Stacking a LS50 to a PST.

[Merlin]

Well, I tried it and it works admirably, showing a wealth of chromospheric detail! If the LS50 has a bandpass of 0.7 angstroms and the PST is about the same, do any of you solar boffins know what the combined bandpass is?

[Merlin66]

The combined double stacked etalons will give x0.7 of the standard etalon ie a combo of 0.7A etalons give close to 0.5A bandwidth.

(I have a spreadsheet which shows this is independent of the bandwidth overlap...)

[Merlin]

Thanks for that Ken.. I intend to stay with the stack, but this leaves mer with a redundant B600 blocker. If I did a stage 2 mod on my other PST, would the B600 be big enough for just visual viewing? I'm not into imaging.

[Merlin66]

If you have a B600 handy then obviously use it...

Otherwise it just sits the the box for "future" opportunities...(like mine!)

[Merlin]

Thanks again Ken. The issue that concerns me here with the B600 is whether or not there would be some vignetting if I used it in combo with, say, a modded 80mm or 90mm/f.10 'scope. I have a 100mm/f.12 'scope that could possibly be utilised.

[The Sailor]

Merlin, can you post some information about this stacking as I am interested, parts, buying and what to do, please.

Jim

[Merlin66]

The B600 is designed for use on scopes with a focal length up to 600mm, above that, there will be some vignetting.

[The Sailor]

Found info required, thank you

Jim

[Peter Drew]

The vignetting is of the image not the aperture so there is not a reduction in the resolution.

[Merlin]

Thanks Peter. Does anyone know if the LUNT ERF is built into the front aperture etalon assembly, or incorporated into the bolcking filter end ( as in the PST )?