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CaK from 6. March - new season 2013!

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#1 HPaleske

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Posted 09 March 2013 - 01:02 AM

At 6.3.2013 was the new observing season opens. The instrument has not changed from the previous year. Is used the 225mm Unigraph with Lunt CaK filters.

Here are two results. Note the marked structure in the second picture. I 'm not sure how I need to evaluate them morphologically.

http://www.unigraph....01-11-08-30.jpg

http://www.unigraph....15-11-28-11.jpg

In March , the sun is in Germany is still relatively low on the horizon , and often head over a cold flow from Scandinavia. Therefore, the seeing conditions for CaK are very bad. Nevertheless , many structures clearly. In the coming weeks , the atmospheric conditions are better.


cs Harald
www.unigraph.de

#2 steveward53

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Posted 09 March 2013 - 01:41 AM

Great to see you back sir , I assumed you were hibernating.

I look forward to your fantastically detailed images.

#3 raylal

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Posted 09 March 2013 - 07:18 AM

Glad to see you back and impressing us as usual with your superb images. Thanks for sharing.

Ray

#4 BYoesle

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Posted 09 March 2013 - 11:10 AM

Pretty astounding given the solar altitude Harald! Good to see you back in action :)

#5 HPaleske

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Posted 09 March 2013 - 11:33 AM

Hi all,

thanks for your answers.

In the next time I will build a special FH 150/1200 CaK telescope that requires no mirror. This is the image contrast can be increased. I hope that the instrument will be ready in May.

cs Harald
www.unigraph.de

#6 sullij1

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Posted 09 March 2013 - 12:28 PM

Gook luck with the new instrument and thanks for the post.

#7 Andy Devey

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Posted 09 March 2013 - 06:31 PM

Brilliant Harald

Regards

Andy

#8 marktownley

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Posted 10 March 2013 - 03:50 AM

Excellent images Harald!

How are things progressing with your 'double stacking' of CaK filters? We're having some very interesting discussion about narrowing the CaK bandpass over here http://solarchat.nat...ar-scope-mod...

#9 HPaleske

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Posted 10 March 2013 - 05:47 AM

Thanks,

Mark: interesting link.

The pictures were taken with the double stacking CaK Luntfilter. It is a relatively expensive process , to increase the contrast of the image with two filters on. However, I know of no better way for us amateurs , if the price is to remain affordable.

The exposure time was 1/30sec and the Gain was 500 (DMK 31), 75 frames was stacked.

cs Harald
www.unigraph.de

#10 marktownley

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Posted 10 March 2013 - 07:02 AM

Thank you Harald. Can I ask what the focal ratio of the beam was as it passed through the CaK double stack? Another way you might want to consider that will increase contrast would be to collimate the beam from the unigraph, then pass it through the CaK filters, then refocus it - much the same way as in a Ha PST for instance.

Mark

#11 HPaleske

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Posted 10 March 2013 - 07:43 AM

Mark,

the focal ratio of the beam was about 1:12 - 1:14.

To work in this relative big half- width of about 1.5 A ( double stack ) does not need the telecentric beam path. Professionel calcium Lyot filters have a FWHM of 0.3 A. This is necessary to the filters in the parallel beam to place.


The filters have only a small diameter and can stand only at certain points in the beam path – for example, just before the camera chip or on a Lyot diaphragm.


cs Harald
www.unigraph.de

#12 marktownley

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Posted 10 March 2013 - 08:08 AM

Hi Harald, Thanks for that. Do you have picture or diagram of the CaK double stack unit you are using / have made on your website at all?
Thanks.
Mark

#13 HPaleske

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Posted 10 March 2013 - 10:57 AM

Mark,

The double stack unit has been installed behind the Lyot stop in the unigraph beam.

Soon I will make a photo of it.



cs Harald
www.unigraph.de






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