Opticstar 80mm F5 and some solar playing.

Frankenscope? Let's see it!***be advised that NOTHING in this forum has been safety tested and you are reading and using these posts at your own peril. blah, blah, blah... dont mess around with your eyesight when it comes to solar astronomy. Use appropriate filtration at all times...
Post Reply
Posts: 350
Joined: Fri Mar 30, 2018 6:46 am
Location: Derbyshire UK
Has thanked: 450 times
Been thanked: 164 times

Opticstar 80mm F5 and some solar playing.

Post by AndiesHandyHandies » Sun Nov 22, 2020 4:46 pm


I saw a picture for a HAT which showed a PST Mod and a Quark after a Tele-centric.

So if it works that way round will a Quark work in a collimated beam?

And just to see I thought can you have 'best of both'.

Yesterday I had a play setting up my 80mm F5 for tele-centric and collimation all at once.

I put a ES 2X Tele-extender in the focusser.
And then a -200 Collimator 80mm in front of the field stop of my 25mm Clave'.

I have a Prom Quark which has mica 'features' over a sector of 120deg on the edge but the other is clear.
Using it full field I get scatter off the feature.
So I am thinking of using a the collimator 80mm in front of focus to get a 8mm collimated beam and use a off-set 1.25' holder so I can rotate the Quark in it and pick out a 8mm circle from the good bit.

This morning I found I actually got focus on a repeater TV tower across the valley with a few mm to spare. Looked OK.

So with some Sun shine tried it with my Chromo Quark which has good mica.

Fortunately just go focus still.

However the image a bit soft due to all the glass.

Went down to telecentrics which I not ried before on this scope.

Both my ES 2X TE and a Viking 3X TE produced nice images of todays big prom.

So a possible grab and go solar scope.

I have a 100mm F5 I have used with a Macro-lens reducer to get more light into a Quark with the F4.2x Tele-centric.

So one for proms and one for chromo?

Cheers. Andrew.

User avatar
Way More Fun to Share It!!
Way More Fun to Share It!!
Posts: 1417
Joined: Tue May 09, 2017 7:58 pm
Location: Florida
Has thanked: 300 times
Been thanked: 259 times

Re: Opticstar 80mm F5 and some solar playing.

Post by MalVeauX » Thu Nov 26, 2020 12:02 pm


I did a Quark first, then PST etalon after the Quark without its lenses. The Quark has its own telecentric, so the etalon is then sitting in that and it's over F30, etc depenging on your setup, so the PST etalon is happy. Just clock it and tune it and you have a double stack. It'll have a small sweet spot. But it works. Depending on your two filters, it will be very dim requiring lots of gain or longer exposure time, so needs good seeing to function best of course to avoid using tons of gain and filling the image with noise.

I did this for a while, used it on a 6" and 8" actually. Was able to eliminate the double limb. But the transmission was just too low for my liking and limited the FPS and required noisy gain at high values.

Very best,

User avatar
Posts: 29767
Joined: Tue Oct 18, 2011 5:27 pm
Location: Brierley Hills, UK
Has thanked: 2837 times
Been thanked: 1142 times

Re: Opticstar 80mm F5 and some solar playing.

Post by marktownley » Thu Nov 26, 2020 4:22 pm

Sounds like you're having fun playing Andrew

Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

Post Reply