Takahashi FSQ 85 ED 光學討論

[昇仔]

Angus, is it possible that it is a problem with the 5D??

Not quite likely....

[MANDII]

I suggest very simpily we can seperate the problem , before we get the indepth conclustion so early .

1. check the source photo have this symtoms .
2. adjust the processing part once again to see if we can improve the situation .

If the source photo also got this problem , it's the physical matter( scope / camera /optics ) .
If this problem is solved by step 2 thorugh processing , that means it is just the processing matter .

[昇仔]

If we are taking about the dark bands, I am quite sure it is the not a processing problem. Because I remember I got this in the RAW photo of Deneb.

[Wah!!]

Another thing you may try, directly see the image with an eyepiece.
I guess you won't find the dark bands on street lights/ stars surrounding the center of the field.

Maybe anguslau's guess is correct?

[willis]

I found similar phenomena happened in FSQ-85, but not in FSQ-106 or Astrophysics refractors, in this cooled DSLR website's gallery.

http://www.centralds.net/en/index.htm
http://www.centralds.net/bbs/zboard.php?id=images

[syyuen168]

Would this mean that it is an inherent optical problem of FSQ 85 but not FSQ 106?? [疑惑] [疑惑]

I found similar phenomena happened in FSQ-85, but not in FSQ-106 or Astrophysics refractors, in this cooled DSLR website's gallery.

http://www.centralds.net/en/index.htm
http://www.centralds.net/bbs/zboard.php?id=images

[鄧登凳]

....I notice that the brightest stars in your image display some peculiar flare patterns. It is very similar to my previous attempts in the past. I always thought that they are due to some abberration of Canon long lenses. Since now you are using the FSQ85, I now suspect such flares are coming from DSLRs...

May I know are you talking about the following two stars (as shown in pictures A & B)

Pictures 1 & 2 indicate the similar phenomenon in set-up of Nikon 300mm lens + Canon 350D.

I think the effects are not with the lens/telescope systems, not with the cameras and not with the processing.

My speculation is that these are partially resolved double stars and multiple stars system.

Dr. Tong's pattern A is Sigma-Scorpii, which is a quad stars system. It comprises of Sigma-Scorpii A, with is actually an esclipsing double and 0.5 arc second away, Sigma-Scorpii C and 20 arc seconds away Sigma-Scorpii B. With blooming and flare, these four stars cannot be resolved but the system would not give a round star. This is the same stars system captured by Peter in 2.jpg.

Dr. Tong's pattern A is Antares (Alpha-Scorpi), it is a double star system with a separation of 2.18 arc seconds. Too closed to be resolved by scope of 300mm to 400mm. However, again not a round light pattern is to be expected.

Peter's 1.jpg is 22 Scorpi, it is a triple star system. However, I do not have data about the separations of the stars in the system. However probably two very close stars cause flare pattern that is not round in shape.

[PeterPeter]

.......I think the effects are not with the lens/telescope systems, not with the cameras and not with the processing.
My speculation is that these are partially resolved double stars and multiple stars system.

回顧近期高兴老師影的同一星區都有這現象
http://www.hkastroforum.net/viewtopic.p ... 2%E7%9B%A4

好可能大家影到的是星雲實際外觀,而不是甚麼器材的問題喎

[Wah!!]

.......I think the effects are not with the lens/telescope systems, not with the cameras and not with the processing.
My speculation is that these are partially resolved double stars and multiple stars system.

回顧近期高兴老師影的同一星區都有這現象
http://www.hkastroforum.net/viewtopic.p ... 2%E7%9B%A4

好可能大家影到的是星雲實際外觀,而不是甚麼器材的問題喎

相中穿過恆星的暗帶是垂直於畫面中心方向的, 而且形狀相似, 我不相信這是天然形成的雲氣外觀.

另外也不像是有如牛頓副鏡架那種繞射形式產生的, 因為牛頓鏡的繞射光芒, 在整個畫面方向都是一致的.

[MANDII]

It's surely not proccesing matter as Sing zai said the raw photo also have this problem .
Similar stars shows such symthom as Mr.Deng said .
The stars are bight indeed . You can see in both Sing zai photo and Angus photo , Only those bright stars(DSO) show this .
Other small stars will never show this . I am sure there should have similar star type ( the one Dengs said )among the other small stars ,
but why they don't show this problem ? Why only big stars shows this ?
It means the lighting ( bright star ) cause this , Actually .

And the lighting can be performed differntly under differnt scope , as willis picture galary reviewed this as well ,
So , I would say this is the matter of scope/lens under differnt lighting amount of stars .

[鄧登凳]

.......I think the effects are not with the lens/telescope systems, not with the cameras and not with the processing.
My speculation is that these are partially resolved double stars and multiple stars system.

回顧近期高兴老師影的同一星區都有這現象
http://www.hkastroforum.net/viewtopic.p ... 2%E7%9B%A4

好可能大家影到的是星雲實際外觀,而不是甚麼器材的問題喎

不是星雲, 是雙星或多星的問題。 如你的1.jpg 是天蠍22號星, 是個三星系統, 而其中兩顆星很近, 鏡分不開, 但又不會是圓形。(Agnus的中間圖都是這個物體, 但他的圖還有一個謎團)

以下是由WIKISKY.ORG出來的22 Scorpii, 放大了可以清楚分出雙星 , 及光芒中間的暗線

[昇仔]

This is probably not the case. Attached is a raw image of the North American Nebula I took. The star on the upper left is Deneb. It is not a binary star, but the pattern still appears as shown in the enlarged view on the right.

[鄧登凳]

This is probably not the case. Attached is a raw image of the North American Nebula I took. The star on the upper left is Deneb. It is not a binary star, but the pattern still appears as shown in the enlarged view on the right.

I am puzzled by Tau-Scorpii in Agnus' photo. That is not a binary system as well. So this adds to the puzzle.

[willis]

Would this mean that it is an inherent optical problem of FSQ 85 but not FSQ 106?? [疑惑] [疑惑]

I found similar phenomena happened in FSQ-85, but not in FSQ-106 or Astrophysics refractors, in this cooled DSLR website's gallery.

http://www.centralds.net/en/index.htm
http://www.centralds.net/bbs/zboard.php?id=images

This is not always happen in FSQ-85 photos. But once it happen, it seems that is occurs in very bright stars only and it is FSQ-85, not FSQ-106. Here are other examples from China (one needs to login the forum to see the photos)
http://www.astronomy.com.cn/bbs/thread-121849-1-5.html

Or check it out from Google using "fsq-85":
http://www.google.com.hk/images?q=fsq-8 ... 18&ndsp=18

May be partially due to the optical design or QC. I am not sure....

[syyuen168]

QC problem from Takahashi for a top end scope

Would this mean that it is an inherent optical problem of FSQ 85 but not FSQ 106?? [疑惑] [疑惑]

I found similar phenomena happened in FSQ-85, but not in FSQ-106 or Astrophysics refractors, in this cooled DSLR website's gallery.

http://www.centralds.net/en/index.htm
http://www.centralds.net/bbs/zboard.php?id=images

This is not always happen in FSQ-85 photos. But once it happen, it seems that is occurs in very bright stars only and it is FSQ-85, not FSQ-106. Here are other examples from China (one needs to login the forum to see the photos)
http://www.astronomy.com.cn/bbs/thread-121849-1-5.html

Or check it out from Google using "fsq-85":
http://www.google.com.hk/images?q=fsq-8 ... 18&ndsp=18

May be partially due to the optical design or QC. I am not sure....