Which filter?

bmitchell82 (Brendan) · #1 15-12-2008, 01:08 PM

Hey fellas, looking for a light pollution filter in the 1.25" variety. Bintel is selling its own brand and a orion brand for 80 rods. are they comparable to each other, or is there a better option for a good price.?

Starkler (Geoff) · #2 15-12-2008, 06:16 PM

I doubt you will find any cheaper. Better maybe, but you have to pay more for it.

Ian Robinson · #3 15-12-2008, 07:17 PM

Go for quality rather than cheapest price.

Also depends on if you want to do any imaging. Do your homework (stacks of info here and elsewhere).

Smirnoff · #4 15-12-2008, 08:34 PM

Astronomiks are really good, their coatings are super hard and can withstand some serious punishment, not to mention that they will last a very long time. At $165 a pop they ain't cheap but you are buying one of the highest quality offerings available.

http://www.astronomik.com/en/astronomik_uhc_filter.html

Starkler (Geoff) · #5 16-12-2008, 12:16 AM

I recommend you borrow and try one if you can before shelling out the $.

LPR filters are visually most effective in mild light pollution situations where a high proportion of the offending light is of a type that can be filtered.

I have only seen them give a very mild improvement and you might end up thinking you've wasted your $.

Tandum (Robin) · #6 16-12-2008, 01:29 AM

I've sold off all of the visual and photo ones I had, you're better off waiting for a new moon than throwing money away on filters.

I should add that I now have some narrowband imaging filters instead for when the moon is up

bmitchell82 (Brendan) · #7 16-12-2008, 09:32 AM

i guess im looking to use it to aid my viewing from a back yard in the middle of perth. It will be running in mainly a 10" Skywatcher, though i wouldn't mind using it in the 12" meade from time to time and maybe a little bit of photography. I don't get the chance to go out to dark sites very often. Im not worried about coloured filters I have given them a crack before and found them a bit ordinary, they really come into their own when imaging in b&w.

I have heard that Astronomik's are some of the best out there, and im still a firm beliver in buy the best your pocket can afford even if you have to move from Maggi mega noodles to Mi Goreng for a month

Anybody around perth that could aid me in a bit of show and tell for filters.

Starkler (Geoff) · #8 16-12-2008, 12:08 PM

Quote:

Originally Posted by bmitchell82

i guess im looking to use it to aid my viewing from a back yard in the middle of perth.

Then I think you will be disappointed. The effect of an LPR filter in sky background darkening in the best of cases is like going up one notch in magnification, say like the difference between a 22 and 24mm eyepiece.

Yes light pollution sux, but really there is only one solution to get around it.

A uhc type filter can help on nebulae if you drape a cloth over your head to keep extraneous light out and to aid dark adaptation.

bmitchell82 (Brendan) · #9 16-12-2008, 12:22 PM

ahhh this is the bugger i sees

. So a UHC filter is going to give me a bit of an advantage over all. or basically, its a lost cause and pretty useless overall and i should forget about it.

I do realise that the best soloution to my problem is to get out of town into some prime astro realestate but i don't have that option and would like to maximise my viewing capabilitys.

I do have good eyes and can pick up alot of detail already and use averted vision though having street lights all around me is a bit of a !@#! so to speak!

A uhc type filter can help on nebulae if you drape a cloth over your head to keep extraneous light out and to aid dark adaptation.

this might help aswell as normally i don't just have a 10 second look at the target, i have a good crack and look at it for a good 5 - 10 minutes.

Mighty_oz (Marcus) · #10 16-12-2008, 09:34 PM

Hey Brendan, i have anAstronomik CLS filter u can borrow if u like, i live sth of the river

skies2clear · #11 17-12-2008, 11:05 AM

Brendan,
personally, I think the DGM Optics NPB is the best overall filter I have, including the usual UHC types. These used to cost around $75 from Omega Optical for 1.25". Not sure how much they are now. You'd have to import it yourself.

It does a better job on most nebulae than any UHC or UHC-S filter I've tried. eg Orion M42, Eta Carinae, Tarantula nebula, etc. No good for Horse Head Nebula, but neither is a UHC filter,

Cheers

andrew2008 · #12 17-12-2008, 08:40 PM

You will probably be disappointed with the orion filter. Why? Just bought the narrowband myself. Got it out a couple of nights ago for only use so far and managed to look at Tarantula and Orion nebs fairly quickly. Could see more detail in Tarantula but Orion was much the same. Certainly isn't as good as a dark sky. Live in a complex with 3 street lights visible from only place to observe about 12km from Brisbane CBD and have limiting mag of about 4 and 5 on really dark moonless nights so really should be happy with any improvement. Also my only filter experience so can't compare to others.

