TheSkySearchers

I am looking for a filter for m42, your thoughts?
I know it is very confusing filters, so I ask for your help please.
there is the uhc, uhc 2, the 0iii ...... ouuuuffffff.
I'm lost . for visual only .

I don't use the uhc etc. from experience. They disappoint me by darkening the image and not enhancing contrast sufficiently.

The OIII filters only work well on planetary nebulae and won't do a thing for M42. The ionization temperature of M42 is too low to excite the line emissions appreciably. OIII is great on many planetary nebula.

For M42 and similar lower temperature nebulae (than planetaries anyway) I've found the H-beta filter to be smashingly good! The H-beta line is near the peak sensitivity of the eye so the dimming is tolerable and the increase in contrast is very welcome. At the old site I posted an observing report where I toured Orion's nebulae with an H-beta filter. I was even able (on an exceptionally dark, clear night) to detect the Horsehead nebula using my 80mm SV ED80 f7 and a 2" H-beta filter on a Panoptic 35mm eyepiece. Scanning M42 itself was a real treat with fine filamentary details showing where the shock fronts in the gas were.

I use the Baader H-beta some folks also use Astronomik and Lumicon. They are all of good optical quality. Disappointment with filters is mostly from folks going cheap and getting something that degrades the image.

Have you compared your beta to an H alpha?

pakarinen wrote: ↑Sat Nov 21, 2020 11:57 am Have you compared your beta to an H alpha?

Yes, just for grins. The sensitivity of the human eye peaks near H beta so for visual use the H beta is better. H alpha is better for astrophotography. I have the Baader H-alpha, H-beta, O III, and SII filters.

I thought the beta was for the horse head.

messier 111 wrote: ↑Sat Nov 21, 2020 9:02 pm I thought the beta was for the horse head.

It is much more generally useful than that! I've used it on the Flame Nebula in Auriga and the Christmas Tree in Monoceros. Seeing is believing. It is my favorite filter for not-a-planetary nebula. Restricting it to the Horsehead makes no sense to me or my eyes.

here is what I found, very interesting .
https://www.prairieastronomyclub.org/fi ... n-nebulae/

http://www.astrosurf.com/buil/filters/curves.htm

The transmission graphs in your second reference look interesting.

messier 111 wrote: ↑Mon Nov 23, 2020 5:04 pm here is what I found, very interesting .
https://www.prairieastronomyclub.org/fi ... n-nebulae/

http://www.astrosurf.com/buil/filters/curves.htm

Your first link is a resource I'm familiar with and with which I disagree, emphatically. UHC filters are to my eyes pretty much useless. Your link underestimates the usefulness of H-beta badly. I used to follow the recommendations of that link and was surprised to find that when I stepped outside its limitations things were better. Knisely's recommendations are subjective. So are mine. I can't recommend following his because in my experience, they are not helpful.

I bought an H-beta filter specifically for the Horsehead. On a whim I tried it on M42. Imagine my surprise when it outperformed Knisely's suggestion at almost anything I pointed it towards.

@j.gardavsky is the forum expert on filter usage. It would be useful if he could weigh in.

The second link is factual and therefore agreeable.

notFritzArgelander wrote: ↑Mon Nov 23, 2020 6:31 pm

messier 111 wrote: ↑Mon Nov 23, 2020 5:04 pm here is what I found, very interesting .
https://www.prairieastronomyclub.org/fi ... n-nebulae/

http://www.astrosurf.com/buil/filters/curves.htm

Your first link is a resource I'm familiar with and with which I disagree, emphatically. UHC filters are to my eyes pretty much useless. Your link underestimates the usefulness of H-beta badly. I used to follow the recommendations of that link and was surprised to find that when I stepped outside its limitations things were better. Knisely's recommendations are subjective. So are mine. I can't recommend following his because in my experience, they are not helpful.

I bought an H-beta filter specifically for the Horsehead. On a whim I tried it on M42. Imagine my surprise when it outperformed Knisely's suggestion at almost anything I pointed it towards.

@j.gardavsky is the forum expert on filter usage. It would be useful if he could weigh in.

The second link is factual and therefore agreeable.

like i said, i just find it interesting. also, it uses a 10inch most of the time.
I wonder if in a 4.75 it's worth it?

@j.gardavsky is the forum expert on filter usage. It would be useful if he could weigh in.
good idea .

messier 111 wrote: ↑Mon Nov 23, 2020 9:54 pm

notFritzArgelander wrote: ↑Mon Nov 23, 2020 6:31 pm

messier 111 wrote: ↑Mon Nov 23, 2020 5:04 pm here is what I found, very interesting .
https://www.prairieastronomyclub.org/fi ... n-nebulae/

http://www.astrosurf.com/buil/filters/curves.htm

Your first link is a resource I'm familiar with and with which I disagree, emphatically. UHC filters are to my eyes pretty much useless. Your link underestimates the usefulness of H-beta badly. I used to follow the recommendations of that link and was surprised to find that when I stepped outside its limitations things were better. Knisely's recommendations are subjective. So are mine. I can't recommend following his because in my experience, they are not helpful.

I bought an H-beta filter specifically for the Horsehead. On a whim I tried it on M42. Imagine my surprise when it outperformed Knisely's suggestion at almost anything I pointed it towards.

@j.gardavsky is the forum expert on filter usage. It would be useful if he could weigh in.

The second link is factual and therefore agreeable.

like i said, i just find it interesting. also, it uses a 10inch most of the time.
I wonder if in a 4.75 it's worth it?

@j.gardavsky is the forum expert on filter usage. It would be useful if he could weigh in.
good idea .

I used it happily in my Stellarvue ED 80mm Access from a dark site.

well finally I spoke with the people at the store where I go for my astronomical things, they let them try the filters.
h beta.
o111.
uhc lpr.
all filters are Baader.

So as soon as the weather on my side, I will do the necessary tests.
and I will take my decision at that time.

I was finally able to try the uhc filter (celestron baader) on m42.

Bortle scale 8-9 where I live.

I was very surprised with the result because at the beginning I was skeptical about filters in general.
but I must say that the filter sewn my mouth.
it was wonderful .
the nebula was much larger and more light.
such that I removed the filter to see the difference.
I put the filter back on.

I have other filters to test but the weather does not cooperate with my part of the sky at the moment.