How long has survived your H-alpha filter ?

Hi,

A small poll.
To update an article about H-alpha interferential filters,
http://www.astrosurf.com/lombry/reports-sunha.htm
I would like to ask a question to all owners of Daystar (ATM, T-scan),
Lumicon and other Coronado filters,

If you owned such a filter for a few (tens) years and had to replace it, how
long did you keep it in good state, how many times per month or year did you
used it (or globally how many hours/year) before he crashed or became
unsuited for its purpose ?

Did you experimented some problems before it crashed, which ones ?

Do you think that your way to use it (e.g. without ERF, too short f/D, etc)
can be the main reason of this defect ?

Have you replaced it with the same model, and if you haven't, what have you
choosen and why ?

Please list the brand, model and the scope used.

Thanks in advance

Thierry

Galleries recently updates:
H-alpha images : http://www.astrosurf.com/lombry/imag...ery-sun-ha.htm
Transit of Venus :
http://www.astrosurf.com/lombry/imag...nsit-venus.htm
and many articles written in French in the Dossier/Bioastronomy/SETI section

Thierry posted:

If you owned such a filter for a few (tens) years and had to replace it, how
long did you keep it in good state, how many times per month or year did you
used it (or globally how many hours/year) before he crashed or became
unsuited for its purpose ?

I have a DayStar 0.7 Angstrom T-Scanner which I purchased back in about 1987.
It worked very well for about 14 years (usage a few times per week) until
the blocking filter began to fail (loss of contrast and light intensity in one
side of the field). I got it repaired at DayStar for about $300 and it is
still going strong. Apparently, the early blocking filters did not last for
more than about 15 years of extensive use before they failed. Still, the
repair cost much less than buying a new filter. A friend of mine had one last
about 16 years before he had trouble with its blocking filter. I understand
that DayStar has changed the blocking filter a bit, possibly at an attempt at
a longer lifespan.

Did you experimented some problems before it crashed, which ones ?

Experimented? No, but it did get dropped once.

Do you think that your way to use it (e.g. without ERF, too short f/D, etc)
can be the main reason of this defect ?

No, it looks to be a mere longevity issue of the blocking filter. I never
used mine without the ERF (DayStar specifically tells you *not* to use it that
way or it *will* hurt the filter). The focal ratio has to be f/30 or longer
for it to work properly, so that has never been a factor either.

Have you replaced it with the same model, and if you haven't, what have you
choosen and why ?

If this one eventually goes south, I will probably replace it with a narrower
filter from Solar Spectrum. DayStar's service seems to be rather slow just now.

Please list the brand, model and the scope used.

DayStar 0.7 Angstrom T-Scanner (90mm ERF), used on Orion StarMax 90mm EQ
(87.5mm f/14 Maksutov-Cassegrain, with TeleVue 2.5x Powermate, yielding
f/39.5). Clear skies to you.


--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

Thierry posted:

If you owned such a filter for a few (tens) years and had to replace it, how
long did you keep it in good state, how many times per month or year did you
used it (or globally how many hours/year) before he crashed or became
unsuited for its purpose ?

I have a DayStar 0.7 Angstrom T-Scanner which I purchased back in about 1987.
It worked very well for about 14 years (usage a few times per week) until
the blocking filter began to fail (loss of contrast and light intensity in one
side of the field). I got it repaired at DayStar for about $300 and it is
still going strong. Apparently, the early blocking filters did not last for
more than about 15 years of extensive use before they failed. Still, the
repair cost much less than buying a new filter. A friend of mine had one last
about 16 years before he had trouble with its blocking filter. I understand
that DayStar has changed the blocking filter a bit, possibly at an attempt at
a longer lifespan.

Did you experimented some problems before it crashed, which ones ?

Experimented? No, but it did get dropped once.

Do you think that your way to use it (e.g. without ERF, too short f/D, etc)
can be the main reason of this defect ?

No, it looks to be a mere longevity issue of the blocking filter. I never
used mine without the ERF (DayStar specifically tells you *not* to use it that
way or it *will* hurt the filter). The focal ratio has to be f/30 or longer
for it to work properly, so that has never been a factor either.

Have you replaced it with the same model, and if you haven't, what have you
choosen and why ?

If this one eventually goes south, I will probably replace it with a narrower
filter from Solar Spectrum. DayStar's service seems to be rather slow just now.

Please list the brand, model and the scope used.

