results, and I finally settled on the following method.

1.LaowaマクロレンズとEOSM＋76mm顕微鏡用架台 Laowa macro lens and EOSM + 76mm microscope mount

　そんな経緯のあと．たどり着いたのはこの組み合わせ．中国製Laowaマクロレンズ　LAOWA 25mm F2.8 2.5-5X ULTRA MACRO
旧式ミラーレスCanon EOSM　http://gdlp01.c-wss.com/gds/7/0300008787/01/eosm-im-ja.pdf
顕微鏡にするための架台；最初粗動のみ，現在微動付きに交換．
https://ja.aliexpress.com/item/1005001394214499.html　
さらに架台に取り付けるパーツの製作

After all that... I finaly setup this combination.
Laowa Macro Lens LAOWA 25mm F2.8 2.5-5X ULTRA MACRO made in China
Old mirrorless Canon EOSM http://gdlp01.c-wss.com/gds/7/0300008787/01/eosm-im-ja.pdf
Mount for microscope; coarse tuning only at first, now replaced with fine tuning for pint focus.　
https://ja.aliexpress.com/item/1005001394214499.html
Further fabrication of parts to be attached to the mounts: (2)

The Latest version


最新の岩石薄片撮影装置 Our latest rock thin section imaging system	マクロレンズの架台取り付け．LAOWAレンズはCANON用のアダプタで取り付け Mounting of macro lens on a focusing unit. Laowa lens is mounted on EOSM with CANON mount adapter.

各機材の紹介（架台，カメラ，旋盤加工の台座→加工中） Introduction of the　parts (mount, camera, lathe base → under machining)	微動つきのフォーカシングユニット．これはとても良い！ Focusing unit with fine tuning. This is amazing good! https://ja.aliexpress.com/item/1005001394214499.html

Focusing EOSM on XPL(click to movie)	Focusing EOSM on PPL(click to movie)
http://yossi-okamoto.net/LAOWA/Basic/Bankawa.html	http://yossi-okamoto.net/LAOWA/Basic/Muroto_M.html

The photos are here; http://yossi-okamoto.net/LAOWA/index.html

The old version


粗動しかついていない古い架台 Old focusing Unit; only rough tuning knob	旧架台（右）と新架台（左）の比較． Comparison of old(right) and new(left) mount for the camera.

さらに古いバージョン．双眼実体顕微鏡の架台を流用（これは下部光源がある） More old version. Using a binocular stereo microscope focusing unit (this one has a under light source).	３Ｄプリンタで作ったレンズマウント．Lens mount made by 3D printer.

Parts making recipe;


こちらは架台底面にはめ込んだ自作白色LED照明．This is a home-made white LED light inserted in the bottom of the bench base.	自作照明を上から見た図．LEDまわりの回路は下記を参考に．The circuit around the LED is shown below. http://yossi-okamoto.net/Seagull_Factory/Olympus/Olympus_index.html

厚いアルミ廃材を加工してレンズアダプタを作る．まず穴あけ． A lens adapter is made from a thick aluminum block. First, drill the holes.	次に内部の取り除き．Next, remove the inside.

さらに卓上旋盤によるレンズが挿入される内側の加工．Further machining of the inside where the lens is inserted using a bench-top lathe.	さらに顕微鏡架台に乗せる外側の加工．The outside of the lens is processed to be placed on the microscope stand.

レンズにアダプタを装着．Adapter attached to the lens.	架台にアダプタを装着．Adapter attached to the focusing mount.