To Double stack, or not to Double stack

[Glosgas]

Hi,

Forgive me, but I suspect this has been discussed somewhere in this Forum many times.

I have a Lunt LS60THa, single stack. I am really impressed with the images I get of the limb of the Sun and the detail on the surface. I was wondering if the benefit of Double stacking is worth the expense. As far as I understand the Double stack will provide better contrast for surface features. What are the views of the Forum members?

[marktownley]

Absolutely!

[Merlin66]

The main gain in a DS is the dramatic improved contrast of the surface features, not so much so on proms.....

[soulvagabond]

I doublestacked my Lunt 50 with the Daystar Quark, the difference in chromosphere details is phenomenal.
It's not only about the contrast improvement, but the image becomes a lot more 3 dimensional.
Sadly, the barlow of my Quark happened to be "dirty" and I get a lot of dust on the image, which I'm trying to solve atm.
I presume, DS-ing with the front mounted etalon is going to impress you a lot.
And then.. binoviewing supposed to bring it to the whole new level...

[Montana]

Once double stacked, you can never go back

You love the single stack, but then you go to double stack and find you were missing half the Sun. even the prominences are better as they become beautiful 3D

It does take some time to get used to setting it up though
Alexandra

[Philament]

I think it depends on the sky clarity where you are. If I had the choice, I would prefer to replace my single-stack PST with a single-stack 60mm 'scope than a double-stacked PST.

[pedro]

I tried double stacking several times and I still prefer single stack images...

Haven't tried the Quark yet though

[marktownley]

Ha ha ha! Everyone has different preferences! Funny!

[Carbon60]

Definitely DS when you're ready to make the investment. I use a Lunt 60 THa pressure tuned, fitted with a DS module (tilt tuned, front mounted) and although it takes a bit of getting used to, the views are excellent for FDs.

Stu.

[Derek Klepp]

I would say for eyepiece viewing it is worth it.

[brianm910]

I have the Lunt 60 as well, I've been viewing and taking photos in single stack, however when I screw on my second filter my images disappear and I can't view anything at all. So, please tell me what I should do after I double stack in order to get images come up in Fire Cap. Increase my exposure all the way? I can't even see anything through my eye piece. I'm sure someone can tell me how to do this. I'm using a ASI ZWO 174mm camera too.Thank you!

[Merlin66]

Hmmm
The DS intensity is usually around 60% the single stack - still bright enough for general viewing/ imaging.
Just check the second filter - hold it up and look at the sun through it....
It obviously need to be tuned to match the single stack to achieve maximum transmission, but even un tuned you should still see something...
(you have removed all the covers? ;-) )

[brianm910]

Thank you, yes I have removed the covers. Let me try holding it up to the sun an tune it. I'm assuming turning the tuner will cause some kind of clarity? I had no idea how to use it when I bought it, I was told there is an advantage to having it. I turned up my exposure one time and got some image but not clear.

[Merlin66]

Hmmm
OK Holding and looking through will just ensure there are no "blockages"....basic stuff.
Tune and focus the single stack to give the best clarity, brightest image you can get.
Don't touch the single stack tuning.
Add the double stack and adjust the tilt to give the brightest image.
That should get you very close as a starting point.
Any additional "tuning" just use the front tilt adjuster. Refocus as necessary....
As mentioned the image will be fainter than single stack and the exposures a little longer.

[Montana]

Just a thought, when you add the double stack the telescope doesn't sag does it? on my PST when I add my double stack to it, the Merlin mount droops a bit (as it is heavier on the end) and the Sun just drops out of the eyepiece, I always have to lift it a little to get the Sun back in view. Fractional but enough for the camera to go dark.

Alexandra

[GUS]

I have the LS60 with the DS60F front filter and use the ASI174 as well and have no issues. If you set it up for visual as Ken( Merlin66) explined above, and you can see the sun, you should have no issue when connecting the camera.

[brianm910]

Well, I got a bit closer. I screwed on my double stack today. I did get a good view through the eyepiece. Not clear but it was there. So, I took a video and stacked it. Here is the photo I got. What do I need to do differently? My investment in the double stack is not paying off yet, lol.

[astro1949]

your DS filter is not good-- mine did that and I sent it back to LUNT -- it was de-contacted........

[marktownley]

Ouch! That's not good, that's a decontact...

[Philament]

Occasionally, DSS gives me a similar pattern when I stack constellations or DSOs.