Single Stack vs Double Stack at the limb performance 280mm.

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Valery
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Single Stack vs Double Stack at the limb performance 280mm.

Post by Valery » Wed Feb 28, 2018 12:07 am

Hi all

Here are two images I took with my trusty C11 280mm scope equipped with the ARIES full size front mounted
DERF filter. Narrow band filters were Single Stack (Quark) and Double Stack (two PST etalons).
AR2670 was at the limb and so, it was a good opportunity to test these different setups performance at the limb.

I like both case SS and DS.


Valery
Attachments
08-13-2017-UT-06h-58m-C11--SS.jpg
Single etalon
08-13-2017-UT-06h-58m-C11--SS.jpg (827.31 KiB) Viewed 386 times
08-13-2017-UT-07h-05m-C11+PST-DS.jpg
Double stacked
08-13-2017-UT-07h-05m-C11+PST-DS.jpg (590.15 KiB) Viewed 386 times
Last edited by Valery on Wed Feb 28, 2018 5:53 am, edited 3 times in total.
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Largest full size 185 - 356mm Dielectric Energy Rejection Filters (D-ERF) by ARIES Instruments.

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eroel
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Re: Single Stack vs Double Stack at the limb performance 280mm.

Post by eroel » Wed Feb 28, 2018 3:05 am

Valery:
The double stacked image looks smoother.
Both are very good images.
Best regards,
Eric.

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Re: Single Stack vs Double Stack at the limb performance 280mm.

Post by marktownley » Wed Feb 28, 2018 6:20 am

Good comparison Valery. Like Eric says the DS view looks a lot smoother. Would be interested to see what the unprocessed straight out of stacking view for each of these images is like.
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Re: Single Stack vs Double Stack at the limb performance 280mm.

Post by Montana » Wed Feb 28, 2018 10:55 am

These are super and very 3D Valery :bow :bow :hamster: I don't see any double limb effect with the Quark so it can't be the equivalent of a traditional 'single stack' level of 0.7A, it must be below 0.5A for this to occur which is equivalent to a 'double stack' PST etalon.
Alexandra

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Valery
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Re: Single Stack vs Double Stack at the limb performance 280mm.

Post by Valery » Fri Mar 02, 2018 2:27 am

I personally prefer a SS here as it is crispier and shows more delicate details. The idea was to demonstrate that a very narrow with very good finesse etalon can be close to a DS in performance.
Here the DS is less crisp only because of the seeing problem. This SS requires about 4ms exposure (allows also about 200fps) while the DS requires about 10ms exposure and allows only about 100fps. A big difference.
Visually this 0,2A etalon is stunning. The better the seeing the more advantage of such an etalon - I can use high magnifications and see the most delicate details. DS is a bit too dim for such high magnifications and it works better at medium magnifications when the tiniest details are hard to see despite a higher contrast.

A DS is good only if it is luminous enough, not a dim.
"Solar H alpha activity is the most dynamic and compelling thing you can see in a telescope, so spend accordingly." (c) Bob Yoesle.

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Re: Single Stack vs Double Stack at the limb performance 280mm.

Post by marktownley » Fri Mar 02, 2018 12:28 pm

I want to explore more use of single stack and faster frame rates as this year develops. I do hear what you're saying Valery and agree.
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