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Zerochromat for DSO astrophotography?

astrophotography dso refractor
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#1 sifan

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Posted 20 September 2020 - 12:16 PM

I'm looking at the 10" F/12 Zerochromat and wondering how this would perform for deep sky photography?  Does anyone have experience doing this?  In the research I've done, it's mentioned how nicely it performs for visual and planetary, but I have not found anything regarding DS.



#2 dan_1984

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Posted 20 September 2020 - 12:28 PM

F12 seems “slow” to image with. It can be done, but it takes longer and because of high magnification you need a very good mount... 


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#3 altair1956

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Posted 29 September 2020 - 10:02 AM

I was also considering a zerochromat about 2 years ago. I got to try the 8 inch version for a while. It did nicely on planets, but I did not like it at all for DSOs.

I found that compared to a 6 inch other type of telescope I had, it didn't put thru as much light and all DSOs were dim. The planets were dimmer than my 6 inch too. There's something about the tube holding the correcting lenses inside the zerochromat that seems to throttle the amount of light going thru the system. It performed no way near what you would expect with an 8 inch aperture in my opinion. 


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#4 Mitrovarr

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Posted 29 September 2020 - 12:13 PM

Between the physical size and the slowness, I can't even imagine the behemoth mount that would take.

#5 HydrogenAlpha

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Posted 29 September 2020 - 09:41 PM

No experience with this, so I can't advise in that regard. 

 

However, I don't see why you'd want to do it. As others have already mentioned, it is a very slow scope at f/12. Even an SCT or RC would be faster. I get that you might want the pinprick stars associated with refractors, but there are many other alternatives if you're willing to use smaller apertures (in the 6" range).

 

At 3000mm FL, you're going to be heavily oversampled for DSOs with the exception of the very largest of pixels (~15 microns). I assume you're targeting the ZC because of it's low CA. But at f/12, any ED doublet is going to show practically zero CA. Considering the price of the zerochromat, a 180mm (7") triplet might be a better alternative for what you want to do. It will give you a much wider FOV and speed without loss in resolution for normally-sized pixels. 



#6 39.1N84.5W

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Posted 01 October 2020 - 02:03 PM

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