Jump to content

Which filter for LP?


JamesF

Recommended Posts

I really don't have a big problem with LP. Generally when the sky is clear I it's probably only the ten degrees or so above the horizon that is affected, but there are occasions when I want to see down that low, particularly between the south east and south west, which is probably where most of my light pollution comes from.

I've been looking at filters that work for LP and there seems to be quite a choice of models that would work -- the Baader UHC-S or Neodymium, or the Skywatcher UHC or LP filter to name four and I'm sure there are others.

Can anyone suggest what might be best suited for visual use in my 10" dob (or even what might not be)?

Thanks,

James

Link to comment
Share on other sites

I'm not sure about this as I haven't tested them for both visual and imaging, but I believe they work better for imagining than for visual (please put me right if that isn't so). I have to say that I leave a Baader Neodymium filter permanently attached (whether viewing or imaging) to the diagonal as I feel it gives a clearer view than the SkyWatcher LP filter that I have.

Link to comment
Share on other sites

Hi James, both the ones you suggest, Baader Neodinium and the Sky Watcher are good, I have tried both in the 2" versions and they both work well, I prefer the Sky Watcher myself, but I also have the Orion Moon & Skyglow filter in 1.25" and that is also good in my C100ED. I only use them for visual, but all work well.

Link to comment
Share on other sites

Well, I've been thinking about getting an LP filter to fit the camera lens too, so I might split the difference and get a 2" skywatcher filter and step-down ring for that. Has to be easier than trying to get rid of the LP gradient in shots of the Milky Way that approach the horizon during processing.

James

Link to comment
Share on other sites

  • 1 month later...

Hi All

I've just purchased a skywatcher LP Filter which I'll be using with a 2x Barlow and 10mm eyepiece and a philips toucam pro2, with eye projection adaptor, my question to you all is "Do I need a separate uv/ir filter or has the skywatcher got these features already?".

I've googled but couldn't find anything, I did see on one of the other threads that someone had said that all light pollution filters have uv/ir filtering, is this correct.

Any assistance would be appreciated.

Cheers

Link to comment
Share on other sites

I have a Celestron LP filter and an APM branded UHC. I use the latter on emission nebulae a lot (LP or no LP), and the LP filter occasionally (mainly because it is a SCT-threaded filter rather than a 2"). LP filters can help a bit with galaxies IF the LP is narrowband (e.g. low-pressure sodium lights)

Link to comment
Share on other sites

http://www.karmalimbo.com/aro/pics/filters/narrow.jpg

If you only have one nebula filter, it should be a narrowband that transmits the H-Beta and O-III lines emitted by nebulae.

The link I quote has many brands superimposed on one another so you can see the different philosophies in bandwidth.

In general, narrower produces better contrast, but tends to kill the stars. Wider shows more natural stars, but at the sacrifice of best contrast.

Personal preferences enter in.

Unfortunately, there is no filter that truly enables you to see better views of stars and galaxies except gasoline--you put it in your car and drive to darker skies!

Any filter that blocks light (as in light pollution) will also make the full-spectrum objects (like stars and galaxies) dimmer.

Some examples of decent narrowband filters:

Lumicon UHC

Astronomik UHC

Orion Ultrablock

Baader UHC-S

DGM NPB

Denkmeier UHC

Thousand Oaks LP-2

Higher transmission is better, The best filter transmits 486nm, 496nm, and 501nm lines in the spectrum and very little else.

See the above link.

Link to comment
Share on other sites

I live in a badly light polluted area but dno't use LP filters per se. I have a Baader Neodymium and this works well on Jupiter, Mars and the moon and Castell UHC and Oiii. the latter work really well at a good price. personally I use more magnification to dark the sky and sometimes even mask off my big dob to reduce the exit pupil.

Link to comment
Share on other sites

In the end I bought a 2" Skywatcher LP filter for the camera lens and a 1.25" neodymium filter for eyepieces. Since mid August when I posted the original question I think I've only managed four nights though and at those times the LP hasn't been that bad so I've not exactly got a lot of use out of them. I shall remember to give the neodymium filter a try on Jupiter though.

James

Link to comment
Share on other sites

Do LP filters really make a difference especially with LED lighting? It was my opinion from reading that LP filters are not that successful. Hope I am wrong because need one in Los Angeles suburdia.

Link to comment
Share on other sites

I use the Baader Neodymium filter & so far I'm quite impressed with it.

Below 2 unguided images of M31 ok so they aren't going to win any awards the top one is a single sub of 1½ minutes & there was already an orange glow appearing & the one below was 2½ minutes with the Baader filter fitted.

IMG_3054.jpg

Andomeda.jpg

Link to comment
Share on other sites

Hi James,

I wonder if you've had a chance to try the neodymium filter on Jupiter (or indeed at all) yet? I'd love to hear your thoughts on it - I'm very tempted by one myself but haven't come across any reviews that had had me rushing for the checkout yet.

Would be very curious to know how you'd found the LP filter too - also on my shopping list!

Hope you've found them to be helpful.

Derek

Link to comment
Share on other sites

Not yet :(

I've been lazy of late and haven't written up my observation notes. Did that today because work was rather slow. The last time I was out when much visual was on the cards was 8th September :( I've managed one more night since which was Saturday and I spent that imaging the full moon.

The forecast earlier was for a clear night tonight, but when I went out at dusk to shut up the chickens it was absolutely pouring down. It's all rather depressing :(

James

Link to comment
Share on other sites

I find mentioning the local foxes tends to keep them quiet :)

Actually, they're mostly pretty good. There's one cockerel who insists on sleeping on the roof of the chicken house and a hen that has taken to roosting in one of the apple trees, but other than those two they mostly take themselves off to their house as it starts to get dark and I just need to go around and close the doors.

James

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.