Second Etalon

[Merlin66]

Yeah,

I was lucky, the original SM60 had the external etalon......

I sold it and bought an other SM60 external etalon, then an other......to fit the ED80.

It's worked very well for me.

First image is today's arrangement....the second from 2010

[Altocumulus]

Like the hoverfly...

[Merlin66]

 

[richard ashbee]

Just been told that the DS60 may be back in stock back end of next week or early week after

[Nigella Bryant]

I use a 60mm tilt tuned double stack, red colour with my pressure tuned 60mm lunt. Bought separately and gives stunning views and image's. 

[richard ashbee]

Nigella great photo, do you think the matched Etalons need to be for the tilted and not important for a pressure tuned scope? lot to pay out if I make wrong decision- thanks

[Peter Drew]

I've seen no evidence that unmatched (even different make) etalons suffer any inherent degradation.      🙂

[richard ashbee]

1 hour ago, Peter Drew said:

I've seen no evidence that unmatched (even different make) etalons suffer any inherent degradation.      🙂

That's the problem, some says you need a match others don't - its a minefield.

Similar situation on whether a pressure tuned or tilted is better

Has Lunt provided any information to your knowledge?

[Merlin66]

When I first tried my SM60 double stack many years ago I was told the same thing - that they had to be matched.....this turned out as Trump would say to be "fake news".

The real issue is where the design CWL (central wavelength) of each etalon is located. All tilt tuned etalons are designed to sit just above (towards the red wing) the H alpha wavelength, and require some degree of tilt to move the CWL to exactly the H alpha wavelength.

In effect this means independently tilting each of the front etalons to bring them both to the same wavelength (where maximum brightness and contrast is achieved).

Certainly tuning a DS is a little more complicated, but with patience a great result can be achieved.

I've no comment on the air pressure v's tilt (or the "Richview" pressure ) tuning.

[Peter Drew]

Well Lunt wouldn't recommend a Coronado DS etalon and vice versa.  If I was in the market for a solar scope again I would buy a Lunt and their own DS etalon.  I would buy the tilt tuned version though as less to go wrong and a TTDS Lunt gave the best 60mm Ha view I've ever seen.      🙂

[Nigella Bryant]

3 hours ago, richard ashbee said:

Nigella great photo, do you think the matched Etalons need to be for the tilted and not important for a pressure tuned scope? lot to pay out if I make wrong decision- thanks

Hi Richard, I think but have no back up to my opinion in that having a pressure tuned scope gives more leeway when using the front mounted tilt tuned etalon in double stack. Just my experience and hope this makes sense.

[richard ashbee]

Had a reply from Lunt today which might help others after alot of conflicting information

 

Thank you for your email!

 

Double Stack units (2^nd etalons) can be purchased at any time and added onto your telescope. For the LS60THa telescope, both the LS50FHa and LS60FHa will couple naturally, attaching to the front objective via thread. It would not be necessary to return your LS60THa telescope to the factor or vendor in order to purchase the double stack unit.

 

Hopefully this helps!

 

Thank you!

 

Benjamin Lombardo

LUNT Solar Systems