www.astrocafe.hk

社長 寫:有一疑問，"The light drop at the corner is about 79% that of the centre." 其實是21%或79% ?

Another typo & corrected. Should be light illumination, instead of light drop. Will I be bitten this time?

come on!

不做不錯，做事就一定會出點錯。

我自己出的報告也經常有些盲點，人家提醒才能改過來。

我到超市買食物，會選些新鮮的，對自己有益的。看人家報告也一樣。

什麼時候可以做80/600的?

社長 寫:什麼時候可以做80/600的?

Very busy! Maybe tomorrow!

I'm waiting tehreport also. That will help me to make the big decision.

thanks for those experiments and testes, i wish i could come that sat, (sat is not a holiday for me)
and thanks willis for the report

Borg 7887 got strange result...

as I was a research student, it's not surprised that experiment and real life test (in vitro vs in situ) aways show different results (especially in my medical field), it's always multifactorial.

seems optic research may got similar situation , sometimes frustrating, or we should be excited as there maybe something new which need investigation

and as I still a newb in astro, and still learning observation, and waiting for clear sky, i am not hurry for photography yet

add oil for all of us

The sky this week may not be good anyway. The moon phase is not good for DSI also. Wish the sky turns good next weekend & we can do the test again.

按理光學測試是很單簡及直觀的測試，這次有點出乎意料，當然也是學習過程之一。

若日後我造一套平行光管，便會理想得多了，例如買一枝130/1200APO加個點光源便可以。

論平場鏡，以80/480計，我更看重Zero Power的TS2，因為焦距夠短了，光圈也不小，減焦鏡只是錦上添花而已。

Cloudynights Feb11 DSLR Challenge Winner - IC443 Jellyfish nebula

80/480 with Televue 0.8x reducer :

http://www.cloudynights.com/ubbthreads/ ... ll/fpart/1

社長 寫:按理光學測試是很單簡及直觀的測試，這次有點出乎意料，當然也是學習過程之一。

若日後我造一套平行光管，便會理想得多了，例如買一枝130/1200APO加個點光源便可以。

論平場鏡，以80/480計，我更看重Zero Power的TS2，因為焦距夠短了，光圈也不小，減焦鏡只是錦上添花而已。

最近身边朋友的这支镜子到了，还没有过去看, 上次去他那还说 Flattener 的事情。

PV = 0.08 ， Seems beautiful！

Sorry! What is PV?

PV = Surface peak to valley error in units of wavelength

德國的測試：LOMO 80/480 + TS2：

http://www.astro-foren.de/showthread.ph ... S-Flattner