best amateur solar spectrum

[nytecam]

In case you haven't seen it @

[chiltonstar]

Wow! I like echelles.......

Chris

[the rev]

Really great video

[Merlin66]

Very nice...

There seems to be some processing resonance artifacts but the resolution is very good for a Lhires Lite spectroscope and a Lodestar camera.

Well presented.

[robin_astro]

Wow! I like echelles.......

Chris

Not an echelle, just a Littrow (a Lhires lite) More info on how it was done here

http://www.astrosurf.com/comolli/index2.htm

The claimed 0.01nm resolution is significantly higher the manufacturers specification of 0.025-0.035nm

http://www.shelyak.com/rubrique.php?id_rubrique=5〈=2

It seems there was a lot of post processing done here to generate this video from separate images including presumably artificially colouring the spectrum since it was apparently taken using a mono camera. It would be interesting to see what the original spectrum images looked like. Perhaps some sharpening was done to to make the resolution appear higher.

Cheers

Robin

[chiltonstar]

Quote: Not an echelle, just a Littrow (a Lhires lite) More info on how it was done hereRobin

Shame! I thought the opening of the clip was an echelle-type display with stacked orders, I didn't realise it was a "composite".

Does sharpening really increase resolution, or does it just change the shape of the line profile?

Chris

[robin_astro]

Does sharpening really increase resolution, or does it just change the shape of the line profile?

Chris

It just narrows the lines and gives the apearence of higher resolution by increasing the contrast between overlapping lines spaced lines. There is no new information generated as would be the case for an actual increase in resolution.

Actually I just looked at a frame at the Mg triplet from the HD version and compared it with my similar spectrum taken with a LHIRES III and a Toucam webcam (my version is the top one - an unaltered image direct from the webcam) See also my website here

http://www.threehill.../spectra_28.htm

It looks to be similar resolution (measured at 0.25A in my case based on neon calibration lamp lines)

The Lhires Lite has a lower dispersion than the LHIRES III but uses a narrower slit (which is ok on bright targets like the sun) to give about the same resolution

Cheers

Robin

[nytecam]

Not an echelle, just a Littrow (a Lhires lite)....It seems there was a lot of post processing done here to generate this video from separate images including presumably artificially colouring the spectrum since it was apparently taken using a mono camera. It would be interesting to see what the original spectrum images looked like. Perhaps some sharpening was done to to make the resolution appear higher. Cheers Robin

Fair point Robin but it was posted on Youtube where fact can blur with the [common] fiction therein. I'm also aware of the limited expertise of viewers of Youtube on astro for example - my dusk shots of Comet Panstarrs were black but in my Youtube posting appear befitting dusk shots ;-)