DayStar 0.7 Angstrom T-Scanner (90mm ERF), used on Orion StarMax 90mm EQ
(87.5mm f/14 Maksutov-Cassegrain, with TeleVue 2.5x Powermate, yielding
f/39.5). Clear skies to you.


--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

For what I know this the coating that weakens after more than 10 years of
usage (once a week or month)
But as you say to be able to keep in in good state since 1987, even after
one servicing look great. This is a good investment... Even my transceiver
and my car didn't last so long ;-)

Thierry, ON4SKY

"David Knisely" wrote in message
...
Thierry posted:

If you owned such a filter for a few (tens) years and had to replace it,
how
long did you keep it in good state, how many times per month or year did
you
used it (or globally how many hours/year) before he crashed or became
unsuited for its purpose ?

I have a DayStar 0.7 Angstrom T-Scanner which I purchased back in about
1987.
It worked very well for about 14 years (usage a few times per week)
until
the blocking filter began to fail (loss of contrast and light intensity in
one
side of the field). I got it repaired at DayStar for about $300 and it is
still going strong. Apparently, the early blocking filters did not last
for
more than about 15 years of extensive use before they failed. Still, the
repair cost much less than buying a new filter. A friend of mine had one
last
about 16 years before he had trouble with its blocking filter. I
understand
that DayStar has changed the blocking filter a bit, possibly at an attempt
at
a longer lifespan.

Did you experimented some problems before it crashed, which ones ?

Experimented? No, but it did get dropped once.

Do you think that your way to use it (e.g. without ERF, too short f/D,
etc)
can be the main reason of this defect ?

No, it looks to be a mere longevity issue of the blocking filter. I never
used mine without the ERF (DayStar specifically tells you *not* to use it
that
way or it *will* hurt the filter). The focal ratio has to be f/30 or
longer
for it to work properly, so that has never been a factor either.

Have you replaced it with the same model, and if you haven't, what have
you
choosen and why ?

If this one eventually goes south, I will probably replace it with a
narrower
filter from Solar Spectrum. DayStar's service seems to be rather slow
just now.

Please list the brand, model and the scope used.

DayStar 0.7 Angstrom T-Scanner (90mm ERF), used on Orion StarMax 90mm EQ
(87.5mm f/14 Maksutov-Cassegrain, with TeleVue 2.5x Powermate, yielding
f/39.5). Clear skies to you.


--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

For what I know this the coating that weakens after more than 10 years of
usage (once a week or month)
But as you say to be able to keep in in good state since 1987, even after
one servicing look great. This is a good investment... Even my transceiver
and my car didn't last so long ;-)

Thierry, ON4SKY

"David Knisely" wrote in message
...
Thierry posted:

If you owned such a filter for a few (tens) years and had to replace it,
how
long did you keep it in good state, how many times per month or year did
you
used it (or globally how many hours/year) before he crashed or became
unsuited for its purpose ?

I have a DayStar 0.7 Angstrom T-Scanner which I purchased back in about
1987.
It worked very well for about 14 years (usage a few times per week)
until
the blocking filter began to fail (loss of contrast and light intensity in
one
side of the field). I got it repaired at DayStar for about $300 and it is
still going strong. Apparently, the early blocking filters did not last
for
more than about 15 years of extensive use before they failed. Still, the
repair cost much less than buying a new filter. A friend of mine had one
last
about 16 years before he had trouble with its blocking filter. I
understand
that DayStar has changed the blocking filter a bit, possibly at an attempt
at
a longer lifespan.

Did you experimented some problems before it crashed, which ones ?

Experimented? No, but it did get dropped once.

Do you think that your way to use it (e.g. without ERF, too short f/D,
etc)
can be the main reason of this defect ?

No, it looks to be a mere longevity issue of the blocking filter. I never
used mine without the ERF (DayStar specifically tells you *not* to use it
that
way or it *will* hurt the filter). The focal ratio has to be f/30 or
longer
for it to work properly, so that has never been a factor either.

Have you replaced it with the same model, and if you haven't, what have
you
choosen and why ?

If this one eventually goes south, I will probably replace it with a
narrower
filter from Solar Spectrum. DayStar's service seems to be rather slow
just now.

Please list the brand, model and the scope used.

DayStar 0.7 Angstrom T-Scanner (90mm ERF), used on Orion StarMax 90mm EQ
(87.5mm f/14 Maksutov-Cassegrain, with TeleVue 2.5x Powermate, yielding
f/39.5). Clear skies to you.


--
David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************