Would be great if no one could buy anything this week as planning to get out of city on 1 night this weekend;-)

Prickly · #13 17-12-2008, 10:26 PM

Hi Brendan,

I use a Baader semi-apo filter with my refractor (combination of a moon and skyglow and a fringe killer). I leave it in all the time. It has a slight darkening effect on the sky and helps with the chromatic abberation. Certainly the UHCS darkens the background more and brings out more detail in some nebulae but it darkens the stars so much it cant be used as an "all rounder" on most objects. It might be worth seeing if you can find someone with a moon and skyglow and trying this out. Ive never used the moon and skyglow alone but some reports suggest it may act a little like my experience with the semi-apo. I would say the effect is subtly better but with high light throughput with the semi-apo. Certainly good on jupiter/mars too.

Cheers
David

bmitchell82 (Brendan) · #14 18-12-2008, 12:22 PM

I know the feeling of not having stars above my head, Brizvegas is pretty bad but then again so is perth the place looks like somebody grabbed marbles and throwen them around its so spread out.

I guess from what everybody is saying that these filters do work, but only marginally, but are they worth the 150-200 rods that companys are asking for them?

Prickly · #15 18-12-2008, 09:33 PM

Hi Brendan,

Tricky question. Some people will pay a lot for minor changes. I guess if you spend a lot of time observing from the back yard then it may be worth it. For me for visual the semiapo is a must and, as mentioned, I never remove the filter from the star diagonal. If you spend a lot of time looking at planets it might also be quite nice to have something like a moon and skyglow. I can really notice a difference in sky brightness without the semi-apo in place so it is noticeable although subtle. Best thing is to check out some filters at a star party. I havent tried the other LPR filters.

My UHCS is mainly for photographic. Its great for that and can double as an Ha filter if you combine it with a red filter (which is a bonus- so its a 2 in 1 filter in a way). If I was using it just for visual it would take a bit more convincing for me to buy this for the price.

Cheers
David

bmitchell82 (Brendan) · #16 19-12-2008, 11:33 AM

okay im lost here, Semiapo i thought was a type of Refractor, argh too many UHC's LPS and asssorted stuff.!

Ian Robinson · #17 19-12-2008, 12:57 PM

Quote:

Originally Posted by bmitchell82

okay im lost here, Semiapo i thought was a type of Refractor, argh too many UHC's LPS and asssorted stuff.!

This is why you have to do your homework and understand what the filters actually do , by looking at and understanding how they perform (transmission curves).

bmitchell82 (Brendan) · #18 19-12-2008, 01:31 PM

I have looked, but everything is different, they use their own versions of different filters. I did look alot at one guy who was obviously in france, and he used spectroscopy to show what the pass filters do. Astronomik proformed the best.

Though thats why i have come to this part of the forum, its not because im lasy its because with every clown on the internet confusion often sets in. and in such a specific area that i have querys with, i just want to get other peoples honest opinions before i go and buy a decent filter.

Im going to try and get a hold of these filters before i do buy one so I can see the exact difference they make.

Further to this subject, i will more than likely take the photography leg, though as i cant afford what i need just yet im forced to use what i have. so make the best of it i say!

Prickly · #19 19-12-2008, 11:44 PM

Just to clarify:

Yes, a semi-apo is generally for refractors. It is a combination of a moon and skyglow (light pollution component and reportedly good for planets) and the fringe killer (more useful for the refractor). It is very high transmission. If you have a reflector there would be little need for the fringe killer component [although the semi-apo does give a fairly neutral sort of a filter in terms of changing the hue of objects (eg planets and moon)] so the moon and skyglow would probably suffice. There are other types too but I havent tried them so I can't comment.

wavelandscott (Scott) · #20 20-12-2008, 10:38 AM

I've written about my thoughts concerning LPR filters before...in some other threads

In summary:

Do they work? ...yes they do, they will filter/or block light from streetlights etc. They are an improvement on no filter but getting out of town is much better.

Will they make your backyard a great place to view? ...no, not if you are looking for faint fuzzies...double stars, planets, the moon will be great, but you don't need a filter for those anyway...

Would I advocate buying one? ...I own one and it works (improves the ability to see certain objects) but I don't think I would encourage people to run out and get one. If you are in need of a filter I would suggest the DGM Optics NPB (narrow passband) filter...it is a cracker! It is more than a LPR...

The other related issue that was mentioned earlier is that one of the horrible things about light pollution is that your eyes never get a chance to fully dark adapt. Even with your filt filtering/reducing some of the unwanted light, everytime you raise your head up from the eyepiece, your eyes will respond to the light. A towel over your head at the eyepiece will help but eventually stray light will hit your eye and you lose your dark adaptation in a snap...

Good Luck!