Advice for new Quark based setup

[Notty]

Hello sun worshipers! Apologies if this should be in the scope discussions section, but after a long hiatus I am considering splurging out again for some solar imaging kit. I had a modded PST/Tal which I sold a while back through disuse but now have a bit more time, and I think I will have more opportunity to image from the obsy in the day than at night.  Anyway, I was wondering what the best imaging setup I could get for around £2k would be. Camera is a ASI 1600mm mono, and I want the highest resolution imaging I can get so am thinking large aperture refractor + Quark might be the best value for money, given the prohibitive (for me) price of the big Lunts.  Can anyone maybe with a similar setup care to share what they have, or recommend any suitable scopes? I understand will have to factor in a big ERF at anything over 80mm so that will obviously restrict scope cost.  I already have a ED80-DS as my night scope, with the addition of a stepper focuser which is obviously a big plus for solar imaging.  At f7.5 though I understand the quarks are optimised for f30 though is that right?

Any help and advice appreciated, thanks!

[Peter Drew]

F7.5 is ideal for a Quark as its incorporated 4.2X Barlow produces the optimum F30.    🙂

[Davey-T]

Hi Notty good to see you getting back into solar imaging, I use the Quark with Tecnosky 152mm refractor, same as Altair version, and PG Blackfly camera, often need to use a .5X focal reducer when seeing is poor though.

Dave

[LukeSkywatcher]

I have a Quark on a Bresser AR xs 102. Does me. 

[Notty]

On 11/11/2019 at 13:57, Davey-T said:

Hi Notty good to see you getting back into solar imaging, I use the Quark with Tecnosky 152mm refractor, same as Altair version, and PG Blackfly camera, often need to use a .5X focal reducer when seeing is poor though.

Dave

Hello Dave, that looks like a really nice bit of glass. Are you using the Baader 135mm ERF with it?  That's £££ cough territory!!

[Davey-T]

1 hour ago, Notty said:

Hello Dave, that looks like a really nice bit of glass. Are you using the Baader 135mm ERF with it?  That's £££ cough territory!!

Hi Notty, using an internal 2" 35nm Baader filter as you say the external ones are rather pricey, not sure how much difference it makes, Ewan gets superb images with a similar setup using the external filter but I think that's more due to his Quark being top notch, damn things are so variable despite claims to the contrary by Daystar.

Pondering on getting a faster frame rate camera at the moment, had a chat to Rupert ( Astrograph ) at IAS and it's a toss up between two with one having twice the download speed and costing twice as much.

ATB

Dave

[Craney]

On 11/11/2019 at 15:59, LukeSkywatcher said:

I have a Quark on a Bresser AR xs 102. Does me. 

Do you image with this ?? ....  or  purely visual ??     I have the same scope for wide night-time rich field views.     Does this aperture warrant an external ERF  ??

[Notty]

46 minutes ago, Davey-T said:

I think that's more due to his Quark being top notch, damn things are so variable despite claims to the contrary by Daystar.

Oh dear, I'd heard all about that when they came out but had hoped that all these years later they might have improved QC in their manufacturing.  If they're still a big gamble I might have to have a rethink until I can afford said Lunt 😞 Thanks for the info Dave

[Rusted]

You can use an internal Baader D-ERF. I used a 90mm half way down the tube on my 150/8.
This has a similar reduction effect to an external, full aperture filter.

BUT! It has some very serious downsides:

The internal filter reflects and focuses a red hot, burning beam just outside the objective!
Which is a very serious safety issue if there are other people or children about.
I actually set fire to a forgotten, cardboard aperture stop ring I had fitted inside the dewshield.
It warped between imaging sessions and drooped into the hot beam! FIRE!

Internal filtration doesn't protect the whole instrument from heat like an external, full aperture filter.
The layout may be thermally inferior due to internal tube currents.
The red, focused beam coming from the empty focuser is still hot!

Somewhere safe and perfectly stable has to be found for the internal D-ERF to sit.
I used an original baffle for support inside my old CR150/8.
Which meant removing the objective cell from the main tube for access.
Then moving all the original baffles around to suit.
Some baffles are welded or glued into the tube so wont move easily.
Besides, you'll ruin any flocking or matt paint inside the tube.

Doing any of this will instantly void any guarantee on a new instrument.
I didn't care due to the age and "untidy" condition of my [very] secondhand refractor.

I'd strongly recommend you dig deeper for a full aperture, external D-ERF filter.

[Notty]

Very interesting information Rusted, thank you for sharing it. All food for thought. 

[Davey-T]

4 hours ago, Notty said:

Oh dear, I'd heard all about that when they came out but had hoped that all these years later they might have improved QC in their manufacturing.  If they're still a big gamble I might have to have a rethink until I can afford said Lunt 😞 Thanks for the info Dave

I have a new one supplied by Daystar last March that has stopped working.

Dave

[LukeSkywatcher]

On 19/11/2019 at 15:21, Craney said:

Do you image with this ?? ....  or  purely visual ??     I have the same scope for wide night-time rich field views.     Does this aperture warrant an external ERF  ??

I'm purely visual. 

Edited November 21, 2019 by LukeSkywatcher

[LukeSkywatcher]

You really only need an external ERF on refractors of a certain aperture, and mainly if imaging...so I've read.