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Sky-Watcher 100mmED f/9 extra info

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#1 JoseBorrero

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Posted 07 May 2013 - 08:45 PM

Here are some info I found useful about this refractor FPL-53 doublet. here my simple study. I'm using all are done with 2" baader filters. I have done similar test with the ED80T CF which is also FPL-53 and found all filters parfocal but I ned to repeat the test with evidence.

With the Sky-Watcher 100ED I found the Blue, H-Alpha and SII a bit off focus. My best solution if having installed an autofocuser with offset filters well done!

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#2 JoseBorrero

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Posted 07 May 2013 - 08:49 PM

here's my sample of LRGB even without correcting for focus at least on the Blue channel.

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#3 stevew

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Posted 07 May 2013 - 10:22 PM

Great shot Jose!

#4 leviathan

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Posted 08 May 2013 - 03:29 AM

Nice, thank you ! I also bought used 100ED recently and this is very interesting info for me. Yes, blue seems to be a bit off focus.

#5 JoseBorrero

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Posted 08 May 2013 - 11:27 AM

By the way, I think is important to know , The Star used was Alkaid, is a blue B3V main sequence star. This spectral type indicates an effective temperature of 9100 K, a diameter twice that of the sun, and a luminosity 4300 times that of the sun, and a mass perhaps 13 times that of the sun.

I'm wondering if performing a similar test on a G2V star will change the game. :question:

#6 JoseBorrero

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Posted 08 May 2013 - 10:23 PM

heres same application using Arcturus Star. A type K1.5 IIIpe orange giant star

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#7 leviathan

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Posted 09 May 2013 - 03:04 AM

Seem to be in focus for RGB this time, isn't it ? Only H-Alpha and SII seem to be a bit out.

#8 JoseBorrero

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Posted 09 May 2013 - 03:53 PM

you're right!






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