Measurement of a DayStar PE 0.6 A

[christian viladrich]

Hi,

I've just measured a DayStar PE 0.6 A. The resulting FWHM is 0.95 A :

http://astrosurf.com/viladrich/astro/in ... 06A-S.html

Needless to say that the solar images obtained with this filter are consistent with the measured FWHM.

Here is a summary table of measurements done up to now :

http://astrosurf.com/viladrich/astro/in ... lters.html

Clear skies !

Christian

[Dennis]

nightmare..

How can this even happen in this price category.. can this be a damage from shipping?

[marktownley]

[hopskipson]

Hi,

I've just measured a DayStar PE 0.6 A. The resulting FWHM is 0.95 A :

http://astrosurf.com/viladrich/astro/in ... 06A-S.html

Needless to say that the solar images obtained with this filter are consistent with the measured FWHM.

Here is a summary table of measurements done up to now :

http://astrosurf.com/viladrich/astro/in ... lters.html

Clear skies !

Christian

That doesn’t seem like it is within spec. I’d want my money back! Think of all the customers that don’t have the ability to measure their etalon. At what f-ratio did you test it or does this not apply with how you measure? Do you have any recent images with it?

[christian viladrich]

How can this even happen in this price category.. can this be a damage from shipping?

I am afraid it is not the only one. I know at least two others like this.

[christian viladrich]

That doesn’t seem like it is within spec. I’d want my money back! Think of all the customers that don’t have the ability to measure their etalon. At what f-ratio did you test it or does this not apply with how you measure? Do you have any recent images with it?

You said it all. Not all the customers have the hability to measure their etalon. So it is kind of easy to claim big specs.

The etalon was tested by interferometry, so no f-ratio is involved there. The method is described here :

http://astrosurf.com/viladrich/astro/in ... rview.html

The math are described here :
http://astrosurf.com/viladrich/astro/in ... edure.html

Usually, I cross check this approach with a spectrometer approach, but I could not do it since it was cloudy, and had the etalon only for a couple of hours.

In any case, images done with this filter are quite consistent with the 0.9 A FWHM.

[Dennis]

How can this even happen in this price category.. can this be a damage from shipping?

I am afraid it is not the only one. I know at least two others like this.

Aha.. seems like they (company) continue to work on their reputation.

[christian viladrich]

To put things in perspective, here are some examples of image obtained with this filter and a Hat8" :

https://www.flickr.com/photos/45136795@ ... 605283841/

https://www.flickr.com/photos/45136795@ ... 605283841/

[Ljungmann]

Christian, I know you can squeeze details out in the image processing. Do you know how it performs visually? Any details at all on the “surface”? Or just a ball with spots and prominences?

[Dennis]

Yes.. those images show it, despite being colorized. Good detail of prominences and relative low surface contrast. Beautiful but not what he ordered.

[rsfoto]

Hi,

I am glad I got my money back 3 years ago ...