器材相片post左去個 blog :Wah!! 寫:可否看看實物相片呢?
http://astro-noodle.blogspot.com/
I put the grating as close to the front lens as possible. I get a 60-82 screw adaptor from Apliu St. to mount the grating so that it can be rotated to adjust the spectrum along the longer side of the CCD.鄧登凳 寫:Dear PTS,PTS 寫:
Here is a cheap setup, using "objective grating", i.e. placing a grating in front of the objective lens for star field spectrums.
http://forum.hkas.org.hk/viewthread.php ... a=page%3D2
I am also assembling a " behind the objective" grating setup. I'll let you know more when I've some test results.
PTS
Your design is interesting.
Using your objective grating set up, should the grating be covering the whole of (or most of) the objective? [I note that Edmund Optics is selling 2" X 2" grating as well as sheet grating]?
Should the grating be immediately on the objective lens? Can it be placed on the dew shield?
Is there a formula to estimate the spread of the spectrum based on the line per mm and the focal length of the scope?
Regards,
Tang
我也是用剃鬍鬚的剃片做狹縫,寬度...我估有0.2~0.5mmuniverse24 寫:如果白紙反光無法明顯看見暗線,那就改用反射鏡。noodle 寫:黃昏涼返小小,會試試用白紙反光再拍過universe24 寫:對焦確實需要準確些。
如果只是普通玻璃窗口,沒有減光效果的,那麼隔著窗口拍攝也不會有太大問題。
可以嘗試使用白紙反射陽光,那就不用整個架設指向太陽了。
另外,請問你的狹縫寬度是多少?使用什麼材料製成呢?
我是用剃鬍鬚的剃片做的。
是否可以提供那兩支望遠鏡的焦距以及光柵的大小?謝謝。
我再回想了当时测试的情景,其实是当太阳被云遮盖的时候,吸收线看不见,而当有阳光直射地面的时候,无论光谱仪指向天空的那一区都可以拍摄到吸收线。Wah!! 寫:我還以為白雲散射的是帶吸叫線的光譜呢!universe24 寫:我也这么认为,但不妨看看是否真是如此,我只知道白云确实可以拍摄到连续光谱,而蓝天则拍摄到吸收线。
有機會我也要試試!
0.2还不错,0.5就过于大了。noodle 寫:我也是用剃鬍鬚的剃片做狹縫,寬度...我估有0.2~0.5mm Smile
主鏡 : Borg 76ED (500mm)
光柵 :30x30mm (1800 lines/mm)
collimator EF70-210(@210)
Hi,Wah!! 寫:光柵有無特別對邊個波長最優化?
正在瀏覽這個版面的使用者:沒有註冊會員 和 18 位訪客