Single vs Double Stack Image

[Sunshine]

It would be interesting to see a particular solar image done in both single vs double stack, i had a single stack Lunt and will soon buy another but, i would like to see what i would be missing comparing to a double stack.

If anyone has a comparison they can post i'd love to see it, thanks.

[Merlin66]

On the Daystar site they have a series of solar images showing the improvement in contrast as the bandwidth reduces.

I have many single and double stack images but not of the same AR etc.

 

[Merlin66]

The SolarChatForum has many images taken with different combinations of filters.

well worth checking out.

[Altocumulus]

I second solarchatforums for that kind of comparison.

Interestingly, some prefer single rather than double, so it may also turn out to be a very personal choice. Not much good unless you can test yourself before purchase!

[Montana]

I have a recent comparison but I was still getting used to the PGR Chameleon and the Sun wasn't that brilliant either so the images are a bit dull. This is with the PST.

Single stack

Sun_115002_22_11_2020_f colour by Alexandra Hart, on Flickr

Double stack

2020-11-22 full disc 1-6x Chameleon f colour by Alexandra Hart, on Flickr

Alexandra

Edited December 14, 2020 by Montana

[Sunshine]

2 hours ago, Montana said:

I have a recent comparison but I was still getting used to the PGR Chameleon and the Sun wasn't that brilliant either so the images are a bit dull. This is with the PST.

Single stack

Sun_115002_22_11_2020_f colour by Alexandra Hart, on Flickr

Double stack

2020-11-22 full disc 1-6x Chameleon f colour by Alexandra Hart, on Flickr

Alexandra

Thanks for this comparison! maybe it’s my phone screen but the difference is big, I can’t see a prom at the 1 o’clock position in the first image which is glaring in the second.

[Luke]

Proms should be brighter in the single stack. The double stack image looks flatter and more contrasty to me, the single looks more "spherical"/ball-like. I prefer the double, but the single is lovely and very detailed too.

Alexandra, how are you finding the new camera?

Edited December 14, 2020 by Luke

[Kitsunegari]

There are some filters on ebay sold by A_p_o_l_l_o which produce a "pseudo-double stack" at the eyepiece(1.5 angstrom).    Apollo stripped ~9 angstroms off the usual mass produced blocking filter offered by lunt and coronado,  Which is a huge amount of bandwidth. 

 

the difference between a second etalon is the additional stripping of 12  more angstroms before the eyepiece (depending on if you are shipped a good etalon).   Apollo's filter is very close to getting a true double stack(thus the pseudo-prefexi).  He developed that filter with Andover optical corp and its made in the USA.

 

 

Long story short, if you want to be part of his experiment; find him on ebay.

[Altocumulus]

5 minutes ago, Kitsunegari said:

There are some filters on ebay sold by A_p_o_l_l_o which produce a "pseudo-double stack" at the eyepiece(1.5 angstrom).    Apollo stripped ~9 angstroms off the usual mass produced blocking filter offered by lunt and coronado,  Which is a huge amount of bandwidth. 

 

the difference between a second etalon is the additional stripping of 12  more angstroms before the eyepiece (depending on if you are shipped a good etalon).   Apollo's filter is very close to getting a true double stack(thus the pseudo-prefexi).  He developed that filter with Andover optical corp and its made in the USA.

 

 

Long story short, if you want to be part of his experiment; find him on ebay.

Interesting!

[Montana]

Luke, the reason for not seeing the proms in the single stack and seeing them in the double stack is because the dynamic range changes. The eyeball in single stack can see the proms more easily but the dynamic range is large and therefore bad for the camera. In double stack the whole image is darker but more even and therefore the dynamic range is closer together so the camera can see the surface and the proms together. 

The Chameleon is excellent for the PST (better pixel size for resolution) but the Newton's rings are horrible! I'm getting there with the help of software for pattern suppression  However the DMK41 still has better dynamic range even if the resolution is worse (and no NRs).

Alexandra