Advise needed

[bidptl]

社長 and/or other experts .... I am using ND filters for my prosumer cam and the Sun comes out white in color.
What filter should I use if I want to get the correct yellow/orange-ish color while filtering the brightness of the Sun ??
Appreciate your advise ....

cheers/Peter

[David]

社長 and/or other experts .... I am using ND filters for my prosumer cam and the Sun comes out white in color.
What filter should I use if I want to get the correct yellow/orange-ish color while filtering the brightness of the Sun ??
Appreciate your advise ....

cheers/Peter

You may consider filters by Thosand Oaks.

[willis]

Sunlight is not yellow/orange-ish, when u reduce the intensity to a safety level by neutral filter. Sunlight is reddish yellow during sunset or sun rise due to scattering. The color of sunlight at noon is in fact light pale yellow which is close to white. The color of most solar images is added by post processing. Some filters which is not neutral and give u color, say Thousand Oaks. This just likes sun glasses have colors. A brown sun glasses give u brown. A yellow sun glasses give u yellow. Thousand Oaks just gives u reddish yellow.

[bidptl]

thanks Willie,

so that means the ND filters is not changing the color as it is indeed almost white for the sun say above around 10 degree either at sunrise or sunset ... ic ic ..many thanks .... here are my Venus transit pics .. I thought the ND filters altered the color at the beginning .... next time I wont use digital zoom as they all came out blur ... (well I am just a beginner )
https://www.facebook.com/media/set/?set ... f060d7d544

one more question - my friend told me I can try hydrogen alpha filter, I check on the web that it limits the wavelength of the light coming through, some sample pictures are yellow and some are red ... so .. are there different H alpha wavelength filters or the difference is due to post processing ??

many thanks and apologies for so many questions ...

[Lewis]

Normally, the light spectrum of sun is just like below.


When you took a photo at very very low angle (around 10 degree), sunlight will be scattering by thicker atmosphere that you will see the sun turning into red in colour.

H-Alpha range is look like below.

http://www.astropix.com/HTML/I_ASTROP/DSLR_HA.HTM
If the white balance is set correctly, you will get a reddish yellow sun only.

[willis]

one more question - my friend told me I can try hydrogen alpha filter, I check on the web that it limits the wavelength of the light coming through, some sample pictures are yellow and some are red ... so .. are there different H alpha wavelength filters or the difference is due to post processing ??

The wavelength of Ha is 656nm. Different Ha filters' transmittance is peak at 656nm, but with different bandwidth. Most Ha photos are taken by mono camera.So the image or video files are black & white. The color is just added in the post processing.

[社長]

hello Peter,

see this,

http://starizona.com/acb/basics/equip_f ... solar.aspx

"Observers sometimes use an orange colored filter to make the sun look the color people expect to see, but the image quality is fine no matter the color."

我少年時用的是日本那些Herschel wedge及小濾鏡，後來玩過Thousand Oaks的不同濾鏡：

viewtopic.php?f=10&t=2978

發現Baader film的效果會好一點(也可能是我的望遠鏡質量比往時好)，但最效還是現時的APM/Lunt或Baader等的Herschel wedge加上合適的濾鏡，其中拍攝或觀測米粒組織會容易一些，就算在無點子的日子，太陽仍會呈現為一個很有層次感，中央比週邊亮，呈立體的氣團，我當時設計日行跡時也用這設定。坦白說，用了Herschel wedge便不會回頭用Baader film了，除非是沒有辦法。

viewtopic.php?f=12&t=341

若要用相機或攝像機拍攝，那只有用Baader film或其他濾鏡了，若你喜歡橙紅色調，如David所說就買Thousand Oaks吧。

[bidptl]

many thanks 社長. Really appreciated.

I'll try these filter and technique to try to improve